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HARVARD UNIVERSITY

LIBRARY

OF THE
MUSEUM OF COMPAKATIVK ZOOLOGY

THE

PALiEONTOGRAPHICAL SOCIETY.

INSTITUTED MDCCCXLVII.

LONDON:

MOCCCLXIII

SUPPLEMENTARY MONOGRAPH

OK THE

MOLLUSCA

FROM THE

STONESFIELD SLATE, GREAT OOLITE, FOREST
MARBLE, AND CORNBRASH.

BY

JOHN LYCETT, M.D.

LONDON:

PRINTED FOR THE PALiEONTOGRAPHICAL SOCIETY.

1863.

J. E. ADLARP, PttlNTEK, BAHTHOLOJIEW CLOSE.

INTRODTJCTOEY EXPLANATION.

The introduction to the first part of the ' Monograph of the Great Oolite MoUusca '
contained an intimation that, with increasing knowledge of the testacea of the Cornbrash
and Forest Marble, it might eventually be desirable to give an additional monograph, or
an Appendix to that work. The materials which have latterly been placed at the disposal
of the writer are so considerable that he has been induced to endeavour to fulfil the
anticipatory announcement made in 1850, and also to correct some errors, both textual
and typographical, which occur in the former Monograph. In the execution of his task
the writer begs thankfully to acknowledge the assistance he has received in the loan of
specimens from gentlemen whose names will be found mentioned in connexion with each
of the species illustrated, nor can he omit gratefully to mention the great advantages he
has derived from the constant opportunities that have been afforded to him of comparing
the Oolitic fossils of the southern counties with those of Yorkshire, contained in the very
extensive and choice collection of Mr. Leckenby, of this place.

Scakborough; September (>, 18G1.

SUPPLEMENT

TO

A MONOGEAPH

OF THE

MOLLUSCA FROM THE GREAT OOLITE.

CEPHALOPODA.

Ammonites Bullatus, D'Orhijj. Tab. XXXI, fig. 1.

Ammonites Bullatus, D'Orb. Pal. Fr. Ter. Jiirass., p. -112, pi. 142, figs. 1 .ind 2.

— — Kiideniatsch. Abliand. K. K. Gcol. Reich., 1 band., taf. iii,

figs. 1—4—11.

— PL.\TYSTOMUS, Qiienst. 1 Cephal., t. 15, fig. 3.

— Bullatus, Oppel. Juraform., p. .519.

— — Quenstedt.1 Der Jura., t. 64, fig. 13, p. 4/9.

Testit hullaid, irrec/uJari ; anfractibits subinvohitis, latis, ultimo (mgusiato, transversim
late costtato ; costis iiupqiialibus ; aperfiint constrictd, semiliinari. (D'Orliigiiy.)

Shell inflated, globose, variable in form throughout all the stages of its growth, onia-
uiented with large, transverse, slightly elevated ribs, which pass from the lunbiliciis over
the back to the other side, not straight, but curved forwards ; these are separated by other
shorter ribs, which alternate with the larger series of ribs in the adult state, but in the
young state there are two and sometimes three short ribs between each of the longer
ones. The volutions of the spire are irregular and embracing, forming a contracted um-
bilicus in the young state ; subsequently the volutions are less contracted, which renders
the shell unsymmetrical or deformed. The back is rounded, the mouth much contracted
and prolonged in the middle part. The septa are very much complicated.

In England this Ammonite is very rare. The aged example figured is seven inches in

4 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

diameter, the aperture having a height and breadth of two inches ; its more advanced
growth will account for the difference of ligure when compared with those of D'Orbigny,
Qnenstedt, and of Kudernatsch ; but in truth, the variability of figure extends not less
to individuals than to the stages of growth, for in no instance does there appear to be a
very near agreement of figure.

Geological Position and Localities. The sole specimen in my collection is from the
Great Oolite, near Tiltups Inn, two miles south of Nailsworth ; another specimen,
apparently from the same locality, is in the collection of my friend, Dr. Wright, of Chelten-
ham. The foreign localities are St. Maixent, Deux-S^vres ; Masigny, Vendee; Nantua,
Ain ; Vezelay, Yonne ; Wohnkammer, Swinitza.

Ammonites discus, Sow. Tab. XLI, fig. S, S a.

N.vrTiLUs DISCUS, Sow. Min. Con., 1813, i, (ab. 12.

Ammonites discus. Sow. Ibid., 1815, Suppl. Ind. to toI. i, p. 5.

— — Morris. Catal., 1854, p. 291.

— — Oj)pel. Juraformation, p. 472.

Testa discoiclea, angiisto umbilicato, dorse angusto acute carinatis, laterihus externe,
valde comprcssis, Icevigatis ; apertura sagittceformi. jStatc jitnion laterihus costis dis-
tan fib us fexuosis.

Shell discoidal, with a narrow and deep umbilical cavity, the back acutely keeled ; the
sides of the volutions near to the back are much flattened and smooth ; the aperture is
sagittate, the margin of the umbilicus is rounded. In the young state, when the diameter
does not exceed three inches, the sides are ornamented with regular distant, depressed,
flexuose costae.

The lobes are comparatively simple, with few ramifications, and have but little depth ;
the saddles are in a corresponding manner but little produced ; they therefore differ
altogether from the septa of A. discus, D'Orbigny, and from the A. sub-discus, of the same
author; tliey are, however, more complicated than is seen in A. discus, Quenst.
(' Cephalopoden,' tab. viii, fig. 13); A. Sfauffensis, Oppell, from the inferior Oolite of
Boll, Balinger, &c. They also differ from the description given by Roemer (' Nord.
Ool.,' p. 190) of an Ammonite attributed by him to A. discus, Sow., from the lower Coral
Rag of Heersum.

The general figure is less discoidal than A. Waterhousei, Mor. and Lye. {A. discus,
D'Orb.) ; it differs also from that species by the absence of the flattening upon the inner
portion of the sides of the volutions. From A. sub-discus, D'Orb., the general figure
differs in the more acute back and in the smaller umbilicus.

The specimen figured in the ' Mineral Conchology,' is an adult shell, and smooth ; the fine
specimen selected for our illustration exhibits the septa, and also some traces of the
falciform costaj proper to the young shell. I am obliged to Mr. Woodward, of the British

GASTEROPODA. 5

Museum, for information respecting it, and also for a careful drawing which exhibits its
palasontological features ; the specimen was obtained in the Bradford Clay of the Tetbury
Road Railway Station, near Cirencester, by Professor Coleman, of the Royal Agricultural
College.

Geological Positions and Localities. It has occurred at several localities in the Corn-
brash, as at Wollaston, Chippenham, Trowbridge, and in Bedfordshire, but it is every-
Avhere rare ; to these positions must be added the single specimen above alluded to from
the Bradford Clay, and another, in tlie British Museum, from the slate of Stonesfield.

GASTEROPODA.

Brachytrema varicosa, Lf/c. Tab. XLIV, fig. 27.

Testa parva ovata , gihhosa , sjoira anfractibus 5 suhplanis, costis transversalihus ellongi-
tuilinalihus inaqualibus cruciatis ; (/rannlatis, (/rannlis magnls, dejiressis, ultimo anfractu
varicibus irregidaribus duobus ; ajjertura sinuosa, columella arcuafa, canuli breviicsculo.

Shell small, ovate, gibbose; spire elevated, obtuse, consisting of five, flattened volutions,
with well-marked sutural depressions ; encircling costae five, of which the first and last
are large, forming elevated bands, the three intermediate costas being smaller, irregular,
and unequal ; they are decussated by very irregular, granulated, straight costae, which
occasionally form large varices, of which the last volution has two ; these impart a distorted
aspect to the lower part of the shell; the aperture is rather narrow and sinuated, the
columella much curved, the canal short, the notch narrow and deep; the outer lip is
thickened, but imperfect.

A short, ovate shell, with strongly marked and very irregular ornamentation ; the
varices are prominent only upon the two latter volutions ; the straight costae are very
irregular, sometimes crowded, but occasionally very distantly arranged; the basal canal is
unusually short, and curved forwards ; the lips are without denticulations.

Geological Position and Locality. The Great Oolite of Minchinhampton Common ; very
rare, two specimens.

Brachytrema buccinoidea, Lgc. Tab. XLIV, fig. 17.

Testa turricidata, ovali veniricosa, anfractibus 5 — 4 convexis, suturis valde impressis,
lon//iti(dinaliter costatis, costis 14: — IG reef is, transversimjinissime lineatis, anfractu tdtimo
magno, rotundo, basi attenuate, cancdi brcvi, obliquo ; apertura superne et inferne constricto.

Shell turreted, ovately ventricose, volutions 5 — 4, convex, the sutures deeply impressed,
longitudinally costated; the costae, from 14 to 16 in a volution, are perpendicular, and not
very strongly defined ; they are decussated by fine, encii'cling lines ; the last volution is

6 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

large, rounded, attenuated at the base ; the canal is short and oblique ; the aperture is
much contracted at the two extremities.

Geological Position and Locality. The Great Oolite of Minchinhampton, collected by
E. Witchell, Esq., of Stroud.

PuRPtFROiDEA iNsiGNis, Zj/c. Tab. XXXI, fig. 2, 2 a.

PuRPUROiDEA INSIGNIS, Lyc. Cotteswold Hills Handbook, &c., pi. 7, fig. 8, a, b.

Testa turbinata, ovafa, iiijlata, sjrira exserta, anfractibus 5 siibangulatis, tuberculis
depressis {9 171 ambitu), anfractu ultimo magno inflato, plerumque sine tuberculis; aperturd
onagnd ovatd, canali leviter excavato

Shell turbinated, ovate, inflated ; spire half the length of the aperture ; volutions (5)
slightly angulated and flattened upon their upper surfaces, with nine small, depressed
tubercles upon each volution ; the last volution large, ventricose, rounded, the latter half
of the circumference being destitute of tubercles, and having only oblique folds of growth ;
aperture ovate, columella with an umbihcal groove ; the basal notch is only slightly
defined, the junction of the columellar and outer lips forming a gentle curvature. The
shorter, angular spire, depressed tubercles, and ventricose figure of the last volution, serve
to distinguish it from P. nodulata, the species to which it is most nearly allied. The
expanded base, wide, shallow, or obsolete notch, and rounded columella, so constant in all
the species of Purpuroidea, appear to me to justify a generic separation from the recent
Purpura, to which they have been reunited by some French palaeontologists of eminence.
The genus Purpurina of D'Orbigny, exemplified by his type P. Bcllona, is separated
from Purpuroidea both by the figure of the aperture and by his description, in which the
contracted basal canal is insisted upon ; other so-called examples of Purpurina, in the
' Paluontologie Fran^aise,' as Ornata, Bianor, Bixa, and Batliis, have, together with a
thin shell, a lengthened, subulate figure and an entire aperture ; these should be placed with
the Littorinidte, and should range by the side of Amberleya, figured and described in the
first part of this monograph. I am inclined to claim for Amberleija a more important
position than that of a sub-genus.

The Great Oolite species of Purpuroidea have, however, been merged by Professor
Morris (' Catalogue') and by Dr. Oppcl (' Juraformation') with Purpurina.

Geological Position and Locality. The Great Oolite of jMinchinhamptou Common,
associated with other species of the same genus.

Cerithium BATnoNicuM, Li/c. Tab. XLIV, fig. 19.

Testa parva subconica, apice obtuso, anfractibus Idtis, paucis, pldnis ; costis (7) rectis
magnis, obtusis, striisque cingendis ; apertura parva, cauda brevi.

Shell small, somewhat conical ; apex obtuse ; volutions wide, few, flattened ; costte (7)

GASTEROPODA. 7

straight, large, obtuse, encircled with regular striations ; sutures of the volutious distinctly
marked.

The costa3 form straight, rounded elevations, Aviiich pass the whole length of the spire,
and are only slightly interrupted by the sutures, the height of each volution being equal
to about two thirds of its opposite measurement. It appears to be rare.

Length three lines, breadth half the length.

Geological Position and Locality. The upper beds of the Great Oolite near Bath,
associated with numerous other minute testacea, collected by Charles Moore, Esq.

Ceritiiium bulimoides, Besl. Tab. XLIV, fig. 3.

Cekithiuji bulimoides, Beslongchamps. Mem. Soc. Linn, de Normand., 1848,

vol. viii, pi. 11, fig. 40.
— — B'Orb. Prodr., i, p. 303.

Testa minima, elongato-tunita, acuta, anfractibus rotundatis, transvcrsim sfriatis, longi-
hidinalitcr costatis, costis rectis, lasi oLliqica, transverse striata, apertura suhrotunda,
columella marginata, canali mdlo. (Deslongchamps.)

Shell minute, elongated, turreted, acute ; volutions (8) slightly convex, wide, trans-
versely striated and longitudinally costated ; costae about S in a volution, perpendicular
and obtuse ; the sutures are deeply impressed, the aperture is oblique and rounded ;
there is no basal canal.

The costoe, which are large and elevated, are slightly knotted where they are crossed
by three encircling lines in each volution ; our specimen is imperfect at the base.

Geological Position and Localities. The Great Oolite of Minchinhampton, collected
by E. Witchell, Esq. France, Luc.

Cerituium multivorme, Piettc. Tab. XLIV, fig. 20.

Cekithiuji multifoume, Piette. Bull. Soc. Geol. Fr., 2 ser., t. 14, pi. .5, p. 553.

Testa parva ehngato conica, anfractihus (9 — 10) angustis, convcxis, siitttris valde im-
pressis, costis si(hohliquis {\0 ad 12 in amditii), magnis, lineis cingendis [^) cecpialihus ;
anfractu ultimo ad basin lincato, caiida brevi.

Shell small, elongated, conical; volutions (9 — 10) narrow, convex, the sutures deeply
impressed; costas large, from 10 to 12 in a volution, longitudinal, but slightly obHque,
and knotted by five rows of regular encircling lines, the last volution has encircling lines
at the base ; the canal is short.

The tumid, narrow volutions, large costse, and deep sutures, afford strong distinctive cha-
racters, the height of each volution being only slightly greater than a third of its opposite
measurement. The specimens figured by ]\I. Piette vary nuich in the elevation of the spire,
and consequently in the breadth of the volutions ; the number of costic likewise differ.

8 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Geological Position and Locality. The Great Oolite of Kirklingtoii, Oxon, collected
by J. F. Whiteaves, Esq. Eparcy, France.

CERITim'M? STRANGULATUM, Afcldac. Tab. XLIV, fig. 2.

A shorter and less cylindrical variety of this species was figured in the first part of the
' Great Oolite' Monograph, plate ix, fig. IS. The present specimen, which agrees more
nearly with the example figured by D'Archiac, has )seven longitudinal costae, which are
conspicuous even to the base ; the contracted, pupaeforni aperture, with its prominent lips, is
alike in both varieties.

Cerithium stranc/ulatum, C. Bulimoides, C. spicidum, and C. exi(jua, belong to a small
group of minute, subcylindrical shells, with prominent, longitudinal costte, and small,
thickened, orbicular apertures, which have been referred to Cerithium and to Rissoa ;
perhaps eventually it may be deemed proper to separate them under a new generic
appellation.

Geoh(jical Position and Locality. The Great Oolite of Minchinhamptou Common ;
rare.

Ckeithium undulatum (var.), BcsL, sp. Tab. XLIV, fig, 6.

MiiLANiA u.NDULATA, Beslotigchamps. Jk'm. Soc. Liim. de NormauJ., 1842, vol. viii,
pi. 1 1, fig. 58, var. a.

Testa tiirrita ; anfractihus ^jlanis, transversim strialis, ad sutiiras crenulatis, longitudi-
naliter costatis, in tdtimo anfradu costis siibinciirvis, basi obliqua, striata; apertura
elliptica, obliqua, columella marginata ; labro sinistro fissuram umbilicateni obtigente.

Var. a, testa breviori, costis et striis crassioribiis, rariorisque. (Dcslongchamps.)

Shell minute, turreted ; volutions flattened, transversely striated, crenulated near to
the sutures, and longitudinally costated ; aperture elliptical, oblique.

Our example constitutes a small and short variety, with narrow volutions (about 8) ; the
costa) are large, straight, and from 7 to 8 in a volution ; they are most conspicuous near
to their upper extremities, which project, forming a kind of coronary border immediately
beneath the suture. Another minute specimen, apparently belonging to the same variety,
has the first three volutions almost plain, and the costae upon tlie succeeding volutions are
but little prominent.

The typical form of the species figured by M. Dcslongchamps has the costae much
more numerous and less prominent.

Geological Position and Locality. The Great Oolite of Minchinhampton, collected by
E. Witchell, Esq.

GASTEROPODA.

RissoA? EXiGUA, Lyc. Tab. XLIV, fig. 11.

Testa parva, ovato-conica, spira anfractibus (6) piano -convexis, amjustis, suturis valde
impressis, cofitis hnf/itudinalihus redis, angustis, 8 — 9 in ambitu ; apertura, parva, sub-
orbiculari, labro externa simplici.

Shell small, ovately conical ; spire consisting of six flattened or slightly convex, narrow
volutions, the sutures being strongly marked ; longitudinal costse elevated, narrow, per-
pendicular, 8 to 9 in a volution ; aperture small, suborbicular, outer lip simple.

A minute lenticular shell, with about eight and a half costal spaces to a volution, the
height of each volution being equal to the half of its transverse diameter ; the apex is
slightly obtuse, and the last volution is somewhat contracted.

Geological Position and Locality. The Great Oolite of Bussage, collected by Mr.
Witchell.

Cerithium? spiculum, Lyc. Tab. XLIV, fig. 1.

Testa ovafo-elongafa, minuta, anfractibus (6) latis subplanis, transversini striatis etlon-
yitudinaliter costatis ; costis rectis {^in ambitu), anfractu ultimo cylindrico, apertura parva,
ovata, canali nullo.

Shell minute, ovately elongated subcylindrical ; volutions (6) wide, rather flattened,
transversely striated, and longitudinally costated ; costae straight, six in a volution; the last
volution is nearly cylindrical ; the aperture is small, ovate ; there is no canal.

The costse, which have little prominence, appear to stretch continuously ; the length of
the shell only slightly interrupted by the sutures, which are not strongly marked ; the aper-
ture is pupaeform ; the general figure approximates to C. stranyulatum, but more lengthened,
and with higher volutions.

Geological Position and Locality. The Great Oolite of Minchinharapton.

Cerithium ? compositum, Lyc. Tab. XLIV, fig. 9.

Testa parva, elongato-conica, anfractibus (6) angustis subplanis, transverse striatis et
costatis ; scilicet anfractu ultimo et penultimo costis crebris longitudinalibus rectis, circa
1 8 in ambitu ; apertura parva, obliqua, ovata, depressa.

Shell minute, conical, elongated; volutions (6) narrow, flattened, transversely striated,
and longitudinally costated ; but the costae are limited to the two or three latter volutions,
they are closely arranged, little elevated, and about eighteen in a volution ; the aperture is
depi'essed, oblique, and ovate.

10 SUPPLEMENT TO GREAT OOLITE MOLLUSCvV.

Geological Position and Localifij. The Great Oolite of Minchinhampton, collected by
Mr. Witchell.

Cerithium? Witch elli, Zj/c. Tab. XLIV", fig. 7.

Testa minuta suhcylindrica, elongata, anfractibus (5 — 6) suhconvexis altis, suturis valde
impressis, costis {circa 15) depressis subrectis, superne distindis, i7iferne evanescentibus
aperiura ovata, labro externa siwplici.

Shell minute, subcylindrical, lengthened; volutions (5 — 6) high, rather convex, the
sutures depressed and strongly defined ; costse (about 15 to a volution) depressed, distinct
at the upper and vanishing towards the lower part of each volution ; the aperture is of
moderate size, ovate, the lips rather thickened.

The breadth of each volution is about one third more than its height ; the costae are
only faintly marked ; there are no traces of encircUng striations or tubercles.

Geological Position and Locality. The Great Oolite of Minchinhampton, communi-
cated by E. Witchell, Esq.

Cerithium ? pulchrum, Lye. Tab. XLIV, fig. 4.

Testa parva, crassa, turrito-subulata, anfractibus (8) convexis, suturis valde impressis,
costis transversis, obliquis, magnis {circa 12 in ainhitu), lineis longitudinal ibus decussatis,
apertura parva ovata, canali nullo.

Shell small, thick, elongately turreted ; volutions 8, convex, the sutures deeply im-
pressed ; transverse costse about 12 to each volution, oblique, large, decussated, and
rendered nodulous by six narrow encircling lines ; aperture ovate, rather contracted ; no
canal.

Allied to Cerithium costellatum, Desh., from which it differs in having fewer volutions,
and in possessing encircling lines. C. bulimoides, Desh., with a similar general figure, has
the costaj smaller, fewer, and perpendicular.

Geological Position and Locality. The Great Oolite of Minchinliampton Common,
collected by Mr. Witchell.

Nerin^a granulata, Phil., sp. Tab. XXXI, figs. 12, 12 «.

Terebea granulata, Pkil. Geol. York., i, pi. 7, fig. 16, p. 173.
Cerithium granulatum, Mor. Cat. Brit. Foss., \SbA, p. 240.

Testa subulato-turrita, anfractibus numerosis angustatis, planis, sed inferne subconcavis,

GASTEROPODA. 11

lineis suhnodulosis irregularibus, incequalibus (9-10) cingendis ; apertura olliqua, columella
uno plicaio.

Shell elongated, tiirreted; volutions numerous (about twenty), narrow, flattened, but
slightly contracted towards the base of each volution, and encircled with numerous (nine
or ten) irregular, unequal, slightly nodulous lines ; the aperture is small, subquadrate, and
oblique, the columellar lip has a single strong plication.

The volutions are narrow, so that their height is little more than the half of their
opposite diameters ; the upper border of each is rendered prominent by the slight contrac-
tion towards the base of each volution ; the single strong fold upon the pillar lip, and a
trace of another mesial fold upon the outer lip, is all that can be ascertained from the
single specimen at our disposal, which is also the type figured by Professor Phillips.
Sixteen volutions are preserved, but probably four more would be required to render the
spire perfect. Nerinaa fasciata, Voltz, approaches this species nearly, both in the general
figure and in the ornamentation; judging, however, from specimens obtained in the Coral Rag
of Yorkshire, the latter has the encircling lines more regularly disposed, and more constantly
and regularly nodulous ; the spiral angle also appears to be somewhat greater : it is there-
fore preferable to regard them as distinct species. The length of the imperfect specimen
above referred to is an inch and a half, to which should be added two lines to perfect the
spire ; the transverse diameter of the last volution is three lines.

Geological Position and Locality. The sole example in the Scarborough Museum was
obtained in the Cornbrash of that locality.

Ceritella minutissima, Lye. Tab. XLY, fig. 5.

Testa niinuta, elongata, spira an/ractibus (4) elevatis, subplanis ; aperura ovato-elongata ;
columella contorta.

Shell minute, elongated ; spire with the volutions elevated, smooth, and flattened ; the
last volution is large, moderately convex, attenuated towards the base ; the aperture is of
moderate dimensions, ovately elongated ; the columella is contorted at the base, as is usual
in the genus.

The length of the aperture slightly exceeds one third that of the entire shell. It is
allied to some of the varieties of Ceritella parvula (Actaeonina), but is more subulate ; it
also approaches to Tubifer Gerandoseus, Piette, but is less attenuated than the latter

shell.

Geological Position and Locality. Obtained, both by Mr. Witchell and myself, in the
Great Oolite of Minchinhampton.

12 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Ceritella Lycettea, Buv., sp., Li/c. and Mor., sp.

Ceritella bissoides, Mor. and Lye. Gr. Ool. Monog., i, tab. 9, p. 7, 1850, non
Pleurotoma rissoides, Buv. Mera. Soc. VerJ., t. ii, pi. 6,
fig. 9.
Orthostoma Lycettea, Buv. Paleont. de la Mense Atlas, p. 32, 1852.
TuBiFEK PLICATUS, Piette. Bull, de la Soc. Geol. de France, 2 se'r., t. xiii, pi. 13,
p. 587, figs. 7—8, 1857.

I avail myself of the opportunity of giving another figure of this pretty species of
Ceritella, as the magnified figure in Plate IX does not sufficiently exhibit the neatness and
angularity of the volutions of the spire. M. E. Piette, in a memoir entitled " Descrip-
tion des Ceritheum enfouis dans les depots bathoniens de I'Aisne et des Ardennes," pub-
lished in the work above quoted, rejects the claim of Ceritella to be regarded as a new genus ;
but figures the present and also another Minchinhampton species of Ceritella as examples of
his proposed neto genus Tubifer, under the names of Tubifer plicatus and Tnbifer Acfeonifor-
mis. It is a satisfaction to discover this singular and unwitting testimony to the correctness of
our appreciation of this generic form.

In the Atlas to the ' Palaeontology of the Mense,' page 32, M. Buvignier shows that we
were mistaken in supposing that our little Ceritella is the Pleurotoma rissoides of that author's
memoir above quoted, and which he subsequently assigned to his proposed new genus
Orthostoma ; in this instance, also, our genus Ceritella has the priority.

Ceritella Morrisea, Buv., sp. PI. XLIV, fig. 22.

Ceritella longiscata. Gr. Ool. Monog., i, tab. 9, fig. 14, p. -10, non Pleurotoma

lonyiscata, Buvig., Mem. Soc. Phil. Yeidun, pi. 6, fig. 8.
OiiTUOSTOMA MoREisEA, Buviff. Paleout. de la Meuse Atlas, p. 32.

In this, as in the last species, the indifi^erent figures in the earlier memoir of M.
Buvignier led to the error of assigning oiu* Great Oolite shell to his Pleurotoma lonyiscata ;
the specific name proposed by that gentleman in his ' Palaeontology of the Meuse ' is here
adopted.

Ceritella tusiformis, Li/c. Tab. XLV, fig. 4.

Testa purva elongata, fusiformi, IcBce ; ait/raclibus 5, latis, subjjlanis, anfradu
ultimo mapio, subci/lindrico, apertura eloiujuta, ai\<justa, antice et piostice valde contracto.

Shell small, elongated, fusiform, smooth ; spire moderately elevated ; volutions 5, wide
and nearly flat, the last volution large and cylindrical ; the aperture is elongated, narrow,
and nmch contracted at both its extremities, its length slightly exceeding that of the
spire.

GASTEROPODA. 13

More fusiform than other known EngHsh examples of the genus.
Geological Position and Localit//. The Great Oolite of Minchinhampton, collected by
Mr. Witchell.

Natica Hulliana, Li/c. Tab. XLI, fig. 2.

Testa ovafa, suhglohosa Iccvi ; anfractihus 6 valde convexis, sufuris profunde impressis,
spira elevato, acuto ; apertura oblique ovali, antice rotundata postice angidata ; columella
callosa, umbilico nullo.

Shell ovate, subglobose, smooth ; volntions (6) very convex, the sutures deeply impressed;
the spire is elevated, acute, the last volution being very large ; the aperture is ovate,
oblique, the anterior side rounded, the posterior side acute, the length exceeding a moiety of
that of the entire shell ; the columella is I'ounded, thickened, and there is no umbilicus.

Allied to N. intermedia. Tab. VI, fig. 1, but with a more elevated acute spire, more
deeply depressed sutures, and a more globose ultimate volution ; specimens vary somewhat
in the figure of the last volution, but the acute, elevated, deeply sutured spire will always
serve to distinguish it.

Geological Positions and Localities. I have obtained it in the Great Oolite of
Minchinham|)ton, and in the Inferior Oolite of the same locality ; Mr. Whiteaves has also
kindly forwarded to me a specimen from the Great Oohte of Kirklington, Oxon; the latter,
which is a young form, has the last volution slightly more globose than in the other
examples.

EuLiMA? l^vigata, Lgc. Tab. XXXI, fig. 3.

Testa parva Icevigata, suhulata, acuta, anfractibus [circa 10) planatis, angustis, sufuris
i/itpressis ; apertura suborbiculari obliquo, umbilico nullo.

Shell small, smooth, elongated, apex acute; volutions (about ten) narrow, their sides
flattened, the sutures distinct but not constricted ; the aperture is obliquely orbicular ; there
is no umbilicus.

The height of each volution slightly exceeds the half of the opposite diameter ; length,
nine lines ; diameter of the last volution, three lines.

Compared with U/dima ? communis, the spire is more acute, the volutions more flattened,
and the sutures are less deeply impressed.

Geological Position and Locality. It occurs rarely in the Cornbrash of Scarborough ;
the example figured is from the collection of J. Leckenby, Esq.

14 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Chemnitzia vittx\ta, TML, sp. Tab. XXXI, fig. 10.

Melania vittata, Phil. Geol. York., p. 116, pi. 7, fig. 15;
Chemnitzia vittata, ly Orb. Prodr., xi, et No. 29, p. 208.

— — Mor. Cat., 2nd edit., p. 242.

— — Oppel. Juraformation, p. 479.

Testa crassa, turriia, elongata, apice acufo, anfractibus {circa 10) latis, in medio suh-
depressis, ad stituras elaiis, carinis duohus inst metis, suturis valde depressis ; apertura,
ovata basi anc/wstata.

Shell thick, smooth, turreted, elongated, apex acute; volutions (about 10) wide, rather
depressed in their middle parts, elevated both above and beneath near to the sutures,
forming two narrow, equal, cord-like carinse ; the sutures are deeply impressed ; the aper-
ture is ovate, rather small and contracted towards the base, where the extremity of the
columella is conspicuous ; the last volution is rendered somewhat angulated by the promi-
nence of both the encircling carinse ; the surface is shining, with large plications of growth ;
a magnifier also discloses delicate, nearly regular, distantly arranged, encircling, granu
lated hues (about 20 to a volution), or when the surface has been slightly abraded, they
appear as punctated striations.

Length, 4^ inches ; transverse diameter of the last volution, 1 inch ; the height of each
volution is equal to 3-5ths of its transverse diameter.

The general figure is that of a lengthened cone, and the outline does not exhibit that
step-like figure seen in some other allied species, as in Chemnitzia turris (Desk), C. coarc-
tata (Desk), and C. condensata (Desk). The two narrow and equally elevated cord-like
cinctures which bound each volution, together with the somewhat angular figure of the last
volution, separates it from the foregoing and all other known examples of the genus;
perhaps the encircling granulated lines may also constitute a good distinctive character
but it can only be discovered in very well preserved specimens. A Chemnitzia, in the
Inferior Oolite of the Cotteswolds and of the south-western counties, which does not
appear to have been figured or described, approaches near to C. vittata, and has sometimes
been regarded as identical with it ; there can, however, be no difficulty in separating
specimens of the two forms, when they are well preserved. The Inferior Oolite shell is
somewhat less conical, or more subulate ; the sides of the volutions are more flattened ; the
upper cincture is rounded and distinct, but comparatively small ; the lower cincture is
angulated, and not cord-like; the last volution is destitute of the prominent lower cincture,
which imparts an angularity to that part in the Cornbrash shell ; the general figure of that
volution is more lengthened and pyriform, so that the base of the aperture is wider and
more produced. The Inferior OoHte shell also does not exhibit any trace of the encircling
granulated lines ; but possibly the test has not been preserved with sufficient delicacy to

GASTEROPODA. 15

exhibit this feature, even if it originally existed ; the plications of growth are also very
large, so that in the latter volutions they render the carinte distinctly nodulous ; in
C. intfata the carinse are but slightly modified by this cause.

D'Orbigny, ' Prodrome,' has suggested that Nerinaa siiprajurensis, D'Archiac, may
be C. vitfata ; but, judging from the figure of D'Archiac, N. siiprajurensis is more slender,
with the volutions much more numerous and more narrow, the sutures are also desti-
tute of that deeply indented figure which is so conspicuous in our Cornbrash shell.
The general resemblance which C. vittata bears to some examples of the genns Nerinaea
has led me to make a longitudinal section of it, and thus to ascertain with certainty that
it cannot be assigned to that genus.

Geological Position and LocaUtij. The Cornbrash of Scarborough and Gristhorp ; it is
not rare, but is very difficult to disengage from the hard limestone.

KiLVERTXA, Gen. Nov.

The views expressed on CeritJtium strangulatuni , p. 8, suggesting the propriety of
erecting a new genus for the reception of that and other allied forms, have subsequently
been strengthened by the examination of well-preserved specimens from the Forest
Marble of Somerset and Wilts, in the collection of W. Walton, Esq., of Bath. I have
now, therefore, no hesitation in proposing for these the new generic appellation Kilvertia,
which will be found described in the Addenda.

Kilvertia constricta, Lye. Tab. XLIV, fig. 8.

Testa parva turrita, elonr/ata, anfractibus (8) superne j)lanalis, inferne ventricosis, siifuris
bene distinctis, lineis transversalibiis et loni/itudinalibus, delicatissimis, ca^iceUatis ; apertura
suborbicidari depressa, incrassato.

The height of each volution is about equal to half its opposite measurement, the first
encircling line beneath the suture is rather more prominent than the others; altogether
there are six ; their size and distances correspond nearly with the lines by which they are
decussated ; the aperture is imperfect at the outer lip, there is no umbilical chink.

Geolopieal Position and Locality. A minute univalve, obtained by crushing shelly
portions of the Great Oolite of Minchinhampton Common ; Mr. Witchell has also kindly
forwarded a specimen obtained by him at the same locality, and in the same manner.

16 SUPPLEMENT TO GREAT OOLITE MOLLUSC A.

Genus — Fibula, Piette, 1857.

Description des Cerithuan enfonis dans les depots bathoniens de I'Aine et des Ardennes, par M. Ed.
Piette, ' Bull, de la Soc. Ge'ol. de France,' 20 Avril, 1857.

M. Piette has founded his proposed genus upon a small group of lengthened spiral
univalves which possess characters intermediate and approximating them to Turritella and
to Cerithium. A rounded, straight columella, with a rudimentary umbilical groove near
the base, is combined with an arcuated outer lip slightly notched posteriorly at the suture ;
the base of the aperture forms a slight canal at its junction with the anterior extremity of
the columella, or in other instances there is no canal, the base being rounded and entire,
depending upon the exact period of growth at which the animal perished ; the surface of
the volutions is plain, or slightly ornamented with oblique costfe. The author has figured
and described several species, and has characterised his genus in the following terms : — " Le
principal charactere du ce genre est d'avoir une columella droite. Le bord libre estarque,
legerement echancre a sa partie posterieure, pres de la suture. L'ombilic n'est souvent
que nidimentaire, a peine indique, et affectant seuleraent la columelle exteme. D'autres-
fois, il penetre tout le spire. Un caractere trfes curieux que j'ai remarque sur plusieurs
espcces de ce genre, mais que je n'ai pu encore constater sur toutes, c'est que la columelle
se termine parfois interieurement par un canal rudimentaire; que le mollusque forme ce
canal et le rebouche tour a tour, pour le former ensuite de nouveau en grandissant.

. , . Ainsi il arrive souvent que parmi plusieurs Fibula d'une meme espece, les
unes semblent se rapprocher des Cerithium, les autres des Turrit elles. Cela depend du
moment ou elles out peri."

In admitting the generic value of Fibula, it becomes necessary to arrange with it the
following Jurassic Testacea: — Chcmnitzia phasianoides (Mor. and Lye). Cerithium Roissii
(Mor. and Lye), Turritella Boissii (D'Arch.), and Cerithium suturale (Buvignier). The
Great Oolite of Oxfordshire and of Minchinhampton has supplied the two following
additional species.

Fibula variata, Li/c. Tab. XXXI, figs. 4, 4 a.

Testa turriculata, subventricosa ; spira elon^ata, acuta, ItBve, anfradibus (11 — 12) con-
vexiusctdis, ant/ustis, suturis valde impressis ; ultimo anfracfu si/mmetrico-curvato ; columella
interdum ad basin stibcanalicidato, aut integro, labro sinistra arcuato.

Shell turriculated, somewhat inflated ; spire lengthened, acute, smooth, consisting of
11 or 12 narrow, somewhat convex volutions, with deeply impressed sutures; the last
volution is conformable with the others, and is symmetrically curved towards its anterior

GASTEROPODA, 17

extremity ; the aperture is oblique, contracted at the base, sometimes slightly channelled,
in other instances entire and rounded ; the outer lip is much curved and thin. Young
specimens are less subulate, but the apex is delicately pointed, the volutions are more flat-
tened and narrow, the sutures being less strongly m.arked ; the latter two or three volu-
tions in adult specimens are more inflated, and they acquire at the base a rudimentary
umbilical groove.

It is nearly allied to Fibula nudiforniis, Piette ('Bull, de la Soc. Geol. Pr.,' 1857,
pi. 6, figs. 4, 5), from the Great Oolite of Rumigny, Eparcy, Poix, But, &c. ; but, judging
from the figures of M. Piette, his species has a shorter spire, with less strongly impressed
sutures, and the last two volutions are more lengthened and cylindrical. Fibula =
Chemnitsia jjJtasicmoides, which has the spine similarly subulate, has the volutions more
flattened, and the sutures much less impressed ; other recognised species are more
lengthened, with flattened volutions.

Geohfjical Position and Localities. Fibula variata has occurred rarely in the Great
Oolite of Minchinhampton, and more commonly in the same formation at Kirklino-ton,
Oxon., from which place Mr. Whiteaves has kindly forwarded specimens. Examples are
deposited in the British Museum, the Woodvvardian ]Museum, Cambridge, in the collection
of Mr. Whiteaves, of Oxford, and in that of the author at Scarborouorh.

PiBULA EULiMOiDES, Whiteaves, sp. Tab. XXXI, fig. .5.
Chemnitzia EULIMOIDES, WMteaves. MSS., 1859.

Testa turriculata, elongata, spira apice acuta, anfractibus {circa 12) angustis, convexis
superne vitta cingenda, suturis valde constrictis, ultimo anfracfu rotundo ; aperturd obliqud,
basi angusfo subsiimato, columella umbilico rudimento ; labro externa arcuato ; anfractibus
cosfis obliquis obscuris irregularibus.

Shell turreted, elongated, acute ; spire with about 12 volutions, narrow, convex towards
their lower parts, and encircled with a narrow band at their upper borders ; the sutures
are deeply impressed ; the last volution moderately large and rounded ; the aperture is
lengthened, oblique, narrow, and sinuated at the base ; there is also a rudimentary um-
bilical groove ; the outer lip is much arched ; the surface has irregular, oblique, obscure
costa;, which resemble lines of growth in the latter volutions.

Compared with Fibula variata, this species is more subulate, with a shorter last volu-
tion ; the encircling band upon the upper border of each volution, the oblique costae, and
the convexity of the lower part of each volution, are also distinguishing features. Fibula
undulosa, Piette, is more nearly allied to it, but the volutions are less narrow and more
flattened or destitute of the swelling of the lower portions of the volutions which is a
conspicuous feature in F. eulimoides. The height of each volution is equal to half of its
opposite diameter.

3

18 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Geological Fosition and Locality. The Great Oolite of Stonesfield, collected by Mr.
Whiteaves.

RissoiNA WiTCHELLi, Lyc. Tab. XLIV, fig. 12.

Testa elongato-turrita, anfractibus 6, latis, convexis, aut medio avyulatis, Jongitudinaliter
costellatis, cosfelHs circa 26 — 28, rectis, simplicihus, crebris ; aperfura ovafo-obliqua, labro
extus incrassato.

Shell elongately turreted ; volutions 6, wide, convex, angulated at their middle part,
and encircled with a slender band at the mesial angle ; the longitudinal little ribs are very
closely arranged ; they are smooth, narrow, perpendicular, and are united to the mesial
band ; from 26 to 28 in a volution ; the last volution is conformable with the others, both
in figure and ornamentation ; the aperture is of moderate size, it is oblique, ovate, but
rather pointed at the two extremities ; the columella is curved in its middle ; the outer lip
is thickened.

The angulated figure approximates to Bissoina duplicata. Sow., sp., ' Gr. Ool. Mon.,'
i, p. 52) ; but the last volution is somewhat less expanded, the costse upon the spire are
less conspicuous, and nearly three times as numerous. Mr. Witchell, who discovered the
species, has kindly communicated several specimens whicli agree with each other in all
essential particulars.

Geological Position and Locality. The Great Oolite of Minchinhampton Common,
associated with other minute testacea.

RissoiNA MiLLERi, Lyc. Tab. XLIV, fig. 10.

Testa turrita subcylindrica, anfractibus (6) siibconvexis, angmtis, longitudinaliter costel-
latis ; costellis 17 — 18, rectis simplicibus ; apertura ovato-semihinari, ad basim effiisa ;
labro extus valde incrassato.

Shell turreted, subcylindrical ; volutions (6) convex in tbeir middle part, narrow, but
with the sutures only slightly impressed ; longitudinally costellated; costellge 17 — 18, per-
pendicular, not very prominent, and plain ; aperture ovately semilunar, oblique, expanded
at the base, the outer lip having a considerable thickening.

Allied to Bissoina acuta, Sow., but having the volutions more narrow and less con-
vex, the sutures being less deeply impressed ; the little ribs are much more numerous;
the aperture is also larger and more effuse at the base.

Geological Position and Locality. One of a series of minute univalves obtained by
Mr. Whiteaves in the Great Oolite of Minchmhampton Common. The name is an
acknowledgment of the discrimination of the author of ' The Natural History of the Crin-
uoidea,' who appears to have been the first person to discover the fossil riches of this locality.

GASTEROPODA. 19

and whose strongly expressed opinion was originally the means of directing the attention
of the present writer to it.

Amberleya nodosa, Tab. XLI, fig. 3 ; et Part I, PI. V, fig. 19, 1850.

This elegant shell was represented in so defective a manner at Plate V, fig. 19, as to
render it desirable to give the present illustration, in wliich the aperture faces the spectator
more directly. The examination of additional specimens has tended to confirm the views
expressed in my manuscript of 1850, viz., that Amberleya should rank as a distinct genus
of the LittorinidcB, separated from Littorina by the thin test, lengthened, almost turricu-
lated, spire, and scarcely less so by the ornamentation of the volutions. Other examples
of Amherleya will be found in A. Jurassi, Lye. (the next species here described), Turbo
cajntaneus, Munst., Turbo ornatus, Sow., and some other allied Inferior Oolite species
which have been figured by D'Orbigny as examples of Furpurina, but which are well
distinguished from the type form of that genus (see the observations on Pur^mroidea
insignii). The generic appellation Amberleya was derived from Amberley Heath, which
is a second name for Minchinhampton Common.^

Amberleya Jurassi, Lye. Part 1, Tab. IX, figs. 33, 33 a.

Testa turbinato-conicd, acuta, lineatd, anfractibus (6) latis, tricarinatis, carina mediana,
magna, subacula, anfractu ultimo carinis 8, elevatis, subacutis, striis obliquis serratis, aper-
tura magna, ovafa basi subangulato, columella recta.

Shell turbinated or conical ; spire elevated, acute ; volutions (6") high, with three
elevated, subacute carinas, of which the median carina is the most prominent. The last
volution is large, with eight elevated carinse, their edges being serrated by oblique, longi-
tudinal striations ; the aperture is large, ovate, somewhat angulated at the basal junction
with the columella, which is straight.

Distinguished from Turbo capitaneus, Goldf., both by the characters of the general

1 Subsequently to the completion of this Supplement, I have been favoured by M. Eugene E.
Deslongchanips with a copy of his memoir, extracted from the fifth volume of the ' Bulletin of the Linnean
Society of Normandy,' 1860, entitled " Observations eoncernant quelques Gasteropodes, Fossiles, des
Terrains Jurassiques places par Vauteur de la 'Paleontologie Fraraise' dans les genres Purpnrina. Trochus
et Turbo. Note sur le genre Eucyclus." The latter proposed new genua is identical with our Amberleya.
quoted in the memoir ks Abberleya. The author has in this little work given an excellent critical analysis of
the group of wliich he has proposed to constitute Eucyclus ; these are Purpurina Patroclus, D'Orb.,
P. Philiasus, D'Orb., P. ornata, D'Orb., P. bathis, D'Orb., Turbo Itys, D'Orb., T. ulceus, D'Orb,, T.
Julia, D'Orl)., T. capitaneus, Munst., T. castor, Roem., T. princeps, Roem. He has also figured and de-
scribed the following new species — Eucyclus obeliscus and E. jxipyraceiis, from the Upper Lias ; E. pinguis
and E. go?iiatus, from the Inferior Oolite ; the latter shell, in its general figure and plan of ornamentation
has a considerable resemblance to Amberleya nodosa. Eucyclus is tlierefore a synonym of Amberleya.

20 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

figure, by the greater number of caringe, and by the absence of tubercles upon them.
Turho castor, D'Orbigny, resembles it in the characters of the carinae, but they are less
numerous and less elevated ; the spire is also much less produced.

Height 15 lines, transverse diameter of the last volution 11 lines.

Geological Position and Locality. The Great Oolite of Minchinhampton Common, in
which it occurs rarely in the coarse volite or planking.

Amberleya armigeka, Lye. Tab. XXXI, fig. 6.

Testa conica spira elata, apice acuta, anfractibus (5) convexis, subangulatis, costis
tuberculosis cinyendis ; costis duobus superioribus minoribus, inferioribus majoribus ; anfractu
ultimo basi carinis serratis (5) cinyendis ; umbilico nullo.

Shell conical ; spire elevated, pointed ; volutions (.5) convex, somewhat angulated, with
four encircling costae or carinse, which are densely and delicately tuherculated, and
decussated by fine striations, tlie two lower costae being much larger than the upper, so
that the lowest costa overhangs the upper part of the next volution ; the base has five
encircling, serrated costae ; there is no umbilicus.

Height 10 lines, length of the last volution S lines.

The encircling carinae occupy nearly the entire height of each volution, leaving only
narrow, deep, interstitial spaces ; the lowest of the carinae is the largest. The general
figure approaches to Turbo capitaneus, Goldf., but the latter has the encircling carinae much
more elevated, narrow, more widely separated, and less numerous. Tarbo Phillipsi, Mor.
and Lye, has a much shorter spire, with the volutions less ventricose or angulated ; other
species are more remotely allied.

Geoloyicnl Position and Locality. — The Cornbrash of Scarborough, in which it is rare;
from the cabinet of John Leckenby, Esq.

Nerita involuta, Lye. Tab. XXXI, fig. 15.

Testa oblique ovata, laviyata, spira parva, depressa, sub-celata, anfractu uUi»io per
injlato ; apertura umpla, labro inferno convexo.

Shell oblique, ovate, smooth ; spire (apparently consisting of two volutions) small,
depressed, nearly concealed by the envelopment of the last volution, which is much inflated
at the aperture ; inner lip convex, smooth.

A plain species, distinguished by the great length and volume of the last volution ; the
apex of the spire is imperfect, but though quite depressed, probably it is not altogether
concealed ; the general figure is allied to Nerilina Staffensis, Forbes, but the latter is
more lengthened and more minute.

Geoloyical Position and Locality. Collected by Mr. Whiteaves in the Great Oolite of
Kirklington, Oxon.

GASTEROPODA. 21

Neritopsis Archiaci, D'Arch., sp. Tab. XXXI, fig. 7, 7 a.

TuEBO CANALicuLATUs, D' Archiac. Mem. Soc. Geol. Fr., vol. v, pi. 29, fig. 6.
— Archiaci, B'Orbigny. Prodr., i, p. 300.

Testa ovafo-depressa, spira elata, anfractibus tribus vel quarfernis, angustis, inflatis,
siifvris profimde canaliculatis, anfractii ultimo costis fransversis obscuris, inaqualibus,
inegularibus, striisqiie crebris decussatis ; striis tenuibus, reyularibm, undatis ; apertura
ampla, suborbiculari.

Shell ovate, depressed; spire elevated, consisting of three or four volutions, which are
narrow, inflated, their sutures deeply channeled ; the last volution has some obscurely
marked, irregular, and unequal transverse costa decussated by encircling striations ; the
striations are regular, very closely arranged, faintly impressed, with small, wave-like
undulations ; the aperture is large and rounded.

More depressed than N. sulcosa and N. striata, but with larger volutions, the sutures
being also more deeply channeled ; the ornamentation of the surface is so faintly impressed
that it is scarcely perceptible without the aid of a magnifier.

Geological Positions and Localities. A rare species, from the Cornbrash of Scar-
borough, in the collection of Mr. Leckenby. Eparcy, France.

Trochus Gcisei, Lgc. Tab. XLV, fig. 14.

Testa alta conica, apice acuta, anfractibus (6) latis, leviter concavis, anfractu ultimo
subangulatd, basi convexo, concentrice striata ; anfractibus, costis obscuris, obliquis, ad basin
bi-cinctis ; apertura depressa.

Shell elevated, conical ; volutions (6) wide, apex acute, slightly concave in their middle
portions ; the last volution angulated ; the base convex, with fine, encircling striations ;
the sides of the volutions have delicate, obscure, obhque costse, which are interrupted
towards the base of each volution by two narrow, encircling bands ; the sutures are
delicate and faintly marked ; the aperture is depressed.

The ornamentation of this little Trochus is regular and but faintly sculptured ; the
encircling bands are rendered slightly nodular by the decussating costae.

The name in compliment to W. V. Guise, Esq., President of the Cotteswold Naturalists
Club.

Geological Position and Locality. The Great Oolite of Minchinhampton, collected by
E. Witchell, Esq.

22 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

MoNODONTA ExiGUA, Lyc. Tab. XLIV, fig. 29.

Testa jjarva ovata, spira elafa, obtiisa, anfractibus fribus, subplanis, anfractu ultimo
rotundo ; striis tenuibus cingendis, costisque obliquis depressis, crebris, decussatis ; apertura
ovata, columella ad basin incrassato, mbmnbilicato.

Shell small, ovate ; spire elevated, obtuse; volutions three, very slightly convex, the
sutures distinctly marked ; the last volution rounded with densely arranged, delicate,
encircling striations, which are decussated upon the upper and middle portions of the
volution by numerous depressed, oblique costae, which are rendered somewhat granular by
the striations ; the aperture is ovate, the columella is thickened at its base, and there is a
slight umbilical depression ; the base of the last volution is destitute of costae.

Geological Position and Locality. The Great Oolite of Minchinhampton Common,
collected by Mr. Witchell.

MoNODONTA Ltcetti, Wliitcaves, MSS. Tab. XXXI, figs. 14, 14 «.

Testa subdepressa, spira brevi, exserta ; anfractu ultimo permagno lateribus planatis,
costisque magnis, crenulatis, cingendis, basi constricta sulcb r.iagno.

Shell depressed ; spire short and slightly mamraillated, the last volution very large,
angulated at its upper margin, flattened upon its sides, and slightly convex towards the
base, which has a large, encircling furrow ; the aperture is moderately large, wide above,
contracted towards the base ; the columella is rounded and very tumid.

The whole shell is encircled with rows of rope-like crenulated costse, the upper border
and flattened sides being formed by three costse larger than the others ; beneath these are
five costaj diminishing symmetrically to the basal furrrow ; the upper surface, which is
flattened, has three encircling costse, within which rises a small, mammillated apex.

Lateral diameter one fourth greater than the height.

The large, rounded costse, flattened sides, and depressed figure, readily distinguish
it from allied species.

Geological Position and Locality. In soft, pale, gray, marly limestone (Bradford
Clay?), Islip, Oxon., collected by J. F. Whiteaves, Esq.

MoNODONTA SPARSISTRIATA, Lyc. Tab. XLV, fig. 9.

Testa parva turbinata, depressa, spira anfractibus 4 ; covewiusculis, striis 6, cingendis ;
apertura ovata, bast mbp)lan6, lavigato, timbilico mdlo.

Shell small, turbinated, depressed ; spire moderately elevated, consisting of four rather

GASTEROPODA. 23

convex volutions, which are encircled with six regular striations ; the aperture is ovate, the
base somewhat flattened and smooth ; there is no umbilical depression.

A small shell, with the last volution expanded and depressed ; the striations are rendered
slightly scabrous by very delicate, obtuse, decussating ornamentation, partially preserved,
and which is only visible under a considerable magnifying power.

Geological Position and Localiti/. The Great Oolite of Minchinhampton Common,
collected by Mr. Witchell.

MONODONTA COMPOSITA, LtjC. Tab. XLV, fig. 6.

Testa parva subdepressa, sjnra anfractibus 3 — 4 angustis, angulatis, superne concavis ;
lineis angustis, regularibus subdistantibus cingendis, anfractu ultimo permagno, superne
costulis depressis longitudinalibus lineis decussatis ; aperturd magna ovatd, columella
solida, dentata.

Shell small, rather depressed; spire with the volutions (3 — 4), angidated in their
middle part, narrow, delicate, and rather distantly arranged, the last volution is very large ;
the surface above the mesial keel is concave, and has closely arranged, depressed, longitu-
dinal, little elevations or ribs, which are rendered nodulous in their upper parts by the
encircling lines ; the aperture is moderately large ; the columella has a conspicuous
thickening at its base; there is also a slight umbilical depression.

Geological Position and Localitg. The Great Oolite of Minchinhampton Common,
collected by Mr. Witchell.

SoLAEiuM Bathonicum, Lgc. Tab. XLV, figs. 27, 27 a, 27 b, 27 c.

Testa parva depressa, superne planata, inferne concav6,concentrice striata ; anfractibus
(3) angustis tabulatis, externe subcarinatis nodulisque paucis, obscuris, coronatis ; lateribus
subconvexis striatis.

Shell small, depressed, flattened above, concave beneath and concentrically striated ;
volutions (3) narrow, tabulated, externally slightly carinated, and with a few obscure
coronary tubercles ; the upper and lateral surfaces have encircling striations, the sides
being slightly convex.

The specimen examined has a diameter of only two lines, the height being equal to
about one third of the breadth.

Geological Position and Localitg. The upper beds of the Great Oolite in the vicinity
of Bath, collected by Charles Moore, Esq.

24 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Pleurotomaria granulata, Soil)., sp. Tab. XXXI, fig. 8, 8 a.

Trochus granulatus, Soiu. Min. Con., t. 220, fig. 2.

Pleurotomaria granulata, Beslong. Mem. Soc. Linn., viii, pi. 16, figs. 6 — 8.

— — VOrb. Prodrome, p. 267.

— — Morris. Cat. Brit. Foss., 1854, p. 2/1.

— — Quenstedt. Der Jura, p. 41-4, tab. .57, figs. 5 — 7.

Tesla trochiformi subturrita, apice acuta, anfractibiis convexiiisculis, in medio angulatis,
suhgradatis, superne planiusculis, inferne convexiusculis, transverse et longitudinaliter
striatis ; sinu angusto, fascia sinus prominente, transverse tenuissime striata, in medio
anfractumn sita ; ultimo anfractu ad basin subangulato, basi subconvexa, concentrice striata ;
umbilico minimo out subnullo ; apertura siibquadrafa labro sinistra crassiari rejlecto.

Shell trochiform, subturreted ; apex acute; volutions rather convex, angulated in their
middle portions, or somewhat step-like, the upper half of each volution being flattened, the
lower half rather convex ; the surface is longitudinally and transversely striated, the decus-
sations of the striae forming granules or tubercles, of which there are usually five rows
above and four beneath the mesial angle, the uppermost row having the tubercles more
prominent and separated than the others; the sinus is narrow, and of moderate depth;
the fascia of the sinus is prominent, with fine, transverse striations, and placed in the
middle of the volution ; the last volution has the base somewhat angulated ; the base is
convex, and concentrically striated ; the umbilicus is very small or almost none ; the
aperture is subquadrate, the left lip being thickened and reflected.

A beautiful species, not very regular in the disposition of the longitudinal and transverse
striations, but for the most part those beneath the mesial fascia are more strongly marked
than above.

The height of the entire shell and diameter of the last volution are equal in the
specimen figured ; others have the height somewhat greater ; 16 lines is a medium size.

Geological Positions and Localities. The Inferior Oolite of the south-west of England
and the Cornbrash of the coast of Yorkshire. Our specimen is from Gristhorpe, in the
collection of ^Ir. Leckenby. It is moderately abundant.

Cylindrites exigua, Lgc. Tab. XLIV, fig. 14.

Testa parva, subcglindricd, spira elata conica, apice obtiiso, anfractibus 5, latis, patdu-
lum canvexis, spira vera lateribus subcoticavis ; anfractu ultimo margine rotundato, aper-
tura angustissimo.

Shell minute, subcylindrical ; spire elevated, conical, its sides being, however, slightly
concave, and its apex obtuse ; the volutions are five in number, moderately wide and

GASTEROPODA. 25

slightly convex ; the last volution is lengthened, its upper margin is rounded ; the aperture
is very narrow.

More lengthened and attenuated, the spire more elevated, and its apex more obtuse,
than in C. acutus, to which species it appears to be most nearly allied.

Geological Position and Locality. The Great Oolite of Minchinharapton, collected by
E. Witchell, Esq.

Ctlindrites turriculatus. Tab. XLIV, figs. 26, 26 a.

Cylindrites turriculatus, Lycett. Proc. Geol. Soc, 1853, p. 342, vol. ix, pi. 14,

fig. 8.

Testa elongatd, subylindricd ; spird magnet, acutd ; anfractihus (8) convexis ; suturis
prqfunde impressis ; anfratu ultimo ovato ; apertura angustata.

Shell elongated, ovately cylindrical ; spire lengthened, its apex acute ; volutions (8 in
the adult state) convex, their sutures deeply impressed, the last volution ovately cylindrical ;
aperture narrow.

The general figure somewhat resembles C. altus, but the volutions are more numerous,
and are not flattened, as in that shell ; the subovate figure and elevated spire readily distin-
guishes it from other contemporaneous species. The length of the aperture is equal to
three fifths of the entire shell.

Geological Position and Localities. Eormerly collected at Ponton, Lincolnshire, by
Professor Morris ; recently it has been obtained in the Great Oolite of Minchinhampton
by E. Witchell, Esq.

AcTEON Bathonicum, Lyc. Tab. XLIV, fig. 16.

Testa parva ovafa, spira elevata, anfractibus (4) subplanis, ad siituravi angulatis, supra
angwlam spiratis, tabula fis, ultimo anfractit striis regularibus tenuibus ; apertura ovali,
postice angustatd.

Shell small, ovate, spire elevated, volutions (4) rather fiattened upon the sides and ele-
vated, their superior borders forming a sharply defined angle ; above the angle is a flattened
sutural area, the last volution has regular, delicate, encircling striations ; the aperture is
moderately large, ovate ; the posterior extremity narrow ; its length is more than half the
height of the shell.

A minute hut well-marked species, with a spire larger, more lengthened, more angulated
and more pyramidal than Auricula Sedgvici, Phil. ; it is more nearly allied to Tornatella
Aviotkensis, Buv., 'Pal., Mense,' pi. xxiii, figs. 32, 38 ; and to Tornatella pulla, Kock and
Dunk., 'Ool.,' pi. xi, fig. 11; but these have the spire more lengthened and less
flattened.

Geological Position and Locality. One of a series of minute and, for the most part,

4

26 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

dwarfed testacea, collected by Mr. Moore from the upper portion of the Great Oolite in
the vicinity of Bath.

ACTEON PHASIANOIDES, Lijc. Tab. XLIV, fig. 28.

Testa parva ovafo-elonffafa, subJceve, sjnra alta, furrieulafa afracfibus 5, superne con-
vexi-s, in/erne planatis, anfracfu ultimo mar/no, ovato, basi tenerrime striata, apertura
eUtptia, columella recta, uniplicatd.

Shell small, ovately elongated, nearly smooth ; spire elevated, turreted ; volutions 5,
convex above, the sides flattened, and the sutures strongly defined ; the last volution
slightly exceeds half the entire length of the shell ; it is ovate, its base having some delicate,
regular spiral striations ; the aperture is elliptical, the columella straight, having a single
plication.

Possibly the entire surface may have had striations still more delicate than those at the
base, but no traces of them remain ; the spire is larger, and the volutions are more infiated,
than is usually seen in this genus.

Geological Position and Locality. The Great Oolite of Minchinhampton, collected by
E. Witcliell, Esq.

ACTEONINA BREVIS. Tab. XLI, fig. 6.

Under the title of Cylindrites brevis, an immature and imperfect example was figured
in the first part of the 'Great Oolite,' Monograph. Tab. VIII, figs. 13, 13, a; the fine
example now figured was collected by Mr. Whiteaves in the Great Oolite of Kirklington,
Oxon., and exhibits in the more advanced stage of growth a change in the last volution,
whose upper margin rises higher than those of the preceding volutions, thus rendering the
vertex slightly concave, a change with which recent conchology presents many analogous
instances. The figure of the columella leaves no doubt that it is an Acteonina.

ACTEONINA KiKKLINGTONENSIS, Lt/C. Tab. XLI, fig. 5.

Testa ovato-cylindrica, elongafa, laviyata, spira obtusa, perspicua, anfractibus (4)
depressis, columella ad basin cortorta, apertura inferne elongata, ovata.

Shell ovately cylindrical, elongated, smooth ; spire obtuse, depressed, the upper margins
of the volutions exposed and rounded ; columella contorted at its base, forming with inner
lip an umbilical depression ; aperture narrow above, pyriform, lengthened, and rather
pointed at its base.

A lengthened cyhndrical Acteonina, with an exposed, obtuse spire, which does not rise
higher than the upper border of the last volution ; a small specimen is, in proportion.

GASTEROPODA. 27

somewhat shorter. It is nearly allied to Bulla ? primcBva, Deslongchamps, ' Mem. Soc.
Linn, de Normand.' t. 7., pi. x, figs. 23, 24 ; the latter is a larger shell, with the spire less
exposed, and the aperture at the base much less lengthened and less pointed ; it is there-
fore probably distinct. The elongation of the anterior part of the aperture appears also to
separate it from Acteonina convoIiita,'Lyc., ' Cotteswold Hills,' p. 125, the left-hand figure,
pi. iv. As three specimens of each form of different states of growth have been examined,
we may rely upon the persistence of this distinctive feature.

Length 11 lines, opposite diameter 6 lines.

Geological Position and Locality. The Great Oolite of Kirklington, Oxon., collected by
Mr. Whiteaves, who has obtained several specimens.

Acteonina Luidii, Luid., sp. Tab. XXXI, fig. 16. ; Tab. XLI, fig. 18, a, b, c.

CocHLiTEs LuiD. Lithoph. Brit. Ichnogr., 1699, 417.
AcTiEONiNA Luidii, Mor. Cat. Brit. Foss., 1854, p. 234.

Testa suhcylindrica, antice mediocriter attenuato, postice truncato, anfractii ultimo
superne angulato, laterihus planatis, spira depressa, anfractibus (4 — 5) anyustis, apice
exserto.

Shell short, subcylindrical, moderately attenuated anteriorly, truncated abruptly poste-
riorly ; volutions (4 — 5) depressed, narrow, their upper margins exposed upon the flattened
posterior surface ; the apex is slightly elevated and obtuse ; the last volution has its posterior
margin angulated and its sides flattened. Casts exhibit the upper margin of the last
volution somewhat rounded, and also the edges of the other volutions.

Height one third greater than the transverse diameter.

Geological Position and Localities. The Forest Marble of Kidlington, Oxon., collected
by Mr. Whiteaves, and of Cirencester, Gloucestershire, collected by myself, at both of
which localities it is rare.

Acteonina canaliculata. Lye. Tab. XXXI, figs. 9, 9 a, 9 b.

Testa subcylindrica laevigata vel ovata, sjnra exserta, obtusa, anfractibus (7) angustis,
subplanis, superne convexis, et canaliculcitis, ultimo anfractu subcyUndrico, basi . . . . ?

Shell subcylindrical, smooth, or ovate ; spire elevated, obtuse, consisting of 7 narrow volu-
tions, which have their sides flattened, their upper borders being rounded and deeply
channeled ; the last volution is nearly cylindrical, the aperture is not exposed, and the base
is imperfect.

The characters of the spire, with its numerous narrow-channeled volutions, without
angularity, appears to be sufficient to distinguish the species.

Geoloyical Position and Locality. The Great Oolite of Kirklington, Oxon., obtained
by Mr. Whiteaves.

28 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

ACTEONINA SCARBTJRGENSIS, Lyc. Tab. XXXI, figs. 13, 13 (7.

Testa ovata ventricosa Icevigata, spira brevi obtusa, anfractibus (4) convexis, anfracfu
ultimo ad suttiram subcanaliculato ; apertura angustata, columella ad basin marginata.

Shell ovately ventricose, smooth ; spire short, obtuse, consisting of four narrow, convex
volutions ; the last volution has the sides shghtly convex, its upper margin rounded and
slightly channeled at the suture ; the aperture is narrow, somewhat expanded at the base,
which is marginated at its junction with the columella.

A handsome ventricose shell, shorter and more tumid than A. convoluta, Lyc, which
appears to approximate more nearly to it than other recognised species.

Length 14 lines, diameter of the last volution 10 lines, length of the aperture 11 lines.
The specimen figured is from the fine collection of Mr. Leckenby ; the test, which is thin, is
partially preserved ; it has a corneous aspect. A single specimen.

Geological Position and Locality. The Cornbrash of Scarborough.

AcTEONiNA scALARis, Lyc. Tab. XLIV, fig. 18.

Testa parva, subcylindracea, spira brevi, acuta, anfractibus \,latenbus angustis planatis,'
marginibus acutis, superne tabulatis ; apertura elongatd, basi elliptico curvato.

Shell small, subcylindrical ; spire short, but elevated and acute, consisting of four
narrow volutions, which are flattened upon their sides, their upper borders are acute, their
upper areas are flattened ; the aperture is moderately large and lengthened, its base is
elliptically curved.

The length is 3 lines, the opposite diameter but little exceeds 1 line.

The upper angle of each volution is acute, and even slightly projects outwards, a
character which is not seen in any other known species with an elevated spire. Possibly
this is the young condition of a much larger species.

Geological Position and Locality. The Great Oolite of Kirklington, Oxon., collected
by Mr. Whiteaves. ^

Dentalium entaloides, Desl. Tab. XXXI, figs. 11, 11 «, Vlb,

Dentalium , Phillips. Geol. York., i, pi. 4, fig. 37.

GLABELLUM, Dean. Cornbrash Fossils, Mag. Nat. Hist., 1839, without

figure or description.

— ENTALOIDES, Deslongchamps. 1842. Mem. Soc. Linn., vii, p. 128, tab. ?ii,

figs. 36—38.
_ _ B'Orb. Prodrome, i, p. 272, No. 205.

— Pabkinsoni, Quenstedt. Handbook, t. 35, fig. 19.

GASTEROPODA. 29

Dentalium Parkinsoni, Quenst. Der Jura, p. 484, t. 65, figs. 5, 6.

— ENTAL0IDE3, Oppel. Die Juraformation, 1856-8, p. 390.

— ANNCLATUM, Bean, Leekenby. Journ. Geol. Soc, 1858, vol. iv.

Testa crassa, tereti, subarcuata, scejnus nitida, striis tenuissimis densissimis paululim
obliquis ornata. (Deslongchamps.)

Shell thick, tubular, round, smooth, shining, slightly curved ; encircled with striations,
which are somewhat oblique and strongly impressed towards the posterior or smaller
extremity, anteriorly they are more faintly and densely arranged and ultimately disappear,
the surface having some irregular annular folds of growth. Length of an imperfect Corn-
brash specimen 24 lines, the larger diameter 2^ lines. The Calcareous Grit examples have
larger dimensions, they are of more advanced growth, and have the greater portion of their
cylinder devoid of striations.

The Cornbrash imperfect specimens are less slender and more straight than the figures
of B. Parkinsoni given by Professor Quenstedt, and more nearly accord with those of
D. entaloides, Deslongchamps ; but the specimens figured by Quenstedt differ also from
each other in their attenuation and curvature. Dentalium cinctum, Goldfuss, has encirclins
striations, without obliquity ; D. undulatum of the same author has the figure some-
what compressed ; D. tenue, Goldf , is more slender and more nearly cylindrical.

Geological Position and Locality. Dentalium entaloides appears to have a considerable
geological range; the Cornbrash of Scarborough has produced a few specimens; Mr.
Leekenby has also obtained it in the Kelloway Rock and the Calcareous grit of the same
locality. D. entaloides was obtained by M. Deslongchamps in the Inferior Oolite of
Moutiers and Bayeaux ; by Dr. Oppel in the beds with Ammonites Parkinsoni at Mont
d'Or, near Lyons; in Swabia it occurs at the upper boundary of the Lower Oolite (Braun
Jura e. Quenst.) at Ehningen and Balingen.

Trochus strigosus, Li/c. Tab. XLV, fig. 12.

Testa alta, conica, transverse costellata, costellis granulosis cequalibus ; anfractibus (5)
sub2)lanis, quadricostatis et vitta striata anteriora ; ultimo anfractu obtuse carinatd ; basi
concava ; columella obliqua ; apertura sub-trian(/ulari.

Shell elevated, conical, transversely costellated ; costellae, four to a volution, granulated
and equal ; the anterior border of each volution has also a depressed, striated band ; the
volutions, about five in number, are flattened, and the last volution is rounded ; the base
has a few striations ; the columella is oblique, and the aperture somewhat triangular.

The ornamentation is strongly marked and regular ; the height and breadth are nearly
equal ; the sole specimen is rather imperfect at the apex.

Geological Position and Locality. The Cornbrash of Gristhorp Bay, near Scar-
borough, in the collection of Mr. Leekenby.

30 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

BIVALVIA.

Gryph^ea minuta, Sow. Tab. XL, fig. 30.

GRYPH.SA MINUTA, Sowerby. Min. Con., tab. 547, fig. 4.
— — Morris. Catal. Brit. Foss., p. 186.

Testa parva, valva majora suborbieulata, uinboni incurvo, latere antico sidco brevi
instrucfo. Valva altera ignota.

Shell small ; the larger valve subglobose, suborbicular ; the beak produced, incurved,
and nearly straight, only slightly roughened by the area of attachment ; the anterior side
with a short sulcation, but no distinct lateral lobe. The smaller valve is unknown.

A minute Gryphaea, of which several specimens have been obtained by Mr. Witchell
in the Minchinhampton Great Oolite ; it has no well-defined distinctive features, and
would scarcely have been deemed worthy of notice had it not been figured by Mr. Sowerby
from Ancliff.

Placunopsis semistriatus, Bean, sp. Tab. XXXIII, figs. 9, 9 a.

Anomia semistkiata, Bean. Mag. Nat. Hist., 1839, p. 61, fig. 21.

Testa, valva majora convexa, subobliqua, ovato rotundata, apice submarginali, acuta,
lamellis concentricis, irregularibus, superne Icevigata, in/erne lineis radianiibus subaqualibus
nodulosis ornata. Valva affixa ignota.

Shell with the larger valve ovate, slightly oblique, convex; the apex pointed, and
placed near to the margin ; the surface has numerous irregular, concentric lamellae ; the
lower portion has numerous radiating lines, which ai"e nearly equal, granulated, and
undulated. The attached valve has not been obtained.

The test appears to be less delicate than is found in some other examples of the genus,
and is usually affixed to another shell, more especially to Terebratida lagenalis, so that it
is scarcely possible to obtain a specimen whose figure has not been affected by some
extraneous body. The general aspect has much resemblance to Placunopsis Jurensis
(' Gr. Ool. Monog. Biv.,' tab. i, fig. 13), but the latter has the ornamentation of the
surface much more strongly defined, with larger and more densely arranged radiating lines.
In P. semistriatus these can only be discerned with a magnifier.

Geological Position and Locality. The Cornbrash of the Yorkshire Coast, at Gris-
thorpe and Scarborough, where it is moderately rare. The upper portion of the
Inferior Oolite in the Cotteswold Hills has a species probably identical with this Pla-
cunopsis, and possessing a similar kind of ornamentation.

BIVALVIA. 31

Pecten rigidus, Sow. Tab. XL, fig. 16.

Pecten rigidus. Sow. Min. Con., t. 205, fig. 8.

— — Morris. Catal, 1854, p. 177.

— — D'Orb. Prodr. Et., xi, p. 314.

— — Oppel. Juraforraation, p. 492.

Tesfa ovafo-orbiculari, sub-cequivalvi, plaiio-convexa, reticulata, costis depressis, crehis,
mh-regidarihus, divergentihus, lameUis concentricis angusfis, hinc hide decmsatis ; auri-
culis i)i(Equalibus, transverse lamellosis, lameUis elevatis, crebris.

Shell ovately orbicular, equivalve or subequivalve, moderately convex ; costae diverging,
depressed, slightly unequal, sometimes undulating and closely arranged, crossed by narrow,
irregular, concentric lamellae, which are sometimes elevated upon the ribs, and in other
instances form only narrow lines across the interstitial spaces, giving to them a punctated
aspect ; auricles large, unequal, with numerous transverse, narrow, elevated lamella?.

Geological Positions and Localities. It is not uncommon in the upper portion of the
Great Oolite, in the Forest Marble, and in the Cornbrash of many localities, as at Castle
Combe ; Stanton, near Chippenham ; Kidhngton, Oxon. ; Rushden, Northamptonshire ;
Luc, France.

PfiCTEN Griesbachi, Lyc. Tab. XXXIII, figs. 6, 6 a.

Testa, valva sinistra crassa subceqtiHaterali acuta, compressd, auriculis magnis sub-
aqualibus, radiatim costata et concenfrice striata, costis {circa 26) superne angustis sub-
(equalibiis transverse striatis, in/erne obsoletis ; striis concentricis, regularibus tenuissimis ;
auriculis transverse plicatis. Valva altera compressa interne lavigata.

Shell with the left valve thick, subequilateral, compressed, acute ; auricles large, nearly
equal, and transversely plicated ; the surface is ornamented with about twenty-six very
delicate, radiating costa3, which are striated, narrow, nearly equal, and regular ; they are
distinct towards the apex, but are only faintly traced towards the middle and lower part
of the valve ; the concentric striations are very fine and regular over the whole surface ;
a few faintly marked plications of growth are visible towards the lower border. The
external surface of the right valve has not been exposed ; its convexity is about equal to
that of the other, its inner surface being smooth, without traces of the exterior orna-
mentation.

Geological Position and Locality. The Great Oolite of Wollaston, Northampton-
shire, in the cabinet of the Eev. A. W. Griesbach.

32 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Pectex in^quicostatus, Phil. Tab. XXXIII, figs. \,\a.

Pecten IN^QTJICOSTATUS, Fhil. Geol. York., i, pi. 4, fig. 10.

— — jyOrh. Prodrome, p. 373.

— ocTocosTATUS, Roemer. Ool., p. 69, pi. 3, fig. 18.

— iN^QUicosTATUS, MoT. Cat. Brit. Foss., 1854, p. 176.

— — Oppel. Juraformation, p. 607.

Tesfa ovato-acuta, convexa, longitudinaliter, 8 costata, concenfrice lineafa, costis con-
vewis latis sulcis conformibus in dorso hinc hide dentatis, duobus mediis latioribus, lineis
exilibus confertis sublamellosis auriculis subaqualibus longitudinaJiter lineatis. [Roemer pro
valva dextra.) Valva sinistra costis (8) anc/ustis, elevatis rotundis asymmetricis, subnodosis,
interstiis latis irrer/ulariter concentrice sfriatis.

A convex, subaequivalve, acute-pointed Pecten, with large, nearly equal auricles ; the
surfaces of both the valves having irregular, concentric striations and several large folds of
growth. The right valve has broad, slightly elevated costse (8), which are unequal and
slightly defined towards the posterior side, separated by narrow and but little depressed
sulcations, which are distinct upon the inner surface of the valve ; the left valve has eight
narrcw, elevated, but rounded costge, of which those upon the sides are small and
unsyiiimetrical ; the intervening spaces are broad upon the middle of the valve, and very
narrow laterally ; the auricles are obliquely lineated.

Geological Positions and Localities. Rarely in the Cornbrash and Kelloway Rock of
Scarborough, more commonly in the Coralline Oolite of Malton, but it is seldom well
preserved at either of these geological positions ; Roemer makes a similar statement
respecting its occurrence at Lindner Berges.

Pecten articulatds, Schloth. Tab. XXXIII, fig. 12.

Pecten articulatus, Schloth. Petref., pp. 227, 228.

— — Gold/. Petref., p. 47, tab. 90, fig. 10.

• — — Roemer. Verst., p. 68.

Testa ovato-acuta convexa, costis angustis actitis, subcequalibus cingidatis acuminatis, sul-
cis duplo latioribus concavis subtillissime transoersim striatis, auriculis inaqualibus lamelloso-
lineatis costulisque virgntis. (Goldfuss.)

Shell ovately pointed, convex ; radiating costse elevated, narrow, acute, more or less
unequal, with acute transverse lamellse ; interstitial sulcations wider than the costae,
concave, with delicate transverse striations ; auricles unequal, with radiating ribs crossed by
lineal lamellae. The more numerous ribs (about twenty-four), their irregularity and in-
equality, will distinguish it from P. vimineus, Sowerby, a species which abounds in the
Inferior Oolite.

Geological Positions and Localities. Pecten articulatus occurs in the Cornbrash of
the Yorkshire coast, and more frequently in the Calcareous Grit and Coralline Oolite of the
same county.

BIVALVIA. 33

Pecten Rushdenensis, Lye. Tab. XXXTII, figs. 4, 4 a, ^b, 4 c.

Testa cequivahi, mborbicuJari, acuta, auriculis ino'qualibus {auricula antica majora),
valvis plano-convexis rugis concentricis elevatis, crebris, infer tie sqicaiiiatis, squaiim brevibus,
regularibus delicatisdme instructis.

Shell eqiiivalve, suborbicular, acute, moderately convex ; auricles unequal (the anterior
one being the larger) ; the valves have a few plications of growth, and very densely arranged,
elevated, concentric rugse, which are slightly wrinkled towards the apices, but towards the
middle of the valves become short, regular, scabrous elevations, disposed cliecker-wise with
those above and beneath, so that when viewed obliquely tlie ornamentation resembles
that of an engine-turned watch ; this is more especially the case with the surface of the
right valve, which has the concentric rugse more delicate and closely arranged, and also
the scabrous elevations ; in other respects the valves are alike in the design of their
ornamentation.

A beautiful suborbicular species ; the minute scabrous elevations arrest the finger when
it is passed upwards over the surface. It is very rare.

Geological Position and Locality. The Cornbrash of Rushden, Northamptonshire, in
the collection of the Rev. A. W. Griesbach.

Pecten Wollastonensis, L?/c. Tab. XXXIII, figs 2, 2 a, 2 5, 2 e.

Testa ovato-orbiculari compressa, eequivalvi, aurieuUs incequalibus transverse plicatis et
radiativi. costatis ; valva dextra concentrice striata et radiatim costata ; striis tenuissimis,
inferne lamelloso-rugosis ; costis incequalibus nodosis ; ?mmerosis, in/erne evanescentibus ;
valva sinistra .striis subtillissiims concentricis regularibus.

Shell ovately orbicular, slightly convex, equivalve, with unequal auricles, the anterior
one being the larger ; they have numerous transverse plications and two or three radiating
costse ; the surface of the right valve has concentric striations and radiating costse ; the
striations are very fine and irregular ; the middle and lower portion of the valve is occupied
by irregular, scabrous, concentric plications ; the radiating costa3 are very numerous,
irregular, and knotted ; they gradually disappear towards the middle of the valve. The
left valve has very delicate, regular, concentric, densely arranged striations.

This rare Pecten diff'ers from Pecten Byonisius, Buv., chiefly in being equivalve, and in
the dissimilarity of the ornamentation in the opposite valves.

Geological Position and Locality. The Great Oolite of Wollaston, Northamptonshire,
in the cabinet of the Rev. A. W. Griesbach.

34 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Pecten Michelensis, Buvipiier. Tab. XXXIII, fig. 3.

Pecten cancellatus, Bean, ou Cornbrash Fossils, Mag. Nat. Hist., 1839 (no figure
or description).
— Michelensis, Buvignier. Paleont. de la Meuse, Atlas, p. 2-4, pi. 32, fig. 7.

Testa orbiculari, depresm maxima, conceiifrice rugosa et obsolete lineis suljpunctatis
irregutariter radiata, ad umhones costulis convexis, distaiitibus, regularibus radiantibm et
conceiitricis decussata ; umbonibus actitis ; auricidis iiKsqualibus, transverse costellatis.
(Buvignier. )

Shell orbicular, depressed, large, rugose in the adult state, with slightly defined, irregular,
radiating lines and large, irregular, concentric lanielJEB; the umbones are acute, the auricles
are unequal, the posterior auricle with large, rugose, transverse striations ; the surface near
to the umbo has regular, radiating costse, slightly knotted where they are decussated by the
concentric costae, which are nearly regular, and somewhat less closely arranged than those
which radiate.

The foregoing description applies to the right valve ; the change which the surface
undergoes in acquiring its adult condition is very striking, and is slightly indicated by the
few last lamellae upon the specimen figured ; a very fine example in the Scarborough
Museum, from the CoralHne Oolite of Malton, shows that it ultimately acquired the aspect
of Hinnites, thus losing all regularity in its ornamentation, and having very large, irregular,
squamose lamellse ; the left valve has not been obtained.

Pecten retiferus ( ' Gr. Ool. Monogr. Biv.,' p. 9, tab. i, fig. 15) approaches to it in the
kind of ornamentation, but has the radiating costa? larger and more distant, as are also the
concentric lamella' ; the umbones are less acute, and the auricles, which have a different
figure, are more nearly equal. Under the name of Pecten cancellatus, it was inserted by
Mr. Bean in his hst of Cornbrash fossils, but without either figure or description. The
splendid work of M. Buvignier on the ' Palaeontology of the Meuse' exemplifies an aged
specimen, together with the progressive changes which the ornamentation of the surface
underwent.

Geological Positions and Localities. The specimen figured is from the Cornbrash of
Scarborough ; it occurs also in the Coralline Oolite of Malton ; M. Buvignier has recorded
it in the same formation at St. Mihiel and at Donaument.

Pecten anisopleurus, Buv. Tab. XXXIII, figs. 5, 5 a.

Pecten anisopleurus, Buvignier. Paleont. de la Meuse, Atlas, p. 23, pi. 19, figs.
31-35.

Testa subrotunda, depressa, incequivalvi ; valva sinistra subplana, quinquecostata, lamellis
concentricis, fibrosis, interdum interruptis, subtextis, ornata ; costis distantibm, convexis,

BIVALVIA. 35

squamatis, iiifervallis, friplolafioribus ; costis extremis minoribus ; auriculls subcequallbKS,
transverse lame/losis. Valva dextra convexiori quinquesulcata, conceutrice teimifer lameUosa ;
sulcis concavis, costis altera; valvce resjjondentibus ; costis latioribus convexis, subdivisis.
(Buvignier.)

Shell suborbicular, inequivalve, depressed. The left valve nearly flat, with fine radiating
ribs, separated by very wide intervals ; the costae have large, squamous plications, rather
irregular, and nearly disappearing as they approach the apex, the costae near to the margins
being the smaller ; the intervals between the costas have five regular, concentric, squamous
plications ; the auricles are nearly equal, they are transversely lamellated. The right
valve is convex, with five radiating sulcations, corresponding to the five costae of the other
valve; the whole surface of the valve is covered with delicate, regular, concentric, closely
arranged lamellae. The interior of the valves present an appearance corresponding with
the ornamentation of the exterior.

Height rather greater than the breadth, and thrice the diameter through both the valves.

Geolof/ical Position and Locality. The Cornbrash of Scarborough and of Northampton-
shire ; the collections of ]Mr. Leckenby and of the Rev. A. W. Griesbach contain fine
specimens. M. Buvignier quotes the species from the lower ferruginous beds of the Oxford
Clay, Ardennes and Meuse.

HiNNiTiiS GRADus, Bean, sp. Tab. XXXIII, figs. 10, 10 «.
Pecten gkadus. Bean. Mag. Nat. Hist,., 1839.

Testa valva sinistra, ovato orbiculari convexo-plana, radiatim iindidato costata et con-
centrice lineata ; uviboni acuta submediano, auricula antico magna, oblique radiatim lineatis ;
auricula postica subnullo ; castulis radiantibus numerasis, casta una majora et minora al-
ternatim instructis, semel varicibus duabus radiantibus magnis. Lineis decussantibus densis
regularibus ; valva ajfixa ignota.

Shell with the left valve ovately orbicular, somewhat convex, the surface irregular, with
unequal, undulating, radiating costae and concentric lines; umbo acute, mesial straight, the
anterior auricle large, vi'ith oblique radiating lines, the posterior auricle scarcely produced ;
the surface of the valve has very numerous, unequal, radiating, rounded cost«, in two series,
a larger and a smaller costae being arranged alternately ; there are also two elevated,
irregular, large, radiating varices upon the middle of the valve, as in Hinnites abjectus.
The costae are about equal in width to the intercostal spaces ; the entire surface of the
shell has densely arranged, very regular, concentric hnes, which are scarcely visible without
the aid of a magnifier. The other valve is unknown.

Nearly allied, both in figure and aspect, to Hinnites abjectus, from which it is dis-
tinguished by the regularity and smoothness of the costae and by the regular, concentric
lines crossing both the costae and the intercostal spaces ; the latter are equal in width to the

36 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

costse, whereas H. ahjec'tus cannot be said to have any intercostal spaces, every part of the
surface being occupied by unequal, crowded, nodose costae ; the two large, radiating, nodose,
elevated varices are alike in both species.

The specimen figured is the original example, which belonged to Mr. Bean ; it has lost
a portion of the surface near to the lower bolder, and also a portion of the apex, nor will
it appear remarkable that only a single specimen of a shell so thin and fragile should have
been disengaged from a rock so intractable as the Cornbrash of Yorkshire.

Geological Position and Localiti/. The Cornbrash of Scarborough, in the collection of
Mr. Leckenby.

AvicuLA CLATHRATA, Li/c. Tab. XL, figs. 7, 7 a, 7 b.

Testa parva suborbiculari, convexo-jilana, valva sinistra auriculis subcequalibus magnis ;
sitperjicie costis radiantibus {circa 24) acutis, regularibus et nodosis, lineis concentricis dis-
fantibus decussatis ; valva altera subplana, laevigata, inornata.

Shell small, suborbicular ; the left valve with a low convexity, with large and nearly
equal auricles ; the surface of the valve has about twenty-four regular, acute, and slightly
knotted radiating costae, which are decussated by a few distantly arranged, concentric,
elevated lines ; the costae radiate equally over tlie auricles and the middle of the shell.
The right valve is more flattened, it is smootli and destitute of ornamentation. Diameter,
about three lines.

Geological Position and Locality. The Great Oolite of jNlinchinhampton ; a single
specimen.

AvicuLA suBCOSTATA, Roemcr, sp. Tab. XL, fig. 24.

MoNOTis SUBCOSTATA, Boemer. Nord. Ool., p. 75, t. 4, p. 7.

Testa orbiculari subobliqua, convexa, longifudinaliter costidata, subtillissime concenfrice
striata, costulis (10 — 14) remotis superne evanescentibus, incequalibus, auricula lavi,
umbonibus minimis antrorsum incurvis. Valva sinistra. (Roemer.)

Shell orbicular, rather oblique, convex, longitudinally costulated, and with very
delicate concentric striations; costellaj (10—14) acute, distinct, rather unequal, and dis-
appearing towards the umbo ; auricles plain ; umbo small, curved forwards. The right
valve is not known.

A small shell ; much less convex, less oblique, with a shorter hinge-line and more
delicate ribs than A. costata. Sow.

Geological Position and Locality. The Great Oolite of Minchinhampton Common, at
which place it is very rare.

BIVALVIA. 37

Gervillia tortuosa, Sow., sp. var. Tab. XL, fig. 25.

Gastroch^na tortuosa, Sow. Min. Con., t. 526, fig. I.

— — Phil. Geol. York., t. 11, fig. 36.
Gervillia tokthosa, Mor. Catal. Brit. Foss., 1854, p. 168.

— — Oppel. Juraformation, p. 418.

Testa eh»gata, antice tortuosa, postice recto, attenuato, umboni peroUiquo, siibter-
minali ; linea cardinis ohliquissimo ; margine antico undulato, ^Mcis concentricis Iceviter
instructis. Valva dextra subconcava, tortuosa ; fades interna ignota.

Shell elongated, convex, and contorted anteriorly, straight and attenuated posteriorly ;
umbo very oblique, with a small anterior auricle ; binge-border very oblique, anterior
border undulated ; the surface of the valve has five irregular, concentric plications upon
its anterior side. The right valve is twisted conformably with the left valve ; it is some-
what concave. The cardinal ligamentary pits have not been exposed in the present variety.
Compared with the Inferior Oolite forms of Gervillia tortuosa, this variety is more
narrow and less contorted, having the posterior extremity nearly straight ; the umbo is
also more acute, and the surface is destitute of the large, rugose, concentric plications
which are conspicuous upon well-preserved examples of the typical form. So much
variability, however, is seen in the contorted species of Gervillia that I prefer to regard
the present as pertaining to G. tortuosa, but constituting a well-marked variety.

Geological Position and Locality. It occurs rarely in the Cornbrash of Scarborough j
from the collection of Mr. Leckenby.

Gervillia Islipensis, Lye. Tab. XL, fig. 35.

Testa, valva sinistra cras.sa, obliqua, convexa, linea cardinis elongata, auricula postica
piermagna, fahiformi, dorso angulo obtuso obliquo instructo ; plicis incrementi paucis. Valva
altera etfoveoUs interni ignotis.

Shell with the left valve thick, inflated, very oblique, with a lengthened hinge-line and
falciform postei'ior auricle ; the anterior border is slightly excavated, and there is an
obtuse, oblique angle, which extends from the umbo to the posterior extremity of the
valve, which is curved backwards ; the folds of growth are few and prominent ; the
surface is destitute of ornament. The other valve is not known, nor has the iiinge been
exposed.

The general figure much resembles that of G. crassicosta, Mor. and Lye, but it is
more inflated ; it has a greater posterior curvature, and is destitute of the oblique costse.
The length of our largest example is 2 inches, that of the hinge-line Ig inch.

Geological Position and Locality. The Cornbrash of Islip, Oxon., also the Great
Oolite of Stonesfield ; collected by Mr. Whiteaves.

38 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Peiina foliacea, Lye. Tab. XXXVII, figs. 3, 3 a.

Testa ampla subceqiiivalvi, subplana, umbonibus prominulis acutis ; latere antico
excavato, mar(jine posteriore et inferiori elliptico curvafo ; laferibtis ruffis concentricis
paucis irreyularibus. Foveolis iiitenii ipiotis.

A large, subsequivalve, depressed shell, with prominent, pointed umbones, excavated
and thickened anteiior border, the hinge-line short, the posterior and inferior borders
elliptically ronnded, the general figure being mytelliform, the left valve being somewhat
more convex than the other ; the test is thin, with delicate margins.

Dimensions. Length, 4^ inches ; opposite diameter, 2^ inches ; the hinge-area has
not been exposed.

Geological Position and Locality. The Great Oolite of Minchinhampton Common ;
a single fine specimen of each valve is in the collection of the anthor, who is not cognizant
of any other examples.

Inoceramus quadratus. Sow., sp. Tab. XXXVIII, figs. 1, \ a, \b.

Perna quadrata, Sow. Min. Con., t. 492, non Phil, non Goldf.
— — Lycett. Ann. and Mag. Nat. Hist., 1855.

Testa tenue subquadrata, transversa, incequivalvi, valde inaquilatera, valva sinistra
antice oblique injlato, postice compresso ; umboni magno, subinvoluto, antrorsum instructo ;
linea cardinali subhorizontali elongato ,• latere anteriare truncato, infra umbonem concavo,
hasi subrecto, superficie ruyis coticentricis paucis irreyularibus. Valva dextra planata
umboni parvo antico. Foveolis interni parvis numerosis.

Shell thin, snbquadrate, transverse, inequivalve. The left valve inflated anteriorly,
with a large, subinvolute, projecting beak, and a steep, truncated and excavated slope
beneath it ; the posterior side is very thin, compressed, and expanded ; the hinge-line is
lengthened and nearly horizontal ; the base is lengthened and nearly straight. The right
valve is flattened ; the umbo is small, pointed, and anterior. The internal hinge-pits are
placed upon a narrow, lengthened plate ; they are small and numerous. The surfaces of
the valves are smooth, with a few irregular, concentric plications.

The diagnosis in the ' Mineral Conchology ' is as follows : — " Quadrilateral, one side
shorter than the other three; valves gibbose, unequal, the shorter side very concave,
bounded by two obtuse carinae."

The figure in the ' Mineral Conchology ' has the right or smaller valve facing the
spectator ; the contour of the larger or convex valve is not seen ; even the outline is not
perfect, as there seems to be a portion of the lower (right) border wanting, and thus
forming an angle at its anterior extremity, which would be rounded in the perfect shell ;
but the whole is stated by the author to be little better than a cast. With such an

BIVALVIA. 39

illustration it is not surprising to find that in the plates to the ' Geology of Yorkshire,'
and in the ' Petrefacta ' of Goldfuss, two very different species of Perna (flattened,
equivalve, and rugose) were figured for the Perna quadrata of Sowerby.

The convexity of the left valve, little remarkable in young specimens, becomes very
considerable with advance of growth ; the test upon the anterior side is moderately thick,
but the posterior side is delicate and is rarely preserved entire. Upon the smaller of the
specimens figured the portion denuded of the test exhibits obscure, concentric, and
radiating striations in the convex valve ; the same feature is also visible upon the surface
of the cast of the smaller valve figured by Mr. Sowerby ; it must therefore have existed
upon the inner surface of the very thin, nacreous layer of the test, which has not been
preserved; the exterior surface of the test is quite destitute of ornamentation.

Dimensions. Length of our largest specimen, in the direction of the hinge-line,
5y inches; height, 3| inches; convexity of the larger valve, 2j inches.

Geological Positions and Localities. Mr. Sowerby's specimen was obtained in the
Cornbrash at Bhlwick, Northamptonshire, and, as far as can be ascertained, no second
example has been obtained from that locality. In the Inferior Oolite of the vicinity of
Nailsvvorth the present author has procured specimens at sevsral quarries, in a single
bed ; its position being the highest bed of the white building-freestone, and immediately
underlying the bed of hard, cream-coloured limestone with Nerina;as, which appears to be
special to the Nailsworth valley. Perna quadrata does not appear to be very uncommon ;
but owing to the thinness of the fibrous test, it can only be disengaged from the Oolite by
a tedious and difficult process ; more frequently, however, the shell is found to have been
crushed or imperfectly preserved at its posterior side.

Lima pectiniformis, Sc/doth. Tab. XXXVI, fig. 1. Part II, Tab. VI, fig. 9. '

In figuring a larger and more characteristic example of this shell some additional
remarks may be allowed. It is widely diffused, abundant and of large dimensions in the
upper portion of the Inferior Oolite, rare and delicate in the Great Oolite, rare in the
Cornbrash, in the Kelloway Rock and Oxford Clay ; it reappears in considerable numbers
in the Coralline Oolite, assuming all its pristine varieties of form ; these are sufficiently
remarkable. In its young condition it was gregarious, and probably was attached by one
of the valves to the ground ; such, at least, seems an easy explanation of the fact that the
upper surface of a slab of stone covered with the species usually discloses only the inner
surfaces of single valves, the other valves having probably been removed by marine action
in their dead state ; but although young and thin, the specimens in this condition often
attained to the full dimensions of the species, the radiating flutings of the external surface
being almost equally strongly marked upon the inner surfaces, in which state, also, the
muscular scar is not distinguishable, and when the valves are closed the umbones touch
each other. In old specimens, owing to a continual deposition of shell upon the inner

40 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

surface, more especially towards the umbones, the triangular sub-urabonal area is large
;ind oblique, so that the umbones then are widely divergent ; the internal radiating flutings
have gradually disappeared, or are only visible at the lower border of the valves ; the mus-
cular scar is conspicuous ; ultimately, each valve acquired at its umbonal extremity a
thickness of two inches and a half, the cavity of the interior became much smaller, the
outer surface ceased to be extended at its borders during this internal accretion of shell ;
we may also infer, from its solid, ponderous mass, and from the frequency with which it
became perforated by the Lithophagidge, that, unlike the common Limse and Pectens, its
hal)its were sedentary ; doxxbtless these perforations may have been made in dead shells,
but they are not to be discovered in any other of the Jurassic Limte.

The test consists of two very distinct layers ; the outer layer is always thin and semi-
transparent, the inner layer is white, opaque, laminated, and received continual additions
to its thickness ; in brief, the structure and mode of growth agrees with that of the genus
Spondylus as fully as does the external aspect of the imbricated rugae and the tubular,
spine-like processes ; it is, in truth, an equivahe Spondylus, desfitide of hinge-teeih. The
variations of figure are also considerable ; sometimes sub-orbicular, with no more obliquity
than a Pecten or Spondylus, with the sides nearly equal, the radiating costae undulating
and irregular, as in Hinnites ; in other instances it is oblique, with a steep anterior slope ;
add to this latter figure a greater lengthening of the valves, a compression of the posterior
side, and the aspect becomes strictly that of Lima, as in L. squammicosta, Buv., which
appears to be only the young condition of this variety.

Few shells differ more in the convexity of the valves ; occasionally an example will be
found so nmch inflated that its figure can only have resulted from having been moulded
upon and remained closely adherent to a convex surface, to which the missing valve
probably remained attached.

The shell is not insequivalve, although such an appearance is often imparted to it
from a depression, or an irregularity in the convexity of one of the valves; as, however,
the borders of the valves are found to fit perfectly, this distortion cannot be owing to the
effects of fossilization.

Even from the earlier days of palaeontology this shell has been a source of
doubt and perplexity. Schlotheim referred it to Ostracites, as also did Ziethen.
Mr. Sovverby, in the ' Mineral Conchology,' placed it with Lima, but expressed doubts as
to the genus; more recently, Professor Quenstedt, in his 'Jura,' after alluding to the
features which distinguish it from the ordinary Limae, divides it into two varieties, one
having a thick and the other a thin shell ; he concludes by assigning it to the genus
Ostrea, but without offering any proofs that it would be correctly placed with the latter
genus. The change from the thin to the thick shell has already been explained, and the
structure of the test is distinct from that of Ostrea.

Lima pediniformis may be placed at the head of a group of Jurassic Limse which are
nearly allied, both in their external characters, shell structure, and mode of growth ; these

BIVALVIA. 41

are the following : L. Elea, D'Orb., from the Supraliasic Sands j L. Eledra, D'Orb.,
from the Supraliasic Sands and the Inferior Oolite; L. Hector, D'Orb., Inferior Oolite;
L. Luciensis, D'Orb., Great Oolite; L. rudis. Sow., Coralline Oolite; L. rotundata,
Buv., Coralline Oolite; L. a/iffusta, Buv., Coralline Oolite.

Lima punctatilla, Lye. Tab. XL, fig. 32.

Lima punctatilla, Lye. Ann. and Mag. Nat. Hist., 1853, p. 420.

Testa parva, injlata, ovato-oblon(ja, auricuUs parvis subcequalibm, lateribus leviter
excavatis ; costis radiantibus {circa 24) elevatis, granulatis, interstiis angustis, striis con-
centricis crebris decussatis.

Shell small, inflated, ovately oblong ; auricles small and nearly equal, the sides of the
valves steep and slightly excavated ; radiating (costse about 24), elevated, granulated ; large
upon the centre of the valves, and degenerating upon the sides into lines, decussated by
closely arranged concentric striations.

The general figure resembles Lima gibbosa, but more convex, and with radiating lines
or delicate costae upon the sides, which increase in size symmetrically towards the middle
of the valve, each rib being ornamented with a minute line of granules. The specimen
figured is of less dimensions than others, but it has only occurred very rarely.

Geological Position and Locality. The Great Oolite of Minchinhampton ; the Inferior
Oolite of Leckhampton Hill, in the shelly freestone.

Lima Helvetica, Oppel. Tab. XXXIII, figs. 8, 8 a.

Lima gibbosa, Goldfuss. Pet., t. 102, fig. 10, p. 86, non Sow.
— Helvetica, Oppel. Juraformation, p. 489.

Lima testa fornicata ovata subobliqua antice declivi, costis (25 — 27) subacutis adpressis
et linea later ali notatis, sulcis conformibus, lunula IcBvi convexa. (Goldfuss.)

Shell ovately obfong, convex, shghtly obhque ; anterior slope lengthened, steep ; pos-
terior slope more gradual and flattened; umbones acute, straight; anterior and posterior
auricles equal and but little produced, forming a short horizontal hinge-hne ; radiating
costae upon the middle portion of the valves narrow, sub-acute, 25 — 27 in number at the
lower border, 14 — 15 near to the umbo, the additional costae near to the lower border
consisting of smaller intervening costae or lines, unequal in size, and rather irregularly
arranged ; the larger costae towards the sides of the valves appear as if compressed upon
the shell. The anterior sides of the valves are nearly smooth, but each side has a few
very delicate radiating lines ; the entire surface of the valves has very delicate, closely
arranged, concentric, irregular striations, which impress the costae, and are very con-
spicuous upon the wide, flattened intercostal spaces ; the valves are close fitting and thin.

6

4:2 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Geological Position and Localities. It occurs rarely in the Cornbrash of Scarborough.
Dr. Oppel records it in the same geological position at Marquise, near Boulogne ; also at
Egg, near Aarau, Switzerland. Goldfuss records it at the latter locality, and at Basel.

Lima rigidula, Phil., sp. Tab. XXXIII, figs. 7, 7 a.

Plagiostoma eigidultjm, Phil. Geol. York., i. t. 7, fig. 13.

Testa elongata, convexa, per-obliqua, umbonibus obUquis, acutis, auriculis parvis sub-
cequalibus ; latere antico elevato, excavato, postico eUiptico curvato ; valvis costulis radi-
antibus angustis, rotuudatis, regularibm, sed undulatis et granulatis ; interstiis duplo
latioribus subtillissime transverse striatis, striisque regularibus insfructis.

Shell elongated, convex, very oblique ; umbones small, pointed anterior ; auricles
small, nearly equal ; anterior side very convex, with a steep, excavated border ; posterior
side curved elliptically; the entire surface has delicate but rounded, elevated, and finely
knotted radiating costse, gently vraved and separated by interstitial spaces twice the
breadth of the costae ; the spaces have very fine, regular, and closely arranged transverse
striations ; the plications of growth are few, but become prominent near to the lower
border.

One of the most elongated and oblique of the Jurassic Limae. The general figure and
ornamentation would much resemble Lima oralis, Sow., if the convexity of the anterior
side were not much greater, and the costae more elevated, in the Cornbrash shell ; the
striations are so densely arranged that the spaces do not present a punctated aspect, as is
usually seen when the striations are more distant, and larger.

Dimensions. Length, 20 lines; breadth, 12 lines; diameter through both the valves,
10 lines.

Geological Position and Locality. The Cornbrash of Scarborough, in which it is
abundant.

MomoLA GiBBOSA, Sow. Tab. XXXIII, figs. 11, 11 a.

MoDiOLA GIBBOSA, Sow. Min. Con., t. 211, fig. 2.

RENIFOKMIS, Sow. lb. fig. 3. ?

— — B'Orh. Prodr., i, p. 282.

— GIBBOSA, Mor. Catal., 1S5J, p. 210.

Testa elongato-ovato, convexa subreniformi umbonibus curvatis acutis sulco oblique
antico; latere antico infer ne sinuato, latere postico elliptico curvato ; lateribus plicis magnis
concentricis distantibus.

Shell ovately elongated, very convex ; umbones pointed, curved forwards ; an oblique
sulcation proceeds downwards and forwards to the lower part of the anterior border, which

BIVALVIA. 43

is sinuated ; the anterior side has a large, rounded, but compressed lobe ; the posterior
border is very convex, and is curved elliptically ; the surfaces of the valves have a few
large, irregular and distant plications.

The length is twice the breadth, and two fifths greater than the convexity of the united
valves.

The very inflated figure, the curvature of the valves, and the distinct anterior broad
sulcation, distinguishes it from other Jurassic species ; some specimens, smaller and appa-
rently younger, cannot perhaps be distinguished from Modiola reniformis, Sow., for the
species varies in the length, curvature, and convexity.

Geological Positions and Localities. This species is figured upon the authority of
specimens in the ]\Iuseum of Practical Geology, which are stated to have been collected in
the Cornbrash of Melbury Osmond. It is common in the Inferior Oolite of the southern
counties.

CUCULLiEA CORALLINA. Tab. XXXIX, fig. 3.

CucuLLiEA OBLOKGA, Phil. Geol. York., i, t. 3, fig. 34, non Sow.

— CORALLINA, Damon. Geol. Weymouth, Suppl., pi. 4, fig. 8.

Testa injlafa, subrhomboidali, suhmquilaterali, mnbo7iibus magnis medianis acufis,
incurvis, latere postico abbreviato abrupte truncato, area cardinis brevi, superjicie lineis
longitudinalibus crebris, irregularibus aliis radiantibus subobsoletis decussata.

Shell much inflated, subrhomboidal, nearly equilateral; umbones large, mesial,
incurved, elevated, slightly oblique, and nearly in contact.

The anterior side is produced and rounded, the posterior side is very short, abruptly
truncated, slightly excavated, and separated from the other portion of the surface by a
strongly defined subacute angle ; the hinge area is short and not wide ; the surface has
densely arranged, irregular, longitudinal lines, decussated by others radiating, but much
less clearly defined.

Dimensions. — Height, three fourths of the length.
A very short, tumid, abruptly truncated Cucullsea, possessing these characters in a greater
degree, and less oblique than any of the shorter examples of C. oblonga, Sow. ; the latter
shell has also several large, widely separated, radiating lines upon the anterior side, of which
our species is destitute. It appears to be identical with Cucullcea oblonga, Phil., from the Coral
Rag, at least with the more short examples of that species, for the Coral Rag shell presents
great variability in its general figure, more especially in that of the posterior side, and it is
easy to obtain specimens which insensibly connect the shorter with the more lengthened
and oblique forms ; it rarely happens that the surface ornamentation can be discovered,
but the portions of the surface obtained agree with that of the Cornbrash shell.

Geological Positions and Localities. Cucullcea corallina occurs rarely in the Cornbrash
of the Yorkshire coast, but is abundant in the Coral Rag of Pickering and of
Oxfordshire.

44 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

CucuLL^A CLATHRATA, Lsck. Tab. XXXIX, figs. 4, 4 a.

CucuLLaiA CLATHEATA, Leckenby. Joum. Geol. Soc, 1858, vol. xv, pi. 3, fig. 4.

Testa subrhomboidali injlafa, umhonihus antemedianis magnis, valde separatis, area
ampla, excavata, lanceolata, basi subrecto ; valvis rut/is longitudinalibus , irregularibus,
lineisque radianfibiis, crebris tetmibus, dorso atigulo obtmo et oMiquo.

Shell subrhomboidal, inflated ; umbones large, placed anterior to the middle of the
valves, separated by a large lanceolate area ; there is an oblique obtuse angle upon the
posterior side, separating a concave posterior space from the middle portion of the valves ;
the surface has large, longitudinal, irregular, rugose plications crossed by closely arranged,
delicate, radiating lines ; the lower border is nearly straight, and slightly sinuated.

The shorter posterior side and larger umbones distinguish it from Area lata, Dunker,
to which in other respects it has a considerable resemblance.

Dimensions. — Length, 26 lines; height, 14 lines; diameter through both the valves,
16 lines ; space separating the points of the umbones, 3 lines.

Geological Position and Locality. The Cornbrash of Scarborough, also in the
Kelloway Rock of the same locality. In the collection of Mr. Leckenby.

Ndcula Menkei, Roem. Tab. XXXIX, fig. 2.

NocuLA Menkei, Boemer. Nordd. Ool., t. 6, fig. 10, p. 98.

Testa ovata, medio ventrieosa concentrice striata, antice brevissima acuta oblique
truncata, cordato-subexcavata, posterius producta rotundata, basi subarcuata, umbonibm
crassis incurvis, aream lanceolatam hand efformantibus. (Roemer.)

Shell ovate, anterior side very short, somewhat excavated, and pointed at its lower
extremity ; posterior border lengthened, curved, sloping obliquely downwards, its lower
extremity rounded, base slightly curved elliptically, umbones large, incurved, area very
slightly defined ; the middle portion of the valves is moderately convex, with a few distant
plications of growth, and delicate concentric striations obscurely defined.

Nucula vnriatnlis, Sow., approximate.s to this species, but is without the anterior
excavation, and has a more lengthened posterior side. Nucula iiuclens, Desl., is shorter
and more globose.

Geological Positions and Localities. Roemer records Nucula Menkei in the Portland
Limestone of Wendhausen. Mr. Whiteaves has collected it in the Great Oolite of Kirk-
lington. and in the Cornbrash of Islip, Oxon.

BIVALVIA. 45

Genus — ^Isoarca, Munster.

Shell equivalve, ventricose ; umbones large, anterior or antero-inesial, sometimes more
or less spiral, ligament external ; hinge-border lengthened, curved, with two series of small
transverse teeth, which decrease in size towards the centre ; pallial impression simple.

ISOARCA SCARBURGENSIS, Li/c. Tab. XXXIX, figs. 5, 5 a.

Testa tenui, ovato-oblonga, tumida, umbonibils magnis subanticis, prominentibus, latere
antico brevi, curvato, postico elongato, oblique declivi, sulcis duobus evanescentibus ; margine
inferiore subrecto ; valvis striis concentricis irregularibus, inferne semel granulis irregularibus
imtructis.

Shell thin, ovately oblong, somewhat inflated ; umbones large, prominent, placed
anterior to the middle of the valves, directed obliquely forwards ; anterior side short and
curved elliptically, posterior side lengthened, the margin sloping obliquely downwards with
two slightly impressed oblique furrows, which are distinct towards the umbo ; the lower
border is lengthened and nearly straight ; the surface has fine irregular, concentric striations,
and the sides have towards their lower border irregular, rounded granules, rather distantly
arranged.

Dimensions. — Length, 24 lines; height, 16 lines ; diameter through the valves, 12 lines.

A fine and rare example of a genus which seldom occurs in the Jurassic rocks of this
country. It is much less inflated, and the umbones are more prominent than in Isocardia
transversa, Munst., less oblong, and with the anterior side more produced than in
Isoarca Lochensis, Quenst., and Isoarca emine?is, Quenst. Other Jurassic species more
remotely allied and approaching the orbicular figure are Isoarca sitbspirata, Munst.,
Isoarca texata, Munst., Isoarca decussata, Munst., and Isoarca cordiformis, Quenst. The
general figure resembles Cypricardia, but when the hinge cannot be exposed, the genus
may be distinguished by the granulations upon the surface, and by the tenuity of the test.

Geological Position and Locality. The Cornbrash of Scarborough, in the collection of
Mr. Leckenby.

Leda Anglica, B'Orh. Tab. XXXIX, fig. 7.

NucuLA LACHRYMA (obtuse v.iriety) Phil. Geol. York., i, pi. 9, fig. 25.
Leda Anguca, JfOrh. Prodr., p. 275.

Testa Icevigata parva, injlata, subtrigona, umbonibus medianis obtusis incurvis depressis,
latere antico curvato, oblique-declivi, latere postico ahrupte declivi, acute carinata, carina
obliqua promimula ; valvis striis longitudinalibus obscuris etplicis incrementi paucis impressis.

46 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Shell small, inflated, short, subtrigoiial ; umbones depressed, mesial, obtuse and incm-ved;
the anterior border is rounded, sloping downwards and uniting with elliptical curvature of
the lower border; the posterior side slopes abruptly downwards, it has an oblique posterior
carina, which becomes conspicuous and raised towards its lower extremity ; it separates a
posterior, depressed, lanceolate area from the sides of the shell. The surface has obscure
longitudinal striations, and several folds of growth.

The inflated figure, short posterior side and projecting oblique posterior carina, dis-
tinguish it from Leda lachryma. Sow., and also from other species of the Lower Oolites.

Geolor/ical Positions and Localities. The Cornbrash of Scarborough, in which it occurs
rarely. Professor Phillips records it in the lower stage of the Liferior Oolite (Dogger),
and in the gray limestone or upper stage of the same formation upon the coast of Yorkshire.

Trigonia elongata, Sow. Tab. XXXIX, figs. 6, 6 a.

Trigonia elongata, Sov:. Min. Con., t. -431.

— — B'Orb. Prodr., vol. i, p. 338.

— — Morris. Catal., 185-1, p. 228.

— — Oppel. Juraforraation, p. 525.

— — Damon. Geol. Weymouth, Suppl., pi. 2, figs. 1, 2.

Testa sudfriffona, aJta, convexa, antici Irevissiwa truncata, costis, magnis, subJwrizon-
ialibus, leviter undulatis ; umbonibus prominentibus acutis incurvis } area cardinaJi lata,
ornatissima, distincte tripartita, carinis promineiitibus, denticulatis.

Shell subtrigonal, very convex and lengthened ; anterior side short, its border abruptly
truncated with numerous large, nearly horizontal and slightly undulated costse ; the
umbones are elevated and nuich incurved ; the posterior area (which nearly equals in size
the other portion of the surface) is very wide, and is separated into three distinct parts by
as many prominent denticulated carinae ; the marginal carina is very large and nearly
straight ; the mesial and inner carinae though smaller are likewise conspicuous in both the
valves ; the space between the mesial and inner carina is much depressed and its orna-
mentation is very delicate; the superior or post ligamental space is short and wide, it has a
few elevated j)erpendicular plications. The convexity of the united valves is somewhat
greater than the breadth of the shell, and equal to two thirds of the length of the marginal
carina.

The general figure and other characters are so strongly defined that it will not readily
be mistaken for any other example of the group of the Costuta ; the figure of the Cornbrash
specimens agrees with those from the Oxford Clay, but the sculpture upon the area is less
strongly marked in specimens from the latter formation, which are also usually smaller.
Compared with other examples of the same group of species, T. elongata is remarkable
for the short, widely-separated horizontal costse, for the great size and straightness of the

BIVALVIA. 47

marginal carina, for the prominence of the sculpture upon tlie tripartite area, and more
especially for the shortness and great breadth of the superior or post-ligauiental space,
which, when the valves are united, becomes cordate rather than lanceolate. D'Orbigny
(Prodrome) believes it to be identical with T. cardissa, Agassiz, it is, however, only necessary
to compare the marginal carina in the two forms to perceive their distinctness.

Geolof/ical Positions and Localities. It is abundant in the Oxford Clay of the southern
counties, more especially at Radipole near \^'eyraouth, and in the Cornbrash of the coast
of Yorkshire, at Gristhorp, and at Scarborough. Tiie foreign localities cited are France,
Dives, Villers (Calvados), Clucy, Mont Orient, near to Salins (Jura), Montsec, near to St.
Mihiel (]\leuse), Marault, near to Chaumont (H. Marne), Beaumont, Pizieux, Chauffour
(Sarthe).

Trigonia tuberculosa, Li/c. Tab. XL, fig. 6.

Trigokia tobekcdlosa, Lycett. Ann. and Mag. Nat. Hist., 1850, p. 12, t. 11, fig. 9.
— — Morris. Cat. Brit. Foss., 1854, p. 229.

Testa ovato-trigona, subdepressa, umhonibus parvis, recurvatis, margine anteriore et
inferiore rotunda, margine posticd ewcavatd, area augustata, transverse plicata, plicis magnis
acutis ; carina marginali delicati nodulois ; carina interna varicibus magnis regularibus
ornata ; area lanceolata varicibus paucis obliquis ; valvis lateribus costis numerosis concen-
tricis et dense tuberculosis, tuberculis crebris elevatis, compressis.

Shell ovately trigonal, depressed ; umbones small, mesial and recurved, anterior and
lower borders rounded, superior border rather excavated ; area narrow, with two oblique
carinae, and with transverse acute plications, every second plication forming a varix upon
the inner carina ; the marginal carina is delicately tuberculated ; the post ligamental
lanceolate space is small, with several oblique varices ; the sides of the valves have very
numerous, closely arranged, concentric tuberculated, costa ; the tubercles are much elevated,
and compressed laterally, imparting to them a club-shaped figure, the lower extremity of
each extending to the succeeding costa.

A pretty little species, remarkable for the delicacy and salient features of its orna-
mentation. The characters of the tubercles upon the sides of the valves closely resemble
those in Trigonia elathrata Ag., but in other particulars the two species are widely
separated ; the close contiguity of the extremities of the tubercles between row and row
gives to them, when viewed from the posterior side, the appearance of forming a series of
vertical costae ; the tubercles are, however, very well separated in the rows, and towards
the lower border they project considerably from the sides of the valves ; eighteen rows of
costae may be counted in a specimen whose length is only nine lines.

Geological Positions and Localities. The specimen figured is from the cabinet of
the Rev. A. W. Griesbach, and was obtained by him from the Cornbrash of Rushden ; it

48 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

is silicified, and is a beautiful object for the delicacy of its ornamentation ; the original
specimen figured by me in the ' Annals and Magazine of Natural History,' was obtained
by the Eev. P. B. Brodie in the shelly freestone of the Inferior Oolite at Leckhampton
Hill ; at each locality it ranks as one of the more rare productions.

Trigonia clythia, VOrhigny. Tab. XXXVII, fig. 2 ; Tab. XL, figs. 5, 5 a.
Trigonia clythia, D'Orbigny. Prodr. de Paleont., i, p. 309.

" Coquille sinc/uUere par ses cotes concentriques formant de deux en deux mi angle sur
la region anale, independamment de la area costulee en travers." (D'Orbigny.)

Testa subtrigona, convexa, transversim costata, costis numerosis, crebris, curvafis,
postice alternatim angnlatis, carina marginali Itevigato, elevafo, area planatd transversim
costata, costis magnis, depressis.

Shell subtrigonal, convex, transversely costated ; costse numerous, small, closely
arranged, curved, convex upon their lower and concave upon their upper sides; the first
few costae are united to the marginal carina, the succeeding costal are bent suddenly
upwards at their posterior extremities, forming a series of angles, one of which proceeds
from every second costa ; the marginal and inner carinse are smooth and elevated ; the
area is moderately wide, flattened, traversed transversely by a few large depressed and
waved costsc, which are interupted by an oblique mesial furrow.

The general figure is nearly triangular ; the umbones are mesial, much elevated and
pointed ; the anterior border is nearly straight, sloping obliquely downwai-ds, but slightly
sinuated immediately beneath the umbones; the posterior border is short and oblique.

Dimensions. — The height and the lateral diameter are nearly equal; the diameter
through both the valves is one fifth less.

The costse upon the sides of the valves are so closely arranged that about twenty
occur in a specimen seven lines in height.

Geological Positions and Localities. The Great Oolite of Minchinhampton and Bisley
Commons, also in the upper zone of the same formation near to Bath. Luc (Calvados).

Trigonia Scarburgensis, Lgc. Tab. XXXVII, fig. 1.

Testa ovato-trigona subdepressa, elongata, umbonibus recurvatis, margine antico rotundo,
postico excavato, producto ; area angusta, elongata, carinis tribus delicatissimis ornato ;
valvis costis tuberculatis, magnis per series leviter arcuatis, antice parvis, irregularibus,
postice magnis curvatis.

Shell ovately trigonal, rather depressed, elongated ; umbones recurved ; anterior side
rounded and produced ; posterior slope somewhat concave, lengthened ; the area is narrow,
flattened, with irregular transverse striations, and ornamented with three very delicate

BIVALVIA. 49

knotted carinse, the lanceolate, post-ligamental space is much lengthened, smooth, and
excavated. The costated portion of the shell has the rows at first regular and concentric,
with regular, distinct tubercles ; subsequently the costse become more ridge-like and the
tubercles less separated ; anteriorly they are small, and the rows are broken and confused ;
posteriorly they are large and more regular, curving upwards slightly, but their extremities
are well separated from the marginal carina.

This is the shell attributed by Messrs. Young and Bird to T. davellata, and subsequently
also by Professor Phillips, Professor Williamson, and Mr. Bean, in their lists of Cornbrash
fossils.

Trigoiua signata, Ag., figured in the second part of the Great Oolite Monograph
under the name of Triyonia decorata, is also an elongated shell, but is destitute of the
recurvature of the umbones and of the produced anterior side ; the rows of costa3 likewise
differ; the posterior portions are not larger than the anterior, and there is wanting that
arrest in the continuity of the rows always conspicuous in the Cornbrash shell, and which
imparts to the anterior portion of the latter form a broken, irregular character.
Triffonia davellata, Lhwyd, Parkinson, and Sowerby, so abundant in the Lower Cal-
careous Grit of England, Prance, and Switzerland, has a much shorter and more convex
figure, the umbones are not recurved, features which will suffice to distinguish them
irrespective of the ornamentation of the siuface. T. perlafa, Ag., and T. Bronnii, Ag.,
from the same beds, appear to be only varieties of T. davellata. Trlgonia Scarburgensis
is also allied to that beautiful and well-known Oxford Clay representative of the ClavellatcB
so long procured at Weymouth, and of which a good figure is given in Mr. Damon's
'Geology of Weymouth,' Suppl, pi. ii, fig. 3; the latter, in addition to the unusual
elongation of its posterior side, has a wide diagonal space, destitute of ornament, separating
the posterior extremities of the costse from the marginal carina.

Geological Position and Localifg. Trigonia Scarburgensis is moderately common in
the Cornbrash of the Yorkshire coast ; it may also occur in the same rock of the southern
counties, but the condition of the specimens is such that it has not been ascertained with
any confidence.

Trigonia Cassiope, D'Orb. Tab. XXXVII, fig. 10.

Trigonia Cassiope, D'Orb. Prodrome de Paleont., 1, p. 308.

Testa ovato-trigo/ia, transverse elongata, subdepressa, costis transversis, subhorizontalibus,
numerosis, lavigatis, gracilibus curvatis, antice rotundata, postice produeta ; area tricari-
nata, carina marginali et interna crenulata, carina mediana parva ; carinarum intervallo
costdlis longitudinalibus granosis, confertis, ornatis ; area postica lanceolata, delicate
reticulata.

Shell ovately trigonal, transversely elongated, somewhat depressed ; transverse costae

7

50 . SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

numerous, smooth, slender, nearly horizontal, and gracefully curved ; the anterior border
is rounded ; the area is lengthened, narrow, and slightly excavated, having three carinae,
of which the marginal and inner carinae are conspicuous, curved, and crenulated ; the
median carina is small ; the spaces between the carinae have longitudinal, delicate, closely
arranged, granulated little costae ; the post-ligameiital lanceolate space has a very
delicately reticulated surface.

A transversely lengthened, large, and gracefully curved form, much less convex than
1\ cosfafa, with more depressed umbones, and having the anterior side greatly more
rounded and produced. The costated portion of the shell is very large ; the costae are
numerous, not much elevated ; their direction is nearly horizontal, excepting near to the
apex, where they have an elegant sigmoidal curvature. The length upon the marginal
carinae is one fourth greater than the opposite measurement ; the diameter through both
the valves is somewhat less than half the height. The area is very narrow and length-
ened, the ornamentation of its surface is minute and delicately sculptured, the general
figure is depressed, which, together with the small prominence of the umbones, the
excavated posterior side, and the large, rounded anterior side, will, in the aggregate, serve
to distinguish it from other allied forms.

Geoloffical Position and Localities. It is moderately abundant in the Cornbrash of
the coast of Yorkshire. The foreign localities quoted by D'Orliigny are Luc (Calvados),
Vezelay (Youne), Grange-Henry, near Nantua.

Trigonia compta, Li/c. Tab. XL, fig. 1.

I'esfa ovato-trit/ona, subdepressa, umbo7iibus obfusis, depressis, latere antico brevi,
rotunda, postico prodi'cfo ; area planata, carinis tribus delicatissimis et striis travsversis
tcnuissiviis instrudis, costis {circa \2) postice nodulosis, interruptis, antice rugis ohliquis
instrKctis.

Shell ovately trigonal, rather depressed ; umbones obtuse, depressed, not recurved ;
anterior side short, rounded, posterior side more produced, its border straight, sloping
obliquely downwards ; area flattened, with three very delicate, tuberculated carinae, and
fine transverse striations, lanceolate; post-ligamental space narrow, lengthened, and smooth.
The other portion of the surface has about twelve rows of costae, which become large, hori-
zontal, nodulose, interrupted varices posteriorly, and form small, oblique, rather imperfectly
tuberculated, but continuous costae anteriorly, so that all the costae reach the anterior
border in an obhque rather than in a concentric direction.

The diagnostic characters are not very strongly marked, but in the aggregate are
sufficiently distinctive. The delicately ornamented area separates it from T. Moretonis,
Mor. and Lye, and the posterior, interrupted varices from T. iiiipressa, Sow. Erom T.
Goldfussii, Ag., it is distinguished by the smaller oblique costae, more especially of their

BIVALVIA. 51

posterior extremities, where they do not form large, continuous varices, bent upwards at
a considerable angle, as in the latter species. T. costatula. Lye, is more convex, the
costae are more regular, smooth and concentric, the area also is much larger, which imparts
a subquadrate figure to the outline ; other species are more remotely allied.

Geological Position and Locality. The slate of Collyweston, Northamptonshire, in
which the specimens are usually compressed.

Trigonia clythia, lyOrb. SuppL, p. 48, Tab. XXXVII, fig. 2 ; Tab. XL, fig. 5.

Some fine specimens received subsequently to the printing of page 48 have enabled
the artist to illustrate the more adult aspect of this species. Tab. XL, fig. 5 a exhibits
the nodulous character of the posterior extremities of the costse, their anterior portions
remaining regular and concentric ; fig. 5 is an aged specimen, exhibiting further changes.
In common with many other of the Jurassic Trigoniae in the ultimate stage of growth, the
smooth costae are no longer regular or concentric ; they become less distinctly marked,
broken, imdulating or wrinkled, constituting the approach to the period when all orna-
mentation ceases.

Trigonia tripartita, Forbes. Tab. XL, fig. 4.

Trigonia tripartita, Forbes. Journ. Geol. Soc, vii, tab. 5, fig. 11.
— — Morris. Catal., 1854, p. 229.

Testa ovato-trigona, subdepressa, umbonibus obtusis sed recurvatis, latere antico rotmido,
postico subconcavo oblique declivi, antice costis Icevigatis parvis obliquis crebris, postice
aliis (7 — 8) obliquis magnis depressis, nodulatis ; area subconcava, sulco viediano obliquo,
costis transversalibus penes apicem instructis.

Shell ovately trigonal, rather depressed ; umbones obtuse, but recurved ; anterior margin
rounded ; posterior margin somewhat concave, sloping obliquely downwards ; the anterior
side has numerous (about thirty) delicate, oblique, smooth costse, which are interrupted
posteally by others which cross them nearly at right angles ; the latter costee (about seven
or eight) are large, nodulous and depressed, the two latter only reach the lower border ;
the marginal carina is but little conspicuous ; the area is somewhat concave, it is transversed
by a mesial furrow, and has a few transverse costse near to the apex. Our specimen is
slightly imperfect at the apex and at the inferior border.

Geological Positions and Localities. A single example from the Cornbrash of Chippen-
ham, in the collection of W. Walton, Esq. This pretty species was also obtained by the
late Professor E. Eorbes in a stratum of yellowish, crumbly limestone and shale, beneath
the Oxford Clay at Lock Staifin, in the Isle of Skye, associated with fresh- water and marine

52 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

testacea, whicli are believed to represent estuary conditions, a geological horizon which
possibly is not very dissimilar to that of our specimen.

Trigonia arata. Lye. Tab. XL, fig. 2.

Testa ovato-trigona, subdepressa, umbonibus antemedianis, obtusis depressis, latere
antico brevi, rotundo, postico oblique declivi, area planata, oblique irrec/ulariter, striatis,
carina marginali subnullo, lateribus costis antice obliquis, postice angidatis, depressis, sim-
plicibus. Testa cetate juniori costis conceiitricis siu/plicibus.

Shell ovately trigonal, somewhat depressed ; umbones anterior to the middle of the
valves, obtuse and depressed ; anterior side short, rounded ; posterior side sloping obliquely
down ; area flattened, with transverse, irregular striations ; marginal carinas not conspicuous,
and obsolete posteriorly ; the sides of the valves with numerous closely arranged, oblique,
plain costae, which are bent upwards posteriorly at an obtuse angle, and meet the area at
a right angle.

Tlie costae are rounded and rather depressed ; they become more distantly arranged
posteriorly, but only slightly increase in size. The young shell has the costae regular
and concentric ; the marginal carina is small, but forms a distinct elevation ; a specimen
more aged than the one selected for our figure has the posterior portions of the costse
slightly nodulous ; anteriorly they become waved and irregular.

Geological Positions and Localities. A rare species ; Mr. "Walton's specimens are
from the Forest Marble of Farleigh, near Bath ; it has also occurred in the same position
near to Cirencester.

Trkjoma Bathoxica, Lgc. Tab. XL, fig. 3.

Testa subtrigona, defressa, umbonibus altis medianis, latere antico et postico subrecto,
oblique declivi, lateribus costis elevatis, angustis, crebris, sitbundulatis, et spinulosis,
oblique instrucfis ; area parva planata oblique striata, carina marginali ininiino, subnullo.

Shell subtrigonal, short, depressed ; umbones elevated, mesial, and not recurved ; anterior
and posterior borders nearly straight, sloping obliquely downwards, the surface with
numerous (about twenty-four) narrow, elevated, spinose, and somewhat undulated oblique
costse, which are directed from the marginal carina anteally downwards, and all reach the
lower margin ; the area is narrow and obliquely striated ; the marginal carina is very small,
and rather indistinct.

The narrow, ridge-like costae have numerous minute, obtuse spines, which impart
roughness to the surface ; they are distinct, rather irregular, and therefore very different
from the serrated, elevated, regular costae of T. striata. Miller, and its allied species ; the

BIVALVIA. 63

general aspect resembles T. duplkata. Sow., but it has no bifurcating costse near to the
lower border, and is also destitute of concentric costae near to the apex. The sole specimen
at our disposal is imperfect at the posterior extremity ; it has twenty costae, and would
require about four others to complete its surface. Possibly Trigonia Cyhele, D'Orb.,
from the Great Oolite of Luc, may not differ from this species, but the seven words allotted
to it in the ' Prodrome' of that author are insufficient to characterise it.

The figure is nearly that of an equilateral triangle, each of the sides having a length
of about an inch.

Geological Position and Localifi/. In rubbly, hard, ferruginous Oolite (Great Oolite)
from the Box Tunnel ; communicated by W. Walton, Esq.

Cardium lingclatum. Lye. Tab. XXXIII, figs. 2, %a; Tab. XXXV, figs. 11, \\a.

Testa ovato-ohlonga, mediocriter convexa, umbonibus prominentibus, mediums, subamtis,
valvis maryinibus ellipticis curvafis, ruyis concenfricis irregularibus, striisque termibus,
delicate ivipressis ; postice striis obliquis regularibiis decussatis.

Shell ovately oblong, moderately convex ; umbones prominent, mesial, and subacute ;
the anterior, posterior, and inferior margins of the valves are elliptically curved ; the
surface has numerous irregular, concentric rugae, and delicate, regular striations ; the
posterior side has some regular, oblique striations, which decussate those which are con-
centric. The height and the transverse diameter are equal.

Allied to Cardium cognatum, Phil., but the latter has much greater convexity, it has
larger and less pointed umbones, its surface is also destitute of the concentric rugae and
striations.

Geological Position and Locality. The Great Oolite of Kirklington, Oxon., collected
by J. P. Whiteaves, Esq.

Cardium incertum, Phil. Tab. XXXV, figs. 14, 14 a.

Cardium incertum, Fhil. Geol. York., i, pi. 1 1, fig. 5.
Unicardium incertum, VOrh. Prodrome, i, p. 279, No. 323.
Cardium incertum, Morris. Catal., 1854, p. 192.

Testa suborbiculari convexa, Icevi, umbonibus submedianis elevatis subacutis incurvis,
margine antico concavo, lunida suhmlla ; latere postico planato angulo obliquo formante,
margine postico subrecto in/erne angulato ; lateribus plicis concentricis paucis, irregularibus

et tenuibus.

Shell suborbicular, moderately convex, smooth ; umbones mesial or slightly antero-mesial,
elevated, acute, and incurved; anterior border concave and rounded; lunule scarcely

54 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

defined ; posterior side forming a flattened area, well separated fi'om the other portion of
the surface by a clearly defined, oblique, and acute angle ; the posterior border, at first
curved, slopes suddenly downwards, nearly in a straight direction, forming an angle at its
junction with the lower border ; the surface has a few faintly marked, irregular, concentric
plications.

Dimensions. — Length, 13 lines ; height, II5 lines; diameter through both of the valves,
8 lines. The binge has not been examined.

Geological Positions and Localities. The fine specimen- figured was collected by J. F.
Whiteaves, Esq., in the Great Oolite of Kirklington, Oxou. It occurs rarely in the Inferior
Oolite of Blue Wick ; it was also collected in the roe stone of the Inferior Oolite at Leek-
hampton Hill by the Rev. P. B. Brodie.

Cardium cognatum, Phil. Tab. XXXVI, figs. 3, 3 a.

Cardicm cognatum, Phil. Geol. York., i, t. 9, fig. 14.

— COGNATUM, Morrii. Catal., 185-1, p. 192.
Unicardium cognatum, B'Orb. Prodr., Et. x, No. 324.
— — Oppel. Juraforniation, p. 410.

Cardium — Leckenby. Journ. Geol. Soc, xv, pi. 3, fig. 8.

Testa ovato-orbieulari, convexa, umhonihus magnis, medianis, subrectis, margine
antico et postico, elliptico curvato, lunida nulla ; valvis striis concentricis, crehris, instructis;
postice striis radiantibus obliquis decussatis.

Shell ovately orbicular, convex ; umbones large, prominent, mesial, straight, or directed
slightly forwards ; the anterior and posterior margins of the valves are curved elliptically ;
there is no lunule ; the whole surface has very densely arranged, delicate, concentric
striations; the posterior side is not compressed, but has some oblique, faintly marked
striations, which produce a roughened surface where they decussate the concentric
striations.

The specific characters are not strongly defined, and reside more in the general figure
than in the ornamentation of the surface ; the Cornbrash specimens have a thin, shining
test, and the striations can scarcely be distinguished without the aid of a magnifier ; the
posterior side is scarcely so much produced as the other, and the greatest convexity of
the valves is placed a little posterior to the mesial line ; the Kelloway Rock examples
are smaller.

Cardium cognatum is nearly allied to an inferior Oolite species, casts of which are
very common in the Cotteswold Hills ; the latter fossils are more ovate, the muscular
scars more strongly impressed ; the test is much more thick ; the striations, both
concentric and oblique, are more strongly defined, especially the oblique striations

BIVALVIA. 55

upon the posterior side, which deeply indent the shell, and are therefore always
conspicuous. The Cardium cognatwni of Goldfuss is a very different shell, having a
posterior angle and oblique umbones. D'Orbigny (' Prodrome') has arranged our species
with his genus TJnicardmm, in which he has been followed by Dr. Oppel (' Jiu-aformation') ;
but, having examined the muscular impressions and also those of the hinge, I can affirm
that Professor Phillips correctly discriminated the genus.

Geological Podtions and Localities. The specimens figured are from the Cornbrash
of Scarborough ; it occurs also in the Kelloway Rock of the same neighbourhood and in
Wiltshire.

Cardium Witchelij, Li/c. Tab. XL, fig. 36.

Testa parva ovato-trigona, convexa, umbonibus magnis prominentibus medianis, sub-
acutis, latere posferiore atigiilo obliquo et area postica planata, in medio sulco oblique in-
structo ; dorso striis tenuissimis coticenfricis regularibus.

Shell small, ovately trigonal, convex ; umbones mesial, prominent, and somewhat
pointed ; the anterior and lower margins are rounded ; the posterior margin is somewhat
angulated at its lower extremity ; the posterior side has a conspicuous, oblique angle,
separating a flattened, smooth, posterior area, which is traversed by a mesial, oblique furrow ;
the other portion of the surface has very fine, regular, concentric striations. The height
and length are equal ; the diameter through both the valves is somewhat less.

The abruptness of the posterior angle, the flattened, smooth area, with its mesial
groove, appear to separate it from other allied Jurassic species. Possibly it may be a
dwarfed representative of a much larger form.

Geological Position and Locality. The Great Oolite of Bussage, near Bisley Common ;
the process of crushing shelly portions of the white Oolite has yielded this little species
to Mr. Witchell.

Cyphicardia cau data, Lye. Tab. XXXVI, figs. 8, 8 a.

Testa transversa, subtrigoiia, obliqua, subdepressa, umbonibus magnis, elevatis, sub-
involutis, incurvis, latere postico oblique declivi, obtusangulo instructo ; lunula depressa ;
valvis striis longitudinalibus tenuissimis, incequcdibus, latere antico semel striis radiantibus
tenuissimis decussafis. Nucleo striis obscuris radiantibus et concentricis.

Shell transverse, subtrigonal, oblique, rather depressed ; umbones large, elevated, and
subinvolute ; the posterior side slopes obliquely downwards, and has a slightly defined,
obtuse angle ; the anterior side is moderately produced ; the lunule is strongly defined ;

56 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

the lower portion of the anterior border is elliptically curved ; the base is nearly straight ;
the inner borders of the valves are crenulated ; the surface has closely arranged, delicate,
unequal, longitudinal striations, which are decussated upon the anterior side by others
which radiate from the umbones, and when the outer layer of the test has been removed
a series of strongly marked, radiating striations are exposed over the whole of the
valve ; both kinds of striations are also impressed more or less distinctly upon the
nucleus.

This delicately ornamented Cj^'pricardia might at the first glance be mistaken for a
depressed variety of Cy^mcardia cordiformis, Desh., a shell which in the young condition
possesses great difierences of figure ; it will be found, however, that Cypricardia caudafa is
more depressed, more trigonal, the anterior side more lengthened, and the posterior angle
much less defined, so that the portion of the surface posterior to it is even somewhat
convex ; but in Cypricardia cordiformis it is fiattened or often slightly concave in some
instances ; the entire absence of ornamentation, both upon the test and the nucleus, is
another distinctive feature. The fine specimen figured has the area delicately preserved,
and exhibits the ligament ; the test is of moderate thickness, and the inner borders of
the valves are crenulated ; an exposed portion of the nucleus has striations corresponding
to those upon the inner layer of the test.

Geological Position and Locality. The Cornbrash of Northamptonshire j also in the
Forest Marble of Wiltshire, obtained by W. Walton, Esq.

IsocARDiA MINIMA, Sow. Tab. XXXVI, figs. 1, 1 «.

IsocAEDiA MINIMA, Sow. Min. Con., t. 295, fig. 1.

— — Phillips. Geol. York., i, t. 7, fig. 6.

— — Morris. Catal., 1854, p. 204.

— — ? Quenstedt. Der Jura, p. 443, pi. 60, fig. 17.
Non IsocAEDiA MINIMA, Goldf. Pet., p. 211, t. 140, fig. 18.

Testa crassa, loiviyata, tumida, umhonihus parvis submedianis inciirvis, margine dorsali
ohliqne-curvaio, lunula excavata ; lateribus striis concentricis crebris cequalibus, tenuissimis
instructis.

Shell thick, smooth, convex ; umbones small, somewhat oblique, and placed a little
anterior to the middle of the valves ; dorsal border curved obliquely ; lunule excavated ;
the surface of the valves with very delicate, closely arranged, concentric striations.

A smooth, short, rounded, and moderately convex shell, with rather small umbones,
quite difi'erent from the casts figured by Goldfuss and attributed by him to this species,
but which probably belong to the genus Cardium.

The single figure given by Quenstedt is much more inflated, with larger umbones,

BIVALVIA. 57

and is probably also distinct ; it is from a lower geological position, associated with
Trigonia signata, Ag., and other Inferior Oolite fossils of tliat stage.

Another shell erroneously attributed to our species is I. minima, Damon (' Geol.
Weymouth,' SuppL, pi. iv, fig. 7), from the Coral Rag of Weymouth ; it is much more
oblique, with produced umbones.

The figures given in the ' Mineral Conchology' and in the ' Geology of Yorkshire' may
each be objected to for the great prominence of the umbones and the large excavation of
the lunule. The Yorkshire examples, which are very well preserved, differ somewhat from
each other in the degree of their obliquity ; some have a slightly defined, oblique, posterior
angle. The height and length are usually equal, the diameter through the valves being
one fourth less.

Geological Position and Localifij. The Cornbrash of the Yorkshire coast, in which
it is not uncommon.

ISOCARDIA TENERA. Tab. XXXVIII, figS. 5, 5 (7, 5 b.

IsocARDiA TENERA. Gf. Ool. Mouog., t. ", fig. ], part 2, p. G6.
— — Ibid., t. 38, fig. 5, Supplement.

As the figures given in the former portion of this Monograph represent a specimen
deprived of the test, a fine example in a perfect condition is now given, together with a
magnified figure of the ornamentation of the surface. The Cornbrash and the Lower
Calcareous Grit of Yorkshire yield specimens with the test very beautifully preserved,
brown and shining. One from the former rock has been selected ; the valves have delicate,
regular, concentric striations ; and when a portion of the external lamina of the test has
decomposed, the striations are decussated by others radiating from the innbones, as is also
seen in IsocanUa nitida ; these radiating striations belong only to the inner layer of the
test.

IsocARDiA NITIDA, Phil. Tab. XXXVIII,' figs. 6, 6 a, b.

IsocARUiA NITIDA, Phil. Geol. York., i, pi. 9, fig. 10.

— TRIANGULARIS, Bean. Mag. Nat. Hist., 1839, p. 60, fig. 20.

— NITIDA et I. TRIANGULARIS, Morris. Catal., 1854, p. 204.

Testa crassa, nitida, injlata, ovato-trigona, umbonibus medianis, altis, acuminatis, sub-
involutis, latere jjosfico angido oiliquo acuto et area postico subconcavo ; basi postice sinuato ;
valvis striis I'egularibus, longitudinalibus, crebris ; nucleo lavi.

Shell thick, shining, moderately inflated, ovately trigonal ; umbones mesial, elevated,
acuminated, subinvolute ; the posterior side with an oblique, acute angle, which separates

58 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

a slightly concave, posterior area ; the base is sinuated posteriorly ; the sides of the valves
Lave closely arranged, regular, delicate, longitudinal striations. The nucleus is smooth.

The anterior side is more produced and less inflated than Isocardia tenera, Sow.,
from which, also, it differs in having an acute posterior angle. When the external shining
surface has been abraded, it becomes the Isocardia tnanc/ularis of Bean, with radiating
striations, which indent the longitudinal ridges, a feature of which there are analogous
examples in some species of Ceromya, Pecten, &c. The inner border of the valves
is crenulated, and the ultimate stage of growth is distinguished by a deeply grooved,
longitudinal fold.

Length, 14 lines ; height, 11 Hues ; diameter through the valves, 10 lines.

Geolof/ical Fosition and Locality. The Cornbrash of Scarborough, in which it is not
uncommon.

LuciNA STRiATULA, Buv. (var.). Tab. XXXVIII, fig. 7.

LuciNA STRIATULA, Buvignier. Pal^ont. de la Meuse, Atlas, p. 12, pi. 12, figs. 6, 7, 8.

Testa orbiculari, depressa, striis concentricis, fenuibus, interdum majoribiis et striis
radiantibus obsoJefis decmsata ; cardine subbidentato ; imjjressione musculari anteriore
lo7iga, anyusta, poderiore obovata ; imprcssione palleaU nigosa, substriata, sulco obliquo
incm-vo notata. (Buvignier.)

Shell suborbicular, depressed, inequilateral; anterior margin horizontal and nearly
straight; outline of the borders of the valves rather ii-regular; the surface with very deli-
cate, densely arranged, and a few distant, large, concentric striations, decussated by nume-
rous faintly marked, longitudinal lines ; anterior muscular impression lengthened, narrow,
the posterior one obovate ; the pallial impression rugose, with an obliquely curved sulcus.
Height and transverse diameter equal.

The original of our figure is less transverse than that of M. Buvignier, but in other
particulars strictly agrees with it ; it is much less convex then L. rotundata, Roem., and
the surface ornamentation is quite distinct, but the outline of the two species is very
similar.

Geoloffical Positions and Localities. Collected in the Great Oolite of Kirklington,
Oxon., by Mr. Whiteaves. M. Buvignier records it from the Upper Coral Rag of the
IMeuse. Casts which are not uncommon in the Coral Rag of the southern counties of
England appear to belong to the same species.

BIVALVIA. 59

LuciNA ? BuRTONENSis, Lyc. Tab. XL, figs. 20, 20 a, 20 b.

Testa suhorhmdata, depressa, umbonibus subangulatis antrorsim curvatis, latere postico
area depressiuscula, siqoerficie striis tenuibm concentricis crebris notatis.

Shell suborbicular, depressed ; unibones antero-mesial, angulated at their extremities, and
curved forwards ; the posterior side has a depressed, oblique area, without any angle ; the
surface has very delicate, closely arranged, regular, concentric striations ; the hinge-border
is short, and slightly curved.

As the hinge has not been exposed, some doubt may exist whether it is really a
Lucina ; the umbones are more produced than is commonly seen in that genus.

Geological Position and Locality. The Forest Marble of Burton Bradstock, Dorset, in
the collection of W. Walton, Esq.

Lucina Beanii, Bean, sp. Tab. XXXVIIL fi"-. 3

AsTARTE RoTUNDATA, Beati. Mag. Nat. Hist. 1839, non Roemer.

Testa tumida ovato-obliqua, umbonibus antemedianis, magyiis, incurvis, margine cardinali
obhque-declivi, curvafo, margine antico brevi, arcuato curvato ; valvis striis irregularibiis,
plicisque semel instructis.

Shell somewhat inflated, oblique, ovate ; umbones prominent, obtuse, incurved, placed
anterior to the middle of the valves ; hinge-margin lengthened, curved, sloping obliquely
downwards ; anterior margin short, rounded ; lunule very slightly excavated ; the surface of
the valves has irregular, concentric striations, and also a few large plications of growth.
The interior has not been exposed, but neither the hinge-margin nor the anterior border
possesses the usual characters of Astarte, the lunule being nearly obsolete. It is shorter
and more convex than Lucina crassa, nor does it nearly resemble any other contempo-
raneous species.

Height and lateral diameter nearly equal ; diameter through both the valves, one
third less.

Geological Position and Locality. The Cornbrash of Scarborough, in the collection of
Mr. Leckenby.

CoRBis Neptuni, Lyc. Tab. XXXV, fig. 19.

Testa transverse ovali subaquilatera, concentrice costata, margine cardinali curvato,
oblique declivi, lunula magna excavata, umbonibus medianis subdepressis, antrorsum curvatis ;
costis concentricis regularibus ang/istis, striisque interstitiis instructis.

Transversely oval, convex, nearly equilateral ; umbones rather depressed, curved for-

60 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

wards; lumile lai'gc, excavated; hiuge-border curved and sloping downwards; the extremities
are rounded and the base curves eUiptically ; the concentric costas are regular, narrow, ele-
vated, the interstitial spaces having delicate longitudinal striations. The convexity is mo-
derate beneath the uiubones, the extremities of the shell being rather compressed ; the
general figure approaches to C. Leymerii, Buv., but that species has the posterior side
shorter and less rounded. The present shell is more lengthened than is usual with the
Jurassic species, and the concentric costaj are less conspicuous.

Length, 19 lines; height, 12 lines ; diameter through the valves, 9 lines.

Geological Position and Locality. The upper portion of the Great Oolite, near
Minchinhampton, in pale, buflF-coloured Oolite ; few specimens have been obtained, and
these, for tiie most part, are only casts.

Cordis elliptica, Wliiteaves, MSS. Tab. XXXV, fig. 1.

Testa ovato-elongata, dej)ressa, umbonibus parvis medianis, margine antico subhorizon-
tali, postico obliq//e declivi ; bast elliptico curvato ; superfcie rugis longitudinalibus regu-
laribus, magnis, elevatis, crebris.

Shell ovately elongated, rather depressed ; umbones small, but little elevated, mesial ;
anterior margin nearly horizontal ; posterior margin sloping obliquely downwards ; the two
extremities of the shell are rounded, and the base is curved eUiptically ; the surface is orna-
mented with large, elevated, longitudinal, regular, and 'closely arranged rugas.

Length, 1\ lines ; height, half the length.

A small, depressed, and unusually lengthened Corbis, which will not readily be mis-
taken for any other known Jurassic species.

Geological Position and Locality. The Forest Marble of Kidhngton, Oxon., collected
by Mr. Whiteaves.

CoRBis ROTUNDA, Walton, MSS. Tab. XL, fig. 17.

Testa crassa, ovato rotundata, umbonibus magnis medianis antrorsum curvatis, lateribus
stib-ceqnalibiis postice subcompressa, siipcrficie rugis conccntricis magnis, crebris, sub-
cequalibus ; atate adulto rugis obaoletis ; cardo dente antico laterali magna.

Shell thick, ovately orbicular, subglobose ; umbones large, mesial, curved forwards ; the
sides nearly equal, but the posterior side is slightly compressed and shortened ; the surface
with large, closely arranged, concentric, but somewhat unequal rugae, which degenerate in
the adult state and nearly disappear.

It has sometimes been mistaken for Sphcera Madridi, but it is more orbicular, and the

BIVALYIA. 61

umbones are larger ; the concentric rugae will also at once distinguish it, as the young shell
of S. Madridi is smooth.

Geological Positions and Localilies. The Great Oolite of Hampton cliffs ; the Corn-
brash of Laycock. In the collection of W. Walton, Esq.

Opis Leckenbyi, Wright. Tab. XXXVII, figs. 9, 9 a.

Opis Leckenbyi, Wright, iii Proc. Geol. Soc, vol. xvi, part 1, 1860.

Testa crassa, trigona, oUiqiia, fornicata, in<Equilafem, cordiformi, transverse regulariier
cosfafa, posfice acute carinata, umbonibus magnis elevatis, anticis, involutis, latere antlco
brevissimo, postico subrecfo oblique declivi ; lunula magna profunda, marginibus obtusis,
striatis ; costis tra?isversis, regularibus, angmtis, subacutis ; valvis striis longitudinuUtms et
decmsantibus subtillissimis instructis.

Shell thick, trigonal, oblique, very convex, and inaequilateral, cordiform, with transverse,
regular costae ; a large, flattened, posterior area is separated from the other portion of the
shell by an elevated, acute carina, anterior and parallel to which is a slight depression ; the
umbones are large, elevated, much inclined forwards, and involute ; the anterior side is
very short, having a large and deep lunule, whose margin is rounded and striated ; the
costse upon the sides of the valves are regular, narrow, subacute, and not much elevated ;
the wide, posterior area has large, oblique striations ; the costated portion is covered with
extremely fine perpendicular and decussating striations, which are only distinguishable
under a magnifier.

Height, 15 lines ; length, 15 lines ; diameter through both the valves, 13 lines.

A large and elegant species, distinguished from Opis lunulatus. Sow., by the more con-
vex figure, the rounded margins of the lunule, and by the more acute and more densely
arranged costse; the posterior carina and bordering sulcation are also very prominent
features ; the costse under a magnifier exhibit a beautifully decussated surface.

Geological Position and Locality. The Cornbrash of Scarborough ,- a single specimen
in the collection of Mr. Leckenby.

Opis pulchella, B'Orb. Part II, Tab. VI, fig. 3, p. SO.

Opis pulchella, I)' OrhUjny . Prodrome, i, p. 307.
— LUNULATUS, var. Great Ool. Mod., Pal. Soc, part 2, pi. 6, fig. 6, p. 80.

Espece voisine de V 0. Immlafa, mais bienplus courte et moins oblique, presque carree
ornee de cotes concentriques." (D'Orbigny.)

The experience derived from a multitude of examples leaves no room to doubt that the

62 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Minchinharapton Opis allied to 0. lunulatus is distinct from the typical Liferior Oolite
shell, and that D'Orbigny has correctly indicated its distinctive characters in the brief
sentence above quoted ; our figures in Part II, Tab. VI, faithfully represent the Great Oolite
species.

Opis Luciknsis, B'Orb. Tab. XL, figs. 19, 19 a.

Opis Luciexsis, D'Orbigny. Prodrome, i, p. 307, No. 106.

Testa subtrigona, postlce acute carinata, mnbonibus prominentibus acutis, lunula per-
magna, profunda, Icevigata, in/erne rosfrata, area posteriora sulco obliqiio itistructo ;
superjicie slriis tenuibus concentricis, i/iferchim obsoletis.

Shell subtrigoual, short, posteriorly acutely carinated, with a conspicuous, oblique sulcus
upon the post-carinal area ; the umbones are elevated, acute, moderately incui'ved ; the
lunule is very large and deeply excavated, occupying the entire anterior side ; the surface
is smooth, with an acute, plain margin, its lower extremity forming a rostrated projection ;
the posterior surface of the valves has very delicate, concentric striations, which are only
partially visible.

It is allied to 0. pulchella, but is shorter, less convex, the umbones are more prominent
and less incurved, the lunule is very much larger, the posterior keel more acute, the
surface more smooth.

Geological Position and Locality. The Great Oolite of the Box Tunnel, near Bath, in
the collection of W. Walton, Esq.

CoRBULA ATTENUATA, Lyc. Tab. XXXVII, figs. 0, 6 a.

Testa convexa, parva, subcsquilatera, transversa, longitudinaliter, subtillissime striata ;
latere posteriore attenuato, rostrato, producto ; aiigulo obliquo itistructo ; basi leviter
curvato, postice subsinuato.

Shell small, convex, nearly equilateral, transverse, longitudinally very finely striated ;
anterior and posterior borders sloping ol^liquely downwards; the posterior side is attenu-
ated ; it has an oblique angle, which separates a narrow posterior space ; its lower extremity
is rostrated i the anterior lower extremity is elliptically curved; the lower border is
lengthened, slightly curved, and posteriorly somewhat sinuated; the umbones are small and
somewhat pointed. The figure is more elongated and has less convexity than the other
Great Oolite species of the genus ; the striations upon the posterior slope are bent
upwards at a right angle to their direction across the valve.

Height, equal to two thirds of the length, and a third greater than the diameter through
both the valves.

BIVALVIA. 63

Geological Positions and Localities. This well-marked little Corbula has been kindly
forwarded by J. F. Whiteaves, Esq., from the Great Oolite of Kirklington, Oxon. ; also by
W. Walton, Esq., from the Forest Marble of Laycock, Wilts.

Corbula involuta, Munsf. Tab. XXXVII, figs. 4, 4 a.

Corbula involuta, Goldf. Pet., t. 151, fig. 14.
Cyprina — D'Ori. Prodrome, i, p. 2/8, No. 309.

Testa crassa, parva, 2:)ennflata ; concentrice suhtillissime striata ; umbonibus magnis
obtiisis, submedianis ; latere antico rotmulo, jwstico rostrafo, obtuse carinato et attenuato.

Shell small, thick, greatly inflated, with very delicate, concentric striations ; umbones
large, obtuse, submesial ; anterior side short, rounded, posterior side attenuated, rostrated,
its margin concave, and forming at its lower extremity an acute angle ; the posterior slope
has delicate, transverse striations; it is somewhat flattened, very narrow, and is only
obscurely separated from the dorsal portion of the shell by an obtuse angle ; the lower
border is nearly straight.

Length, one third greater than the height and the diameter through both the valves.

The foregoing description will serve to distinguish it from a small, thick, but less in-
flated species, abundant in the Great Oolite of Minchinhampton, and which was formerly
regarded by me as C. involuta of Munster, and figured under that title in Part II, Tab. VI,
of the ' Great Oolite Monograph,' and described in Part II, p. 97 ; it had previously
been figured and described by Professor Buckman, in Sir R. INIurchison's ' Geology of
Cheltenham,' 2nd ed., p. 97, pi. 3, fig. 4, under the title of Corbula striata ; but as that
name had already been appropriated by Lamarck for an Eocene Corbula, it becomes
necessary to change it to C. Buckmani, under which name it is refigured. Tab. XXXVII,
fig. 8, thrice magnified.

Geological Position and Locality. The Great Oolite of Kirklington, Oxon. ; collected
by J. F. Whiteaves, Esq.

Corbula Islipensis, Lye. Tab. XXXVII, fig. 7.

Testa parva, infata, iimbonibus medianis, magnis, erectis, latere anteriore rotundo,
j)osteriore brevi, abrupte truncato, angulo oblique instructo ; valvis longiiudinaliter striatis,
striis magnis regularibus, lineis angustis separatis ; lunula excavata ; basi subrecto.

Shell smalt inflated, but subquadrate or cuculseform ; umbones large, mesial, erect ;
anterior side rounded, its lunule excavated; posterior side short, abruptly truncated, with
an oblique and subacute angle separating a posterior smooth and slightly concave
area; the lower border is nearly straight; the dorsal surface has large, regular.

64 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

longitudinal striations, separated by elevated, narrow lines, which disappear at the posterior
angle.

The height, length, and diameter through the united valves are nearly equal; the test
is thick.

The shortness of the posterior side, its angle, and the greater prominence of the
urabones, will distinguish it froru C. striata, Buck. (C. Buckmanii, nobis, PI. XXXVII,
fig. 8). Corbida iiivoluta, Munster, has the posterior side more lengthened and
rostrated, and is almost destitute of the posterior angle ; the striations upon the surface
are much more delicate and faintly traced, they are oblique rather than concentric or
longitudinal. Corhula cucutceformis, Kock and Dunker, is also allied to it, but with the
figure less inflated and with more pointed umbones ; it is therefore, probably, distinct.
Possibly C. amata, D'Orb., may be identical with our species, but unfortunately the few
words of description in the ' Prodrome ' of that author are insufficient to characterise it ; the
same remark will also apply to his C. Aglaya and C. Alimcna.

Geological Position and Locality. The Bradfordian beds of Islip, Oxon. ; collected by
J. P. Whiteaves, Esq.

CoRBULA HuLLiANA, Mor. Tab. XXXVII, fig. 5.

CoRBULA HuLLiANA, Morris. Hull. Mem. Geol. Surr., Cheltenham, 1857, pi. l.fig. 6.

Testa crassiicscula, inflata, ovato-trigona, subcequivalvi, suhaequilaterali, antice prodticta,
rotunda, postice atienuata, sulco obliquo et carina marginali obtuse; umbonibus magnis
sribacutis incurvis ; basi subarcuato aut subrecto ; lateribus costis obliquis angustis, elevatis,
regiilaribus postice undulafis ; striis radianfibus decussatis.

Shell of moderate thickness, much inflated, ovately trigonal, subajquivalve, subaequi-
latei'al; umbones large, iaicurved, and pointed ; anterior side produced and rounded, posterior
side more attenuated, with an oblique groove and submargiiiul, obtuse, rugose keel, the
base arcuated, or in other specimens nearly straight and slightly irregular ; the surface of
the valves with prominent, oblique, regular, narrow costae, which are slightly undulated
posteriorly ; occasionally the left valve exhibits towards the middle of its lower portion a
few perpendicular striations, which decussate the costs; and render the lower margin
dentated.

The largest of the British Oolitic Corbulse, with the hinge -characters strongly marked;
the valves are less thick than usually obtains in the genus ; it is also apparently equivalve ;
a well-preserved specimen of the left valve is destitute of the perpendicular striations.

Geological Position and Localities. The specimen figured in the ' Memoirs of the
Geological Survey of Great Britain' was obtained in the Forest Marble near to Northleach ;
it occurs in the same position at HintoU; at Farleigh, and at Kidlington, Oxon., specimens

BIVALVIA. 65

have been forwarded to mo by Mr. Walton and by Mr. J. F. Whiteaves ; at the Oxford-
shire locality, the specimens are small and usually compressed.

CoRBULA Agatha, DOrh. Tab. XL, figs. 28, 28 a.

CoRBULA Agatha, B'Orb. Prodrome, i, p. 307, No. 100.

Testa parva, suhglolosa, lavigata, nitida, umbonibus magnis, obtusis, med'mnis, eredis,
latere anteriore rotunda ; lunula magna, concava, cordata ; latere postcriore brevi, sub-
carinata, truncata.

Shell small, globular, smooth, shining ; umbones large, obtuse, mesial, erect ; anterior
side rounded, lunule large, cordiform, concave ; posterior side very short, with a faintly
marked oblique carina, and a truncated posterior border ; the surface has a few delicate,
irregular folds of growth ; it appears to be equivalve.

The diameter through both the valves is equal to the height, and somewhat less than
the length.

Corbula Beshaysea, Buv., is also a smooth species, but less short, the posterior border
being also slightly sinuated. Corbula Mameillii, Mor., another smooth shell, is much
more oblique, and more produced posteriorly. Corbula obscura, Sow., appears to be less
convex, and to have the posterior side more produced.

Geological Position and Locality. The Forest Marble of Cirencester and of
Wiltshire.

Genus — Sowerbya, L' Orb., 1850.

IsoDONTA, Buv. Bull. Soc. Geol. de Fr., ser. 2, t. 8, p. 353, 1851.

Shell equivalve, subequilateral, the valves close fitting ; hinge in the right valve, with
two oblique, diverging, symmetrical cardinal teeth separated by a mesial trigonal pit, and
two lamellar lateral teeth separated from the hinge-border by longitudinal grooves. The
left valve with a projecting conical tooth between two oblique pits ; lateral teeth two,
longitudinal, lamellar, projecting and united to the superior border. Ligament external.
Muscular impressions small, rounded, deeply marked ; palleal impression emarginated
posteriorly.

M. D'Orbigny in his 'Prodrome de Paleontologie,' vol. i, 13 Et., p. 362, characterised
his genus Sowerbya as follows : — "Sowerbya, D'Orb., 1847. — Coquille voisitte des Mactra
par son sinus, mais avec des dents lateralcs enormes, et une fossette interne ligamentaire
simplement creusee."

9

66 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

It appears from the above quotation that M. D'Orbigny was acquainted only with
the hinge of the right valve of his Soioerhya crassa, upon which species the genus was
founded, and that he mistook the mesial dental pit for a fosse destined to receive an
internal ligament. In 1851, M. Buvignier having worked out the details of the generic
characters from specimens obtained in the upper ferruginous Oolite of the Oxfordian
strata of Ornes (Mense), and Launoy (Ardennes)^ gave them to the public in the ' Bulletin
of the Geological Society of France,' ser. 2, t. 8, p. 353, under the new generic
designation of Isodonta. It is to the researches of M. Buvignier, therefore, that we are
indebted for a full and accurate description of Soioerbya. The same author states that
M. Terquem has discovered one nearly allied to the typical form in the Bradfordian beds
of the Mozelle.

The Jurassic rocks of England contain upwards of five species of Sowerbya : — 1,
8. triavgularis, from the Oxfordian and Lower Oolites of Yorkshire ; 2, 8. Woodwardi,
from the Great Oolite of the Minchinhampton district ; 3, a small abruptly truncated
species from the Coral Rag of Yorkshire and Oxfordshire ; 4, a small subsequivalve shell,
with a posterior strongly marked oblique angle from the Coral Rag of Bullingdon ; 5, an
internal cast of a large species determined by Mr. Woodward, and figured by Mr. Damon
in his ' Geology of Weymouth,' from the Portland Oolite, under the name of 8. Diikei.

Sowerbya triangularis, P/dL, sp. Tab. XXXV, figs. 3, 3 a, 3 b.

CucuLL/EA TRIANGULARIS, Phil. Geol. York., i, pi. 3, fig. 30.
Arca triangularis, D'Orb. Prodr., i, p. 369.
CucuLL.DA TRIANGULARIS, Mor. Catal., 18.34, p. 197.

Tesfa transverse, ohlonga, injlafa, subcequilafera, postice oblique carinafa, umbonibus
parvis postero-medlanis, marguie inferiore anyulo formante ; superficie plicis longitudi-
nalibus paucis magnis et stri'is longitudinalibus subtillissimis ornafa.

Shell transverse, oblong, inflated, slightly inaequilateral ; the posterior side the shorter,
with a posterior oblique angle, separating a posterior slightly excavated surface which
terminates downwards in a conspicuous angle ; the anterior side is produced and cur\'ed
elliptically ; the umbones are placed a little posterior to the middle of the valves ; they are
small and contiguous. The surface has one or two large folds of growth, and is orna-
mented with longitudinal, regular, closely arranged striations, which disappear upon the
posterior excavated slope.

The height is about equal to the diameter through both the valves, and to three fifths
of the length.

The species exhibits much variability in the general figure, in the degree of convexity,
in the prominence of the posterior angle, and in the length ; differences which are not
limited to a single formation or locality, as it occurs in the Yorkshire Oolites in the

BIA^ALVIA. 67

Dogger, the Gray Limestone, the Cornbrash, the Kellovvay Rock, and the Coral Rag ;
numerous specimens are also in the Tessonian collection from Normandy, now in the
British Museum. Some of these examples are almost destitute of the posterior angle, and
approach so nearly in the general figure to Sotoerhya crassa, D'Orb. = Tsodoiita Dcs-
luijjsea, Buv., that they might fairly have been assigned to that species, if we had not the
assurance of ]\I. Buvignier that his specimens from two localities are in a good state of
preservation, and that they are destitute of ornamentation — a feature which is always dis-
coverable in good examples of 8. triangularis, whether British or Foreign.

Mr, Whiteaves has figured a small species of Sowerbya, ' Ann. and Mag., Nat. Hist.,'
August, 186], under the name of S. triangularis, Phil. Having had the advantage of
comparing the original specimen, through the kindness of Mr. Whiteaves, with various
Yorkshire specimens of S. triangularis, I feel unable to coincide in the opinion that it is
identical with the species of Professor Phillips ; the new Oxfordshire form is much
smaller, less inflated, destitute of ornamentation ; and the posterior side is so short that
' truncata would be an appropriate name : it is from the Coral Rag of Oxfordshire. I
have also found it in the Calcareous Grit at Scarborough Castle.

The second small species figured by Mr. Whiteaves upon the same plate under the
name of 8. Beshaysea, Buv.? also appears to be distinct from each of the foregoing
examples ; the general figure is more compressed, the anterior slope is excavated,
which renders its lower extremity pointed ; the whole aspect somewhat resembles a
Nucula.

Our specimen figured is from the Cornbrash of Scarborough.

SowEEBYA WooDWARDi, Lyc. PI. XL, figs. 27, 27 a, 27 b, 27 c.

Testa ovato-triyona sutjdepressa, subcequilatera, latere posteriore breviori, planata,
laevigata angulo obUqiio diviso, dorso et latere antico striis longitudinalibiis regularibus
crebris, delicate instructis.

Shell ovately trigonal, rather depressed, subequilateral, the posterior side being the
shorter; the umbones are not very prominent nor large; the anterior and posterior borders
slope obliquely downwards ; the extremities of the valves are rounded ; the surface has
delicate, closely arranged regular longitudinal or concentric striations, which are separated
from the smooth and flattened posterior side by a distinct angle.

It is much smaller, more depressed, more lengthened, and the umbones are much less
elevated than in ^S*. triangularis. Our right hand figure is imperfect at the posterior
extremity, and the posterior oblique angle is not clearly shown ; the left hand figure
has the anterior extremity too obtusely rounded, the specimen wanting a little of its
border.

Geological Position and Locality. The Great Oolite of Bussage, near to Bisley

68 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Common, collected by E. Witchell, Esq. A specimen has also been brought under my
notice by S. P. Woodward, Esq., but its locality is uncertain.

Tancredia gibbosa, Lye. Tab. XXXV, fig. 7. Tab. XXXVI, fig. 11.

Tancreda gibbosa. Lye. Cott. Hills Handb., p. 121, pi. 7, fig. 4.

Testa snbtriffona, tumidula, umhonibus medianis acutis, latere antico attenuato, pustice
tuinido subangulato ; dorso lcBvigato,plicis incrementi , paucis irregidaribus.

Shell subtrigonal, tumid ; umbones elevated, pointed, and placed a little anterior to the
middle of the valves ; the anterior side is rather attenuated and pointed at the lower
extremity ; the posterior side slopes obliquely downwards, it is somewhat tumid, and has an
oblique angle slightly defined ; the siu-face is smooth, but with a few plications of growth
towards the lower border.

Height, 10 lines; length, 13 lines; diameter through both the valves, 6 lines.

It is distinguished from other Great Oolite species by the combination of a trigonal
outline with a tumid figure.

Geological Positioii and Locality. It occurs rarely in the Great Oolite shelly
weatherstones of Minchinhampton Common, and the Forest Marble of Farleigh,
Somerset.

TANCRiiDiA MACTR^oiDES, Whiteaves, MSS. Tab. XXXV, fig. 4.

Testa ovato trigona, convexa, umbonibus submedia7m elevatis, iticurvis ; margine antico
Ijreviore, Icevitcr excavato, margine postico oblique declivi, angulo oblique laviter instructo,
basi ellijitico ciirvato.

Shell ovately trigonal, convex, with a few concentric plications ; umbones antero-
mesial, elevated, and incurved; anterior border the shorter, slightly concave; the extremity
pointed ; posterior hinge-border sloping obliquely ; there is also a posterior oblique angle
faintly marked.

lancredia gitjbosa, Lye, approximates to this species, but is more convex, with a more
elevated and rounded posterior slope. T axiniformis, Phil., from the Inferior Oolite of
Yorkshire, is more flattened, with more pointed umbones and acute posterior angle.
Height two thirds of the length.

Geological Position and Locality: The Great Oolite of Stonesfield, Oxon., where it
appears to be rare ; collected by J. F. Whiteaves, Esq.

Tancredia similis, Whiteaves, MSS. Tab. XXXV, fig. 9.

Testa ovato clongata, umbonibus antemedianis, latere antico attenuato, breviore ; postico
convexo, angulo obtuso obliquo ; basi elliptica curvata.

BIVALVIA. 69

Shell ovately elongated ; umbones placed anterior to the middle of the valves, rather
depressed and obtuse ; anterior side the shorter, its upper margin slightly excavated, its
lower extremity pointed ; posterior side larger, more convex, with an oblique obtuse angle ;
the hinge-border is moderately lengthened and horizontal ; the surface is smooth, the lower
border is elliptically curved.

T. extensa. Lye, ' Gr. Ool. Mon.,' p. 93, approximates to the present form, but has a
much larger anterior side, with the umbones more elevated and mesial.

The height slightly exceeds half the length.

Geological Position and Locality. The Great Oolite of Kirklington, Oxon., collected
by Mr. Whiteaves.

CORBICELLA SUB^QUILATERA, Lyc. Tab. XXXV, fig. 12.

CoKBiCELLA suB^quiLATERA, Lycett. Cotteswold Hills Handbook, p. 126.

Testa ovato-obliqua laevigata, unibonibus parvis, antero-medianis, lunula angusta, sulco
ligamenti angusto, margine superiore oblique curvato.

Shell oblique, ovate, smooth ; umbones not prominent, placed a little anterior to the
middle of the valves ; anterior border slightly depressed, lunule narrow ; superior border
curved obliquely ; ligamental sulcus narrow and lengthened ; surface of the valves smooth,
the lines of growth being only faintly impressed. The height is equal to two thirds of
the length ; the diameter through both the valves is equal to about half the height.

This shell presents an example of a remarkable series of Jurassic bivalves, whose cha-
racteristic features are intermediate between Corbis and Tancredia, and which may usually
be discriminated without reference to the hinge ; compared with Corbis, the more depressed
form, the smallness of the anterior side, and the surface destitute of ornament, will always
distinguish it ; from Tancredia by the more ovate form, and by the absence of the posterior
oblique angle. The hinge is figured upon PI. XII, fig. 15, of the ' Great Oolite Monograph ;'
but the artist has scarcely extended the hinge-lamina sufficiently to exhibit the depressed
posterior lateral lamellar process ; the absence of the anterior lateral tooth, and the figure
of the cardinal dentition, is also distinct from Corbis, and is more nearly allied to Tancredia,
from which it differs chiefly in possessing a lengthened hinge-lamina and depressed
remote posterior lateral tooth; these distinctive features are remarkably persistent in
every example of Corbicella, and tends greatly to strengthen its claims to a generic
distinction.

Under the name of Corbis lucida our species was included in Mr. Bean's list of
Cornbrash Fossils, published in the ' Magazine of Nat. Hist.,' 1839, but was not accom-
panied by any figure or description.

Geological Positions and Localities. The specimen figured is a fine example from the

7U SUPPLEMENT TO GREAT OOLITE MOLLUSC A.

Cornbrash of Scarborough, in which rock it is rare. The lower grit of the upper portion
of the Inferior Oolite at Rodborough HUl, near Stroud, has produced a considerable
number of specimens, for the most part smaller, and sometimes more nearly equilateral ; it
also occurs in the same position at Leckhampton Hill ; at each of these Inferior Oolite
localities it is associated with a larger, more lengthened, aud more depressed species.
(C. co7nplanata. Lye). Corbis depressa, Desh., from the Oxfordian strata of Viel,
St. Remy, approaches nearly to it in the general outline, but is more depressed and some-
what less ovate.

CORBICELLA SUBANGULATA, LyC. Tab. XL, fig. 9.

Testa ovata suh-com2}ressa, transversa, umhonibus antemedianis, mediocri viaffnitudine,
maryine cardinali oblique declivi, latere postico angulo oblique imtructo, marline antico
subconcavo, svperficie plicis incrementi magnis irregularibus.

Shell ovate, somewhat depressed, transverse ; umbones of moderate size, placed anterior
to the middle of the valves ; hinge-border of moderate length, sloping obliquely down-
wards ; the posterior side has an oblique angle ; the anterior border is slightly concave ;
the surface has numerous plications of growth, which become large and irregular towards
the lower border.

Allied to C. complanata. Lye, from which it is distinguished by the strongly marked
posterior angle, and by the larger umbones ; our specimen is imperfect at the posterior
extremity.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

Cyprina Islipensis, Lye. Tab. XXXV, fig. 13.

Testa ovato-transversa, convexa, Icpvi, obliqua, umbonibus antemedianis magnis,
incurvis, lunula magna, excavata, area parva lanceolata ; latere postico compresso, angulo
obliqno formante ; basi elUptica curvala ; striis conccntricis tenuibus, irregularibus,
subobsoletis.

Shell ovately transverse, convex, smooth, oblique ; umbones large, incurved, placed
anterior to the middle of the valves ; area small, lanceolate ; posterior side compressed and
slightly concave, forming an oblique and well-defined angle with the other portion of the
surface ; lower border curved elliptically, forming an angle at its junction with the posterior
border. Nearly alUed to Cyprina Loweana, Mor. and Lye, from which it is distinguished
by the larger umbones ; larger lunule, by the posterior flattened or concave area, and by
the well-defined oblique and acute angle, which renders the posterior extremity some-
what rostrated.

BIVALYIA. 71

Geological Positions and Localities. The specimen figured was obtained by
Mr. Wliiteaves in the Great Oolite of Kirklington, Oxon. ; it has also occurred rarely in the
same formation at Minchinhampton Common, and in the Cornbrash of Islip, Oxon.

Cyprina BELLA, Li/c. Tab. XL, figs. 15, 15 a.

Testa ovato-orbiculari Itevigata, suhdepressa, nmhonibus mediocris, antero-medianis,
marline cardinali recto, suhhorizontali, postice suhangulata, lunula angusta vix depressa ;
superficie angulo postico obliqito instructo ; striis incrementi crebris, irregularibus.

Shell transverse, ovately orbicular, smooth, rather depressed ; umbones of moderate
size, but little elevated, placed a little anterior to the middle of the valves and curved
forwards ; hinge margin straight, nearly horizontal, and slightly angulated posteriorly ; the
lunule is narrow, and but slightly impressed ; the exterior surface has an oblique angle,
posterior to which the surface is flattened ; the striations of growth, and delicate, numerous,
and irregular.

The depressed form, posterior subhorizontal straight hinge border, and oblique
posterior angle, are the features that will serve to distinguish it from allied contemporaneous
forms. The numerous specimens placed at ray disposal include examples from two to
nine lines in length, which measurements usually exceed the height by one fifth.

Geological Position and Localities. The Forest Marble of Laycock and Pound Pill.
In the collection of W. Walton, Esq.

Cyprina Davidsoni, Lye. Tab. XXXVI, figs. 6, C a.

Testa ovato-orbiculari crassa, convexa, obliqua, umbonibus obtusis submedianis antrorsmn
injlectis, marginibus arcuatis curvatis, latere postico area subplanata, angula obtmo obliqiio
interdum instructo, aui nullo ; lunula vix excavata, inconspicua, superficie striis concenfricis
irregularibus.

Shell ovately orbicular, thick, convex, oblique, but varying much in the length and
obliquity ; umbones obtuse, submesial, directed forwards ; margins of the valves curved
eiliptically and close fitting, lunule not conspicuous and scarcely excavated ; the posterior
side has a narrow, oblique, flattened space, sometimes separated from the other poi'tion of
the surface by an obtuse angle ; in other instances there is no distinct angle ; the surface
has numerous irregular concentric and faintly marked plications.

Dimensions of a large specimen of medium figure; length, 17 lines j height, 15 lines ;
diameter through the valves, 1 1 lines.

It is liable to be mistaken for Cyprina Loioeana, compared with which our shell is

72 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

shorter, more convex, the test thicker, the umbones larger, less ol)lique, and more obtuse ;
the posterior flattened area is also a distinguishing feature when it is present.

Geological Position and Localities. The Porest Marble of Laycock and Farleigh, in
the collection of W. Walton, Esq., of Bath.

ASTARTE UNGULATA, Phil., sp. Tab. XXXV, fig. 20.

AsTAKTE LUBiDA, Ptiil. Geol. York., i, pi. 5, fig. 2, p. 137, non A. lurida. Sow.

— — Williamson. Trans. Geol. Soc, 2d ser., vol. vi, p. 149.

— — Bean, on Cornbrash Fossils, Mag. Nat. Hist., 1839.

— — Leckenby, on Kelloway Rock Fossils, Journ. Geol. Soc, 1858.

I'esfa suborbiculari aut suhquadrangulari, depressa, incequHatera, ad peri])h(jeriam con-
centrice costellata, costellis elevatis, subangularibus, concentrice subtil lissime striatis ;
costellii inferne evanescentibus ; margine cardinali curvato, lunula subnulla.

Shell suborbicular or somewhat subquadrangular, depressed, inequilateral ; umbones
small and only slightly produced ; posterior and inferior margins rounded, lunule,
obsolete ; the surface near to the umbo with elevated acute concentric rugfe, which are
impressed with very delicate concentric striations ; the rugfe disappear towards the middle
of the valve, the lower portion having only some plications of growth.

The character of the surface has a considerable resemblance to Astarfe JViltoni, ' Gr.
Ool. Monogi-.,' Tab. IX, f. 16 ; but the latter has the umbo much more produced, it has a
distinctly excavated lunule and is more convex ; other depressed species are sufficiently
separated by their ornamentation.

Astarte lurida. Sow., which occurs in Gloucestershire at Nailsworth in gray shale
near to the upper boundary of the Upper Lias, and in the lower portion of the overlying
Supraliassic Sands associated with Ammonites variabilis, is a very different shell, whose
figure is ovately trigonal and moderately convex, with prominent apex, well-marked lunule
and depressed concentric rugae ; it does not therefore present a near approximation to our
species.

Astarte vngulata has the height and lateral diameter equal ; the valves are moderately
thick ; the size varies from 4 to 10 lines across. It is rare.

Geological Positions and Localities, Professor Phillips figured the interior of a valve
from the Oxford Clay of Scarborough. Mr. Leckenby has recorded it in the Kelloway
Rock of the same locality ; our figure is taken from a Cornbrash specimen of the same
coast now in the collection of Mr. Leckenby, and formerly in that of Mr. Bean, who
identified the species M'ith that originally figured in the ' Geology of Yorkshu'e.'

BIVALVIA. 73

AsTARTE ORBICULARIS, Sow. Tab. XL, fig. 33.

AsTARTE OKBiciLAEis, Sow. Min. Con., v, p. 65, tab. 44-4.

— — Morris. Catal., p. 187.

— — B'Orb. Prod, de Paleont., i, p. 308.

Testa parva Hiiborhiculari, convexa, umbonihus mediants elevatis, lunula inat/7ia, valvis
coslulis concentricis numerosis, depressis, intersfiis latioribus, subaqualibus.

Shell small, nearly orbicular, convex ; unibones mesial and produced ; lunule distinctly
marked, rounded, the surface with nuuierous (about twenty) depressed, narrow, con-
centric little ribs, separated by somewhat wider and nearly equal spaces, upon the posterior
side the ribs are slightly undulated.

The little ribs are strongly marked upon the sides, but much less so upon the middle
of the valve, and are scarcely to be distinguished upon the umbones ; they are so delicate
that the surface appears plaiu without the aid of a magnifier; this latter feature will
serve to distinguish it from other small species, as A. minima, Phil., A. jjisifonnis, Sow.,
A. Farkinsoni, Quenst. Of other small examples of the genus, A. pisum, Kock and
Dunker, and A. I'onionis, hyc, are much less orbicular, and have more prominent costse ;
A. mediolavis, Buv., has the ornamentation of a similar character, but the figure is ovately
trigonal, and therefore sufiiciently distinct.

Geological Positions and Localities. The upper beds of the Great Oolite near Bath,
where it appears to be not uncommon ; also upon the same horizon at Ancliff, Wilts.
Luc (Calvados).

AsTARTE POLiTULA, Bean. Tab. XXXV, fig. 16.

AsTARTE POLITULA, Bean. Mag. Nat. Hist., 1839.

Testa suborbiculari, convexo-plana, umbonibus antemedianis parvis, acutis, incurvis,
viarffine cardinali curoato, fossa tigumenti, angiisto, elonyato, margine antico sutjrecto
lunula lanceolata, leviter excavato ; valvis striis regularibus tenuissimis concentricis, inferiore
irreffulariter plicatis.

Shell suborbicular, rather depressed ; umbones anterior to the middle of the valves,
small, acute, incurved ; hinge-border slightly curved ; ligaraental groove narrow and
lengthened ; anterior border nearly straight ; lunule lanceolate and slightly excavated, its
margins subacute ; the surface of the valves with very fine, regular, concentric striations ;
the lower portion of the surface is destitute of striations, but has several irregular, con-
centric plications.

The convexity is moderate about the middle of the valves, but the test has not much

10

74 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

thickness towards the borders, the oiithne has a considerable resemblance to Lucina
crassa but the latter is much thicker towards the borders of the valves, and has a different
kind of surface. The hinge has not been exposed.

Geological Position and LocaUti/. The Cornbrash of Scarborough ; in the collection
of ]\Ir. Leckenby.

AsTAKTE Leckenbyi, WriffJd. Tab. XLII, fig. 3.

Testa erassa, transversa, ovafa, suhdeprcssu, umbonihus parvis, prominulis antero-
medianis ; latere antico brevi, marr/ine rotundo, lunula suhnuUa ; latere jjostico producto,
margine superiori subrecfo, elongato, oblique decHvi ; basi arcuato curvato ; superficie
ru(/is crebris concentricis et striis subtilibus ornatis.

Shell thick, transverse, ovate, rather depressed ; umbones small, prominent, placed at
the commencement of the anterior third of the shell ; anterior side short, its margin
rounded with scarcely any lunule ; posterior side produced and compressed, its superior
margin nearly straight, lengthened, sloping obliquely; the base is elliptically curved; the
surface has prominent, concentric, closely arranged, rounded rugas near to the umbones,
which afterwards degenerate into depressed, irregular plications ; there are also fine, con-
centric striations.

A large species, remarkable for the depression of the valves and for the great
length and straightness of the superior border, whose measurement is equal to the
height or to two thirds of the entire length of the shell ; the rugae are so closely
arranged near to the apex that upwards of thirty may be counted upon one fourth the
height of the shell.

From Astarte elegans, Sow., it is distinguished by the more lengthened, depressed
figure, and by the absence of a smooth, excavated lunule ; it is much less orbicular and
convex than A. detrita, Goldf. ; the depressed figure, lengthened, straight, upper margin,
aud large rugae, will serve to distinguish it from other large ovate species of the lower
Oolites. S[)ecimens in Mr. Leckenby's collection exceed three inches in length. It is
not rare, Ijut, in common with other large shells of the Cornbrash, it has usually undergone
compression.

Geological Position and Locality. The Cornbrash of Scarborough, in hard, gray
limestone.

AsTAKTE ROBUSTA, Lyc. Tab. XXXV, figs. G, 6 a.

Testa imrva suborbiculari, perinjlata, imbonibus magnis medianis incurvis, margine
posteriore et inferiore rotundo, lunula magna concava marginibus rotundis ; valvis costis

BIVALVIA. 75

concentricis, regularihus, angustis, elevafis (16 — 18) striisque suhtillisshnis, concentricis,
impressis.

Shell small, suborbicular, much inflated ; umbones large, mesial, incurved ; posterior and
lower margins rounded ; lunule very large, concave, its margins rounded ; the surfaces of
the valves have narrow, concentric, regular, elevated costae, 16 — IS in number, which are
impressed by very delicate concentric striations ; the intercostal spaces are upwards of three
or four times the breadth of the costa.

Height, lateral diameter, and diameter through both the valves, each about 4 lines.

About thrice the size of a minute Cotteswold Inferior Oolite species which possesses
a similar figure, but whose costae are irregular. Astarte Bulla, Goldf., is also globose, but
has only half the number of costae. A. inlegra, Goldf., has less convexity and is more
oblique ; other small species, figm-ed by Roemer, Buvignier, and by Quenstedt, have less
convexity and more obliquity.

Geological Position and Localifi/. One of the more rare testacea of the Scarborough
Coi'nbrash; in the collection of Mr. Leckenby.

Astarte Pontonis, Lgc. Tab. XL, fig. 31.

Testa parva, convexa, ovato-orhiculari, umboriihus suhmedianis, acunwiafis, antrorsum
curvatis, uiargine cardinali elongato, siibrecto, oblique dedivi, lunula magna, costata ; valvis
costis concentricis numerosis (20) elevatis, rotundis, inierstiis angustis ; latere superiore,
area, elongata, planata et Itevigcda.

Shell small, convex, ovately orbicular ; umbones elevated, pointed, nearly mesial, and
curved forwards ; hinge-border lengthened, nearly straight, sloping obliquely downwards,
forming a narrow, smooth area, separated from the costated part of the shell by an acute
angle ; the lunule is large, costated, and somewhat excavated ; the surfaces of the valves
have large, numerous (about 20) concentric, elevated, and rounded costae, separated
by more narrow interstitial spaces ; adult shells have a large fold of growth near to the
lower border.

A small, convex, neatly ornamented species, allied to A. minima, Phil., and A. pisum,
Kock and Dunker ; from the former it is distinguished by the more numerous and more
closely arranged costae, by the more pointed and more curved umbones, by the larger
lunule, and by the posterior, straight, smooth, acutely bordered area; the latter feature will
also separate it from A. pisum and from A. supracorallina, D'Orb.

The height and lateral diameter are about 4 lines.

Geological Position and Localities. It is abundant in the White Oolite (Great
Oolite ?} of Ponton, Lincolnshire.

76 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

AsTARTE Bathonica, Lyc. Tab. XL, figs. 23, 23 «.

Testa ovato-trigona, crassa pbbosa ; nmbonibus sub-anticis antroswn curvatis ; lunula
cordafa, excavata, marginibus rofundatis, latere postico obtusangulo formante, superjicie costis
regularibus, rotundis, crebris, concentricis, marginibus interne denticulatis.

Shell ovately trigonal, thick, gibbose ; umbones anterior and curved forwards ; lunule
excavated, cordate, its margins rounded ; the posterior side has an obtuse, oblique angle ; the
surface has closely arranged, rounded, regular, concentric costae ; the margins of the valves
are denticulated internally.

Height, fi lines ; opposite diameter, 5 lines ; diameter through the valves, 4^ lines.

A short and very convex, thick, shell, with elevated umbones and slightly truncated
posterior border, which is pointed at its inferior extremity, near to which is a large fold of
growth.

Geological Position and Locality. Hampton, Cliffs near Bath ; collected by W,
Walton, Esq., -who states that, having found it at the base of the cliffs, some doubt may
exist as to its real geological position. The mineral character of the specimen is ferru-
ginous and identical with that of the bed of Great Oolite Corals and of other shells which
unquestionably belong to the Great Oolite.

AsTARTE MSTiCA, Walton, MSS. Tab. XXXV, fig. 5 ; Tab. XL, f. figs. 8, 8 a.

Testa parva, crassa, ovafo-obloiiga, plano-convexa, umbonibus parvis, antemedianis,
acutis, margine, cardinali brevi, subliorizontali, antice rotundato, basi snbarcuato, marginibus
internis dentatis ; latcribus costis angustis imprimis rcgidaribiis, deinde incequaJibus.

Shell small, ovately oblong, moderately convex, with thickened margins, internaly den-
ticulated ; umbones anterior to the middle of the valves, curved forwards, and acute ; hinge-
border short and horizontal, terminating in an obtuse angle. The anterior border is
rounded ; the lunule is only slightly excavated ; the base line is nearly straight ; the sur-
face of the valves has an obscure, posterior, oblique angle ; the costae are narrow, at first
regular, afterwards they become irregular and crowded.

Length, 5 lines ; height, 4 lines ; diameter through the valves, 3 lines.

Much variability exists in the prominence and arrangement of the costae, which are
sometimes very numerous and nearly obsolete, or they are distant and elevated. A little
species, allied to ^. Volfzii, B.oem., J. recondita, 'Phil., and the young of ^. rhomboidalis,
Phil. ; neither of these species, however, has the test so thickened towards the margins.

Geological Position and Locality. The Forest i\Larble of Laycock, Somerset ; in the
cabinet of W. Walton, Esq.

BIVALVIA. 77

AsTARTE FiMBRiATA, /Fa/Zo;?, MSS. Tab. XL, figs. 3 4, 34 «.

Testa transversa, ovata, suhdepressa, umbotiifjus anieniedianis parvis, viarg'me cardi-
nali elongato, sutjrecfo, olAiquo, acido ; lunula ma(/na elliptica ; lateribus costulis concen-
tricis acutis, elevatis subdistatitibus ; cetate j^rogrediente crebrioribus et irrcgularibus
instructis.

Shell transverse, ovate, somewhat depressed ; umbones small, depressed, curved forwards;
hinge-margin lengthened, nearly straight, its margin acute and rendered fimbriated by
the acute, projecting extremities of the costce, which are elevated, concentric, distantly
arranged, and regular in the young shell, but more closely arranged and irregular in
specimens of adult growth ; the lunule is large, elliptical, its margins acute.

Allied to J. depressa, Goldf., compared with which the umbones are less prominent
and more oblique, the hinge-border more lengthened, the costse more elevated and fewer ;
the convexity of the valves is also greater. The test is thinner than is usual with this
genus.

Occasionally a small and ill-preserved specimen has been found in the Great Oolite of
Minchinhampton, and mistaken for A. minima, Phil. ; the costse in the latter shell are more
obtuse and more closely arranged, the general figure being more orbicular.

Geohfjical Positions and Localities. The Forest Marble of Farleigh and the Great
Oolite of Bussage, near Bisley Common.

ASTARTE? IGNOTA, Li/c. Tab. XL, fig. 10.

Test a subovata, subdepressa, postice truncata, inferne etpostice oblique subangulata, uni-
bonibus antemedianis acuminatis, lunula parva, superjicie, plicis incrementi numerosis, deli-
cate instructis.

Shell subovate, subdepressed posteriorly, with a truncated extremity to the
hinge-border and with an oblique angle proceeding from the umbo to the inferior-
posterior border ; mnbones antero-mesial, pointed, and curved forwards ; lunule slightly
impressed ; the surfaces of the valves with delicate, irregular, numerous phcations of
growth.

The hinge not having been seen, the genus is rather doubtful ; possibly it may be a
Ci/pricardia.

Geologiccd Position and Localifij. The Forest Marble of Laycock ; in the collection of
W. Walton, Esq.

78 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

ASTARTE HiLPERTENSIS, Lijc. Tab. XXXVI, fig. 10.

Testa crcissa, convexa, ovato-trigonata, umbonibus subanfieis prominentibus, lunula ovafa
profunda, margine cardinali curvato, elongato, oblique declivi, marginibus anterioribus, pos-
ierioribus et inferioribus ellipticis curvatis ; superfieie plicis incremenfi crebris tenuibus.

Shell thick, convex, ovately trigonal ; umbones antero-mesial, elevated, and curved
forwards; lunule smooth, ovate, deep ; hinge-margin lengthened, cnrved, sloping obliquely
downwards ; the anterior, posterior, and lower borders curved elliptically ; the surface with
delicate, numerous plications of growth.

A large, thick species, somewhat allied to A. mbtrigona, Munst., but more convex, less
angulated, and with a larger lunule.

Geological Position and Localitg. The Corubrash of Hilperton, Wilts, in the collection
of W. Walton, Esq.

AsTARTE Aytonensis, Bean MSB. Tab. XL, fig. 13.

Testa ovato-otdonga, valde elongata, compressa, umbonibus depressis anfemedianis,
lunula concava, margine cardinali subhorizontali elongata, margine inferiore parallel o ; late-
ribus rugis ellipticis, crebris, depressis suhregularibus instructis.

Shell ovately oblong, much elongated, compressed ; umbones anterior to the middle of
the valves flattened ; lunule concave ; the hinge-margin lengthened and nearly horizontal ;
lower border conformable ; the two extremities elliptically rounded ; the surface with closely
arranged, depressed, rounded, elliptical, partially irregular rugse.

The general aspect has some resemblance to the shell figured in Part II, PI. IX, figs.
18, 19, as a variety of Astarte excavata, but still more flattened and more elongated, with
more conspicuous, regular, elliptical rugae. Additional experience now leads me to rank A.
excavata, var. compressiuscula, as a distinct species, and not as a dwarfed variety of the large
Inferior Oolite shell ; the present form is even more thin and flattened than compressiuscula,
so much so as scarcely to allow any space for the animal.

Length nearly twice the height ; the diameter through the united valves is little more
than equivalent to their apparent thickness.

Geological Positions and Localities. The Great Oolite of Hampton Cliffs and of
Comb Down, near Bath ; collected by W. Walton, Esq. It occurs also in the Calcareous
Grit of Ay ton, near Scarborough, quite unaltered in any particular ; the name from the
locality having been adopted by Mr, Bean many years since, and sent to public collections,
has therefore been retained.

BIVALVIA.

ASTARTE FLEXICOSTATA, LlJC. Tab, XL, fig. 26.

Testa transversa, subtriffona, convexa, umbonibus anticis acutis, elevatis, marline an-
teriore truncata, abrupte declivi in/erne angula formante ; lunula magna leevigata concava,
margine acuta ; margine inferiore subredo ; margine posteriore imprimis subhorizontall
postice oblique declivi ; superfcie striis concentricis regularibus instructis, in medio evanes-
centibus.

Shell transverse, subtrigonal, convex ; umbones anterior, pointed, and conspicuous ;
anterior side truncated, descending abruptly, and forming an angle with the lower border
at its extremity ; the lunule is large, concave, smooth, with an acute margin ; the lower
border is nearly straight ; the posterior margin is nearly horizontal for the half of its length,
then slopes obliquely downwards ; the shell is moderately convex, with an oblique, obtuse
angle, posterior to which the surface is more flattened ; it has regular striations, which
follow the direction of the lines of growth ; they are conspicuous near to the umbones,
but disappear upon the middle portion of the dorsal surface.

Height, 5 lines ; length, 7 lines ; diameter tlirough the united valves, 3^ lines.

Geological Position and Locality. Collected by E. Witchell, Esq., in the white stone
(Great Oolite) of Bussage, near to Bisley Common; a single specimen.

Gresslya pereguina, Fkih, sp. Tab. XXXVI, figs. 2, 2 a, b.

In addition to the specimen figured in PL XV, Part II of the ' Great Oolite Monograpli,'
it has been deemed advisable to exemplify three other variations of form, Iiy the aid of
which the intermediate connecting links may readily be imagined. This Gresslya is very
abundant in the Cornbrash, both in Wiltshire and Yorkshire, so that ample opportunities
are afforded of studying every variation of form which it presents ; these, as will be seen
from our figures, are so considerable and so common tliat it seems impossible fairly to
disconnect from them some other examples of Gresslya from the Inferior Oohte, as TJnio
ahductus, Phil., Gresslya latior, Ag., G. conformis, kg., G. lunulata, kg., G. erycina, Ag.,
G. concentrica, Ag., and perhaps also G. zonata, Ag. In all these the same kind of
surface obtains, and the outer, granulated tegument is precisely identical, belonging to
that section of the genus in which the radiating lines and the granules are of the most
minute size, and very densely arranged. It has been usual to select for G. abducta
Inferior Oolite examples with short forms, elevated umbones, tumid anterior sides, and
compressed posterior sides ; but the shortness of figure is surpassed by some from the
Cornbrash, and the inflation of the anterior side varies in amount with every specimen.
From these, probably, must be separated G. latiroslris, Ag., which attains to large

80 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

dimensions, with a lengthened general form, compressed anterior side, and large longitudinal
plications over the whole of the surface ; it appears to be comparatively rare, and belongs
to the upper stage of the Liferior Oolite.

Thracia amygdaloidea, Lfjc. Tab. XLIII, fig. 4.

Testa convexa, elongata, umhonibus depressis submedianis, latere antico producto, ro-
tandato ; postico subcompresso, attenuate, basi curvato, plicis longitudinalibus paucis,
leviter instrudis.

Shell elongated, convex ; umbones postero-mesial, depressed ; anterior side produced,
its margin curved elliptically ; posterior side rather compressed and attenuated, its superior
border slightly excavated ; the base is nearly straight ; the surface has a few faintly
marked, longitudinal plications of growth.

Compared with other examples of the genus, the length and the convexity are con-
siderable ; the umbones are likewise much depressed, obtuse, and but little conspicuous ;
the posterior angle is only distinguishable near to the umbones ; the posterior extremity is
slightly truncated. The height only very slight exceeds half the length.

Geological Fosition and Localitij. Associated with valves of Mi/aciles calcei/oriiiis in
flaggy, argillaceous Oolite, upon the western border of Minchinhampton Common, at the
lower boundary line of the Great Oolite ; a single specimen.

IMyacites calceiformis, Phil., sp. Part H, Tab. XI, fig. 2 ; et Tab. XLII, figs. 1,1a.

As this shell possesses considerable variability of figure, another example is given from
the Cornbrash of the Yorkshire Coast. In the former description (p. 114, line 8), these
words should be erased — " in the upper beds of the Inferior Oolite." An examination of
numerous Yorkshire specimens has proved that they were all obtained in the Cornbrash,
including the original specimen figured in the ' Geology of Yorkshire,' which was erroneously
placed with the Inferior Oolite fossils, and fig\u'ed with them in pi. xi of that work.
The Cornbrasli specimens have the test with its granulated tegument well preserved, but
usually the fossil has undergone some compression or distortion. The former figure,
Plate XI, fig. 2, represented a ]\Iinchinhampton specimen from the base of the Great
Oolite. An Inferior Oolite shell frequently mistaken for Mgacites calceiformis occurs
only in the form of casts ; it is more gibbose, with larger, more elevated umbones, the
posterior side being much shorter and more attenuated. As the casts are common, and
these distinctive characters are persistent, there can be no doubt that it must be dis-
tinguished from the species of Professor Phillips. Authorities generally have followed the
' Geology of Yorkshire,' and placed Myacites calceiformis in the Inferior Oolite, and Dr.

BIVALVIA. 81

Oppel (' Juraformation') has made the Cornbrash shell into a new species, with the name of
Panopea Haueri ; I can, however, with confidence state that there is no evidence that the
fossil in question has ever been obtained in Yorkshire lower than the Cornbrash ; in
Gloucestershire its lowest position is at the base of the Great Oolite.

Myacites recurvum, PJtil., sp. Tab. XXXVI, figs. 4, 4 a.

Amphidesma kecurvtjm, Phil. Geol. York., i, pi. 5, fig. 25.
LuTRARiA siNUOSA, Roemer. Ool., tab. 19, fig. 24, Nachtr., p. 42.
Pleuromya recurva, Jff. Et. Cret. Myes., p. 234 et p. 246, t. 29, fig. 9.
Lyonsia recurva, B'Orb.l Prodr., 12 et.. No. 123.
Myacitess recurva, Mor. Cat. Brit. Foss., 1854, p. 214.
Amphidesma recurvum. Bean. Mag. of Nat. Hist., 1839.
Myacites recurvum, Lechenhy. Proc. Geol. Soo., vol. xv.

Teda ehngato-trcqjeziformi plano-convexa concentrice striato-nigosa antice brevissima
oblique tnmcafa basi ■perarcuata posterius prodncfa dorso antice sinuatim depressa, maryine
cardinali posfico sinuato, umhonihus crassis incurvis. (Roemer.)

Shell a lengthened trapeziform, moderately convex, Avith large, concentric, rugose pli-
cations ; anterior side very short, obliquely truncated ; base curved elliptically ; the posterior
side produced, compressed, close-fitting ; the superior margin somewhat sinuated or
concave ; the unibones elevated, pointed, and incurved. Usually the anterior side has a
furrow, which passes from the umbones downwards perpendicularly or slightly directed
forwards to the inferior border, but in some of the more gibbose specimens it cannot be
distinguished. The test is delicate; the ornamentation of the surface has the radiating
hnes of granules so dense and minute, that they can only be distinguished by the aid of a
considerable magnifying power. The heiglit is two thirds of the length, the diameter
through the valves being equal to half the length. These dimensions apply to the shorter
Cornbrash examples, but many of the Kelloway Rock specimens are more elongated. To
the latter variety may be attributed the Lutrarla sinuosa, Roemer ; it is necessary, however,
to separate altogether the Lutraria recurva, Goldf. ('Petref.,' tab. cliii, fig. 15), which has
the general figure very different. The example of Agassiz is unusually short and gibbose ;
and as he has figured a cast, we are precluded from comparing the ornamentation of the
surface. D'Orbigny ('Prodrome,' i, p. 359) has separated it under the title of Panopea
subrecurva ; but, considering the varieties of figure which this species assumes, probably it
is only a short variety of the species of Professor Phillips.

Myacites recurvum possesses so little of the aspect of a Gresslya (Lyonsia, D'Orb.)
that we are led to speculate upon the probability that Lyonsia recurva, D'Orbigny, is a
form erroneously ascribed by that author to the species in question.

Geological Positions and Localities. Myacites recurvum is almost peculiar to the

11

82 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Oxfordian Oolites ; for although it occurs in the Cornbrash of Yorkshire and Wiltshire, it
is rarely found in a lower position than the Kelloway Rock. Roemer records his Lutraria
sinuosa in the Lower Coral Rag of Heersthum ; Agassiz places his Pleuromya recurva in
the Terrain a Chailles of Chamsol, in the department of Doubs.

Myacites sinistra, Agassiz, sp. Tab. XXXV, figs. 17, 17 a.

Arcomya sinistra, Agassiz. £t. Crit. Myes., p. 170, tab. 9, figs. 1 — 3, et tab. 9',

figs. 10—13.
Panop^a sinistra, If Orb. Prodr., i, p. 273.
— — Oppel. Juraformation, p. 480.

Testa ovato-ehngata antice attenuata, postice convexa jjroducta, margine Manfe,
umbonibus subcompressis, depressis, antemedianis, latere antico oblique-dedivi, lunula
concavo, margine superiori subhorizontali margine inferiore subrecto ; valvis laieribiis
plicis irregularibus crebis longitudinalibus, et sulco superficiali antemediano oblique-declivi.
Nucleus glabcr.

Shell ovately elongated, with the sides of the valves rather flattened ; anterior side
attenuated, its margin sloping obliquely downwards ; lunule concave ; posterior side more
convex and lengthened, its superior border nearly horizontal ; the posterior extremity is
somewhat rounded, with an aperture moderately large ; the umbones are depressed, and
somewhat compressed laterally ; they are placed a little posterior to the anterior third of
the shell, and there is a slight sulcation, which proceeds from them obliquely forwards and
downwards towards the lower border; the inferior margin is lengthened and nearly
straight; the surface of the test has numerous irregular and rather delicate longitudinal
plications ; the granules over the greater portion of the valves are so minute and crowded
that they cannot be traced to form connecting lines, but towards the sides they are larger,
more distantly arranged, and distinctly linear ; the test upon the anterior side is of
moderate thickness, posteriorly it is much thinner; the nucleus is smooth, and exhibits
the adductor and pallial scars.

Length, 2 inches ; height, 1 inch ; diameter through both the valves, | inch ; but our
specimen is imperfect, and appears to have lost about 2 lines in length at the posterior
extremity.

The more depressed umbones, the anterior attenuation, and the nearly horizontal
figure of the superior border, will serve to distinguish it from all the varieties of Plcuromga
eiongata, Ag., to which it bears some resemblance.

The Arcomya sinistra of Quenstedt, ' Der Jura,' p. 451, tab. Ixii, fig. 2, from the higher
stage of the Inferior Oolite, occurs also in the same position iu the vicinity of Cheltenham ;
it is, however, distinct from Myacites sinistra. Some varieties of Myacites decurtatum
approach to it in the general figure, but are readily distinguishable when the granulated

BIVALVIA. 83

surface can be examined and compared, the minute, crowded pattern upon M. sinistra,
with the widely separated lines of granules upon M. decurtatum.

Geological Positions and Localities. The Cornbrash of Scarborough ; in the col-
lection of Mr. Leckenby. In Switzerland M. Agassiz records it from the same geological
position (calcaire roux-sableux) at Goldenthal, Soleure ; also in the Bernese Jura.

Mtacites modica. Bean, sp. Tab. XLIII, figs. 1, \ a.

Mya modica, Bean. Mag. Nat. Hist., 1839.

Testa-ovato elongata suldepressa, vmbonibus sitbdepressis antemedianis, marline antico
producto, rotundo, postico oblique declivi suhrccto, margine inferiore elliptico curvato, area
ligamenti lanceolata lata, subdepressa, marginibiis acutis, valvis lateribiis concentrice delicate
plicatis ; lineis radiantibus granulatis, siibtillissimis dense instructis.

Shell ovately elongated, rather depressed ; umbones antero-mesial, rather depressed ;
anterior margin produced, rounded; posterior margin more lengthened, nearly straight,
sloping downwards obliquely, lower border curved elliptically ; the granulated test consists
of extremely delicate, very densely arranged, radiating lines, visible only under a magnifier;
the concentric plications are numerous and faintly traced, so that the surface is smooth ;
the valves are close-fitting, or have no perceptible aperture at either of the extremities.

Length, 2^ inches; height, 1^ inch; diameter through both the valves, \ inch.

The general figure and aspect of this species renders it easy to distinguish from other
examples of the genus.

Geological Position and Locality. The Cornbrash of Gristhorpe Cliffs, in which it has
occurred very rarely ; Mr. Leckenby 's collection.

Anatina (Cereomya) siliqua, Ag. Tab. XXXV, fig. 15.

Sanguinolaria undulata, Thil. Geol. York., i, pi. 5, fig. 1, non Sow.
Ceecomya siliqua, Ag. Et. Crit. Myes., p. 148, tab. II a, figs. 9 — 13.

— AKTICA, ^y. ? lb., p. 147, tab. 11, figs. 16—18; tab. Ila,

figs. 14—16.
Anatina Bellona, jyOrb. Prod., i, p. 336, 12 et., No. 132.

— tNDATA, Id. lb., p. 3C1, 13 et., No. 221.
Sangdinolakia undulata, Quenstedt. Der Jura, p. 508, t. 68, fig. 9.
Anatina undulata, Leckenby. Proc. Geol. Soc, vol. xv, 1858.

Testa transverse elongata incequilatera umbonibus subanticis j^arvis acutis, postice

84 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

rostraia, attemiata, area lata, plicis duobus lonr/itudinalibus ; latere antico suhcompresso,
elliptico curvato, plicisque reguJarihus et lonc/itudinalihus.

Shell transversely elongated, very inaequilateral ; umbones placed anterior to the
middle of the valves, small, depressed, and anterior; posterior side rostrated or attenuated,
and much elongated ; area large and wide, with two longitudinal ridges, in addition to a
distinct marginal ridge which separates the area from the other portion of the shell ;
anterior side rather compressed, its border is curved elliptically ; the anterior portion of
the sides of the valves have regular, longitudinal ridges and furrows, which disappear
posterior to the umbones ; the oblique sulcation which proceeds downwards from the
umbones in all examples of Cercomya is only faintly impressed.

The specimen figured has the general form of the shell unusually well preserved, but
the test has disappeared ; the very inequilateral figure, with the attenuation and elongation
of the posterior side, will readily distinguish it from Anatina undulata^ Sow., as also from
most other examples of the genus.

Height, one third the length; diameter through both the valves, one fourth the
length.

Geological Positions and Localities. It occurs rarely in the Cornbrash of Scarboi'ough.
Professor Philhps has recorded it in the Oxford Clay, and Mr. Leckenby in the
Kelloway Rock and Calcareous Grit of Yorkshire. M. Quenstedt quotes it from the
Cornbrash of Wurtemburg ; M. Agassiz from the Oxfordiaa Strata of the Vadois Jura and
the Jura of Soleure.

Pholadomya ovulum, Ag. Tab. XXXV, figs. 18, IS a.

Pholauomya ovuLCSf, Ag. Et. Crit. Myes., p. 119, tab. 3, figs. 7 — 9; tab. 3 6,

figs. 1 — 6.

— — B'Orb. Prodr., 11 et., No. 168, vol. 1.

— — Morris. Catal. Brit. Foss., 1854, p. 221.

— — Oppel. JuraformatioD, p. 481.

Testa ovato-elongata, antice breviore, rotundata, cor data, posterius prodncta, attenuata,
margine inferiore arcuato curvato, superiore subhorizontali, concavo, umbonibis crassis
subanticis prominulis ; valvis concentrice plicatis, plicis longitudinalibus numerosis ince-
qualibus mediocriter tenuibus ; cosfellis radiant ibtis obliquis cequalibus angustis, inferne
evanescentibus, apertura postico et antico angusto.

Shell ovately elongated; the anterior side short, rounded, cordiform ; the posterior side
produced and attenuated ; the inferior margin is curved elliptically ; the superior margin is
moderately lengthened and concave ; the umbones are elevated and tumid ; the sides of
the valves are convex, with closely arranged but not prominent longitudinal plications ;
the radiating costas are very narrow or linear, disposed obliquely, about twelve in number;

BIVALVIA. 85

they are slightly impressed by the decussating plications, and disappear before reaching
the lower border ; the apertures, both posterior and antero-inferior, are narrow, and not
much lengthened ; the post-ligaraental area is wide, and bounded by a distinct elevation
upon each side.

The test is thin, and is sometimes preserved, the characters of the surface being very
well shown upon the casts ; in many specimens the radiating lines, or little costte, are so
faintly marked that they are only visible near to the umbones. The very delicate,
radiating little ribs and the nearly equally faintly marked longitudinal plications will
usually serve to distinguish it from allied forms of the genus when combined with the
elongated figure. In the Pholodomyge the relative measurements of the parts are little to
be depended upon ; but in the Cornbrash specimen figured, the diameter, the height,
and the length, are as 1 — 1^ — 2. Occasionally the length has a greater proportion.

Geological Positions and Localities. It is somewhat rare in the Cornbrash of the
coast of Yorkshire, but it is common in the Inferior Oolite of the Cotteswold Hills, its
position being the stratum with Conchifera immediately underlying the bed with
Gryphcea sublobata.

Pholadomya Phillipsii, Pliil, sp. Tab. XLII, figs. 2, 2 a.

Pholadomya Murchisoni, Phil. Geol. York., i. pi. 7, fig. 9, nou Sow.
— Phillipsii, Morris. Cat. Brit. Foss., p. 221

Testa ovato-cordata, injlatra, umhonibus inagnis elevatis, antice brevissima truncata,
postice producta, vahle Jiiante ; lateribus rugis irregularibus ntimerosis, leviter impressis,
costisque (7 — 8) perpendiculariter , angustis ; costa secunda majora.

Shell ovately cordate, much inflated ; umbones large, anterior, elevated, but obtuse ;
anterior side short and truncated ; posterior side produced, its superior border concave,
with a lengthened, large aperture, which extends upwards even to the ligament ; the sides
of the valves have very numerous, irregular, longitudinal rugae, which are not very promi-
nent, and only slightly indent the narrow, perpendicular costse, of which there are seven or
eight ; the second costa is much larger than the others, and is more remotely placed,
imparting a degree of angularity to the anterior side of the shell ; the other costse are
symmetrica], and descend almost perpendicularly to the lower border, leaving a con-
siderable space upon the posterior side of the valves destitute of costse. The young shell
is much less inflated, and more produced upon the posterior side, the aperture at that part
being, in proportion, more narrow ; the second costa has very little more prominence than
the others, so that the anterior side has less angularity and its border is more rounded
than in the adult form. In old specimens the height and convexity of the valves are
nearly equal, the length being a little more considerable ; in young shells, not exceeding an
inch and a half in length, the convexity is one third less.

86 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

It has only been after long consideration, and an ample comparison of specimens of
various dimensions, that I have seen fit to adopt the view taken by Professor Morris in his
' Catalogue,' and separate this shell both from Pholadomya deltoidea and from Pholadomya
Heratdti, of the Inferior Oolite. Compared with the latter form, it will be found that
P. PMUijjsii has the anterior side more truncated, and the posterior side gapes with a
larger aperture ; this latter feature is, in fact, distinguishable in shells of all dimensions ;
the longitudinal rugse are more irregular and much less conspicuous, so that they only
slightly indent the costse, these latter being less oblique than in P. HerauUi. The
superior largeness and regularity of the rugge, together with the deep indentations of the
costse, is the feature which, at the first glance, impresses the spectator upon inspecting
P. Heraulti ; the costse are usually somewhat more numerous, there being two anterior
to the large costae and an additional one posterior to it, so that, together with their
greater obliquity, only a small portion of the posterior side of the shell is destitute
of costae.

Compared M'ith P. deltoidea, Sow., the figure of the latter is more inflated, the costae
larger and less indented, it also is without the angularity which is imparted by the second
large costa of P. PMllijjsii.

Geoloc/ical Position and Localiti/. Pholadomya PJtillijmi is abundant in the Cornbrash
of Scarborough, Gristhorpe, &c., and usually has the test preserved.

Pholadomta deltoidea, Sou\ Tab. XLII, figs. 4, 4 a.

Caedita deltoidea, Sow. Min. Con., t. 197, fig. 4.

Pholadomya Muechisoni, Sow. lb., t. 545, the shorter figure only.

— BUCARDIUM, Ag. £t. Crit. Myes., p. 77, pi. 5, figs. 3 — 7 ; pi. 5 a,

fig. 8.

— — Chapuis and Deivalque. Fos. Ter. Sec. de Lu.tembourg,

p. 124, pi. 18, fig. 1.

— — Damon. Geol. Weymouth, p. 17, fig. 6.

— SOLITARIA, Mor. and Lije. Gr. Ool. Moll., part 2, p. 124, tab. xii, fig. 2,

ettab. 11, fig. 1.

This species, so abundant in the Great Oolite, Fuller's Earth, and Cornbrash of the
south of England, varies greatly in its general figure, even in the same bed and locality ;
and as its synonyms may now be considered as clearly ascertained, I have deemed it
desirable to figure a specimen from the Cornbrash of Wiltshire, in which the costae are
irregularly arranged, and the general figure is more lengthened than in the two specimens
formerly figured in the second part of the ' Monograph of the Great Oolite Mollusca,*
under the name of P. solitaria. Of these latter, the index facing Tab. XII, fig. 2, by a
typographical error, was printed P. otjlita, a shell which is given at fig. 5 upon the same
plate. Even the two Great Oolite specimens have the anterior side less truncated, the

BIVALVIA. 87

umbones more obtuse, and the general figure less inflated, than obtains in the greater
number of those from the Minchinhampton district ; and, upon the other hand, all of them
are less lengthened upon the posterior side than is seen in the figures given by Agassiz
and by Messrs. Chapuis and Dewalque.

Pholadomya deUoidea is remarkable for the large, prominent, and slightly indented
costse, usually seven in number, of which tlie two posterior ones are much less conspicuous,
and are usually evanescent towards the lower border.

The frequent truncation of the anterior side in Pholadomya, and the general distortion
of the shell which usually accompanies it, is a source of frequent difficulty in the dis-
crimination of species, and is seen commonly and even usually in P. delfoidea, when
specimens are collected without selection. The shell in its normal position rested upon
the compressed anterior side ; the general distortion of figure consequent upon it com-
menced at a very early period in the growth of the mollusc, continued throughout its
existence, and did not prevent it from attaining to the usual dimensions of the species ; it
occurs equally in all the other forms assumed by the genus. Where the flattening of the
anterior side is considerable the umbones become more pointed and prominent, the
radiating elevations or ribs are directed more obliquely backwards ; in other instances they
become more closely arranged, or they are waved and irregular. The distortion is not
limited to specimens connected with any particular kind of lithological condition, as it
occurs in compact, thin-bedded limestones, in thick beds of soft, sandy marl, or in thick-
bedded Oolitic hmestone; it is also common to find both compressed and uncompressed
examples in contiguity.

Pholadomya lyuata. Sow. Tab. XLIII, figs. 3, 8 a.

Cakdita? lirata, Sow. Min. Con., t. 197, fig- 3.
Pholadomya lykata, Soiv. Ibid., p. 220.

— — Oppel. Juraformation, p. 482.

Tesia ohovato-irigona, ventricosa, umbonibus elevatis antero-medianis, latere antico
truncato, jwstico oblique decllvi, costis 9 — 10, tertia majora, carinam effomaiite, costis
aliis approximatis, plicis magnis concentricis regularibus indentaiis ; apertwra postica
angmta, elongata.

The figure is nearly that of a cone, compressed laterally ; the umbones are elevated,
pointed, and placed a little anterior to tlie middle of the valves; the steepness and
straightness of the posterior slope, together with the nearly straight lower border, imparts
a distinctive character to the shell, irrespective of the large, carinated third costa, which is
so much more conspicuous than the others that it forms a kind of keel or angle upon the
anterior side; it descends to the lower border without curvature, but is directed slightly

88 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

forwards ; the six or seven costje posterior to it are much smaller, they diminish
regularly in prominence, are closely arranged, and are deeply indented by the regular,
large, concentric plications ; the anterior side gapes slightly, and has two inconspicuous,
indented costse ; the posterior aperture is narrow and lengthened.

The sub-conical figure, pointed posterior side, and large, carinated rib, will serve to
distinguish it from P. Heraulti, Ag., to which it is nearly alhed ; the more angulated
figure, and more numerous costge, from P. carinata, Ag. Some examples of Pholadomya
from the Inferior Oolite are not distinguishable from P. lyraia ; but between these and
P. Heraulti are others, which apparently serve to connect the two forms, so that it is
difficult to separate them altogether from P. Jyrata, although undoubtedly they must be
merged with P. Heraulti ; these connecting links are also quite irrespective of any changes
that may be due to the stage of growth in either of the two species.

Geolo(jical Positions and Localities. P. li/rata is common in the Cornbrash of
Wiltshire and Dorsetshire. Dr. Oppel records it in the same rock at Marquise, near
Boulogne, and Egg, near Aran. D'Orbigny (' Prodrome,' i, p. 252) quotes it from the
Upper Lias, near Bath, which is an error copied from the ' Mineral Conchology of
Great Britain.'

HoMOMYA GiBBOSA, Sow., sp. Part II, Tab. XII. fig. 14; Tab. XLIII, figs. 2, 2 a.

Described at page 138, Part II, under the name of Myacites gihhosus. As this shell
occurs abundantly both in the Cornbrash and the Inferior Oolite of the southern counties
of England, a full-sized average example is here figured ; occasionally, indeed, the species
acquired much larger dimensions, as in the Cornbrash of Wiltshire, but it is then
invariably more or less distorted and imperfect ; it is also more gibbose than the smaller
examples. Since the publication of the former portions of this Monograph more
extended information respecting this and other allied species comprised in the proposed
genus Homomya of Agassiz has led to the conclusion that they cannot be assigned to the
genus Myacites, of which they possess neither the external granulated tegument nor the
peculiar characters of the hinge.

When the surface of Myacites has been denuded of the granulated tegument it is
smooth, with irregular, longitudinal laminae, whereas Pholadomya and Homomya have a
wrinkled or corrugated surface.

The genus Homomya was intended by Agassiz to include shells whose forms
resemble those of the more lengthened Pholadomyas, but which are destitute of radiating
costse, and have usually a thicker test, the hinge being identical with that of Pholadomya,
usually, indeed, more massive ; but although the sides of the valves are destitute of
costae, it occasionally happens that a few delicate, radiating lines, more or less obscurely
marked, are visible upon the umbones, but vanish before they reach the middle of the

BIVALVIA. 89

valves. Examples of this are supplied by the large Liassic Homomya vcntricosa, kg.,
by Homomya Vezelayi, D'Arch., and by Homomya crassiuscula, Mor. and Lye. The
hinge of the latter shell exhibits its perfect identity with that of Pholadomya. It is
therefore evident that Homomya cannot claim a generic separation ; but that, viewed as a
subgenus or section of Pholadomya, the name may conveniently be retained. Myacites
Vezelayi, page 111, and Myacites crassiusculus, page 112, should therefore also be removed
to Homomya.

Homomya crassiuscula, Mor. and Lye. Tab. XLIII, figs. 5, 5 a.

A small example from the Great (?) Oolite of Lincolnshire was figured, Part II,
Tab. XI, fig. 3. As the species occurs of full dimensions in the Cornbrash of Scarborough,
a specimen, with the test preserved, is here given.

i2

ADDENDA.

A PORTION of the text of this Supplement passed through the hands of the'printer long
prior to the execution of the plates; and during this lengthened interval many additional
testacea were placed at the disposal of the author, including a considerable series from the
Forest Marble of the counties of Wilts, Somerset, and Dorset, which had recently been
disengaged from the investing matrix by the exertions of W.Walton, Esq., of Bath,
obtained by that gentleman, and by the late John Kilvert, Esq., of the same place. This
fine collection has yielded many new forms, and also some superior examples of others
that had previously been figured from specimens less suitable for the purpose ; advantage
has been taken of the opportunity thus afforded to give additional illustrations. The
descriptions of the more recently acquired fossils could not, therefore, for the most part, be
placed in their proper order, and necessarily form Addenda to the Supplement.

Cerithium (?) HEMiciNCTUM, Lyc. Tab. XLI, fig. 17.

Tesia parva, elongata, anfractibus (7), valde conveoois, postice subplanis, Imvigatis,
antice tricinctis, convexis, anfracfu ultimo basi concentrice sfriafo. Apertura et canali
ignota.

Shell small, elongated ; volutions (7) very convex, their posterior portions oblique,
flattened and smooth, their anterior portions with three prominent encircling costaj, the
sutures are deeply constricted ; the last volution has the base concentrically sulcated ; the
outer lip and the base are imperfect ; the genus, therefore, is somewhat uncertain ; there
are some traces of an umbilical opening at the base of the columella.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

92 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Cerithium (?) NEGLECTUM, Lyc. Tab. XLIV, fig. 2L

Testa parva, subulaba, anfractihm {circa 7) subplanis, longitudinaliter costatis, cosiis (5),
magnis, depressis, suhobliqids, a sinisfro ad dextrum versus, apertura parva, canala (?).

Shell small, subulate ; volutions (about seven) flattened, with five longitudinal large,
depressed, and smooth costae, which are directed somewhat obliquely from left to right,
and are slightly interrupted by the sutures ; the aperture is small and depressed, the canal
is imperfect.

The extremities of the costae do not always exactly accord with those of the next
volution, which gives some irregularity to the appearance of the volutions; no traces of
encircling striations are visible.

The spire is not angulated as in C. pentagonuni , the subulate figure and plain surface
distinguishes it from C. sexcostalum.

Geological Position and Locality. The Great Oolite of Bussage ; collected by
E. Witchell, Esq.

Cerithium costigerum, Piette. Tab. XLI, figs. 11, 11 a, b.

Testa inflata, subcylhidrica, anfractibus {1 — 9), costis (12) rectis, angustis, elevatis,
postice acuminatis, lineisque transversalibus, instructis ; apertura parva, canali recto,
ehngalo.

Shell somewhat inflated and subcylindrical, volutions (7 to 9) with the sides perpen-
dicular, costae (12) perpendicular, narrow, and much elevated, terminating posteriorly each
in a projecting point, anteriorly they bend inwards slightly to the suture, there are also
regular encircling lines ; the base is smooth, the aperture is small, the canal lengthened
and straight.

There is much variability in the elevation of the spire, and, consequently, in the
height of the volutions ; a specimen more than usually lengthened has the costae some-
what oblique.

Geological Positions and Localities. The Porest Marble of Laycock ; in the collection
of W. Walton, Esq. It is recorded by M. Piette in the Great Oolite Limestones of Eparcy
and Rumigny.

Cerithium (?) Waltoni, Lyc. Tab. XLI, fig. IG.

Testa p)arva turriculata anfractihus numerosis angustis, inflatis, saturis bene impressis,
costis rectis angustis, elevatis {circa 11) in ambitu lineis regularibus cingendis ; apertura et
canali ignota.

ADDENDA. 03

Shell small, turreted, volutions numerous (8 — 9), narrow, inflated, the sutures deeply
impressed; costse (about 11 in the circumference) perpendicular and narrow, crossed by
a few regular encircling lines. The aperture and canal are imperfect.

Gpolof/ical Position and Locality/. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

Cerithium (?) pocuLUM, Li/c. Tab. XLIV, fig. 24.

Tesfa parva, sulcylindrica, anfractibus (9) Icemgatis, jjostice expamis et profunda
canaliculatis, antice contractis; apertura parva, canali contracto et contorfo.

Shell small, subulate, subcylindrical, volutions (about 9) smooth, expanded posteriorly
and deeply channelled, contracted anteriorly, the aperture is small, the canal is produced ,
narrow, and twisted.

The genus is somewhat doubtful, additional specimens may prove it to be a Nerincsa.

Geological Position and Locality. The Great Oolite of Bussage, near Bisley Common ;
collected by E. Witchell, Esq.

Cerithium exscalptum, Lye. Tab. XLIV, fig. 23.

Testa parva, suhulo-elongata, anfractibus (10) angustis, siib-planis, transverse tenuissime
striatis, anfractu ultimo rotunda, canali brevi, sub-recto.

Shell small, subulately turreted, pointed, volutions (10) slightly convex, narrow (two
and a half times as wide as high), with numerous very delicate encircling striations, the
last volution has the base rounded, the canal is short and nearly slight.

Obtained by crushing the white stone for the Great Oolite for minute Gasteropoda.

Geological Position and Locality. The Great Oolite of Bussage ; collected by
E. Witchell, Esq.

KiLVERTiA, Gen. Nov.

Testa elongata, sub-cylindrica, anfractibus numerosis, perpendiculariter costatis tubercu-
latis aut spinosis ; anfractu ultimo cylindrico, basi suh-contracto ; apertura integra, rotun-
data aut ovali, labris protractis, tenuiter incrassatis, non tmnquam sub-undulatis, columella
solida.

Shell elongated, sub-cylindrical, sometimes somewhat pupseform ; volutions numerous.

94 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

perpendicularly costated, tuberculated or spiued ; the last volution cylindrical, sometimes
contracted at the base ; aperture entire, orbicular or ovate, the lips elevated, produced
and slightly thickened, sometimes undulated, columella solid.

Allied to Cerithium, Potamides, Turritella, Omphalia, Rissoa, and Aclis ; from the
two former it is separated by the absence of an anterior and posterior canal, the thickened
and produced margins of the aperture distinguish it from Turritella, and from the
Omphalia of ZekeH, from Omphalia more especially by the absence of a sinus or fissure
of the outer hp, from Rissoa by the many-whirled figure and produced lips, from AcUs
by the costated or spined volutions, cylindrical last volution, and produced aperture.

The Great Oolite species obtained in the Minchinhampton district are always small
and sometimes minute, these are Cerithium (?) spiculum, Lye, p. 9; C. (?) drnngulatim
D'Arch., p. 8 ; C. (?) pulclimm. Lye, p. 10, of which latter species very fine and large
examples occur also in the Forest I\Iarble clays of Laycock, accompanied by Kihertia
formosa, Lye. Other examples, known only in foreign localities, are Bissoa (?) elegantula,
Piette, from the Great Oolite of Eparcy ; Cerithium angistoma, C. quinquangulare and
C. pupoides, Hebert and Deslongchamps, from the Kelloway Rock of Montreul-Bellay ;
Scalaria (?) minuta and Cerithium pygmeum , Buvignier, from the Calcaire a Astartes of the
department of the Moselle. In selecting a name for this proposed genus, I have much
pleasure in adopting the suggestion of Mr. Walton, and dedicate it to the memory of the
late John Kilvert, Esq., of Bath, whose researches in the Palaeontology of the Jurassic
rocks of the southern counties resulted in the acquisition of a fine and instructive
collection of the Mollusca.

KiLVERTiA PULCHRA, Lyc. Tab. XLIV, fig, 4 ; Tab. XLI, figs. 12, 12 a.

Cerithium? prLCHRUM, p. 10, of this Supplement.

The fine collection of Forest Marble shells forwarded by the kindness of Mr. Walton,
contains many specimens of this Kilvertia which exhibit much variability in their orna-
mentation, and are upwards of three times the hnear dimensions of the Minchinhampton
examples; the Laycock shells having been obtained by washing layers of clay and shale;
there is an entire absence of that abrasion of the surface to which oolitic fossils have so
frequently been subjected ; additional figures of this fine species will be found Tab. XLI,
figs. 12, 12 ffl. The figure of the aperture in shells of the same size also presents some
variability, the typical suborbicular figure becomes sub-quadrate, and in other instances is
somewhat pointed at the two extremities, but in the young condition apparently the
aperture is always orbicular.

ADDENDA. 95

KiLVERTIA FORMOSA, Lyc. Tab. XLIV, fig. 5.

Testa parva subulo-pupeeformi, anfractibm (6 ?) latis, planafis, suturis bene distindis,
costis longitud'malibus rectis {circa 7 in ambitu) rotimdis, depressis, in/erne evanescentibus ;
lineis transversis {circa 7) regidaribus, elevatis; apertura parva suborbiculari, labris inte-
gris, simplicibus.

Shell small, elongated, pupEeform or lessening at both the extremities, volutions (6?) wide,
flattened or very slightly convex, the sutures well impressed, aperture small, suborbicular ;
the lips continuous without undulation ; longitudinal costa? (about 7) straight, rounded,
and but slightly elevated, indistinct upon the latter volutions, knotted where they are
crossed by encircling lines, of which each volution has about seven, regular and conspicuous ;
the costse are not continuous, neither do their extremities exactly correspond at the sutures
of the successive volutions, they are more prominent upon the upper half of each volution ;
the apex is imperfect, the first volution having disappeared.

Allied to Kilvertia strangulata=Ceritldnm strangidatum, D'Arch., from which it is
distinguished by the smaller dimensions, the greater elongation of the spire, and by the
costa;, which are much smaller, more depressed, and do not form continuous elevations.

Geological Position and Locality. Collected by E. Witchell, Esq., in the white (Great)
Oohte of Bussage, near Bisley Common.

Amberleya capitanea, Gold/., sp. Tab. XLI, fig. 1.

Part I, p. G5, contains a correct description of this species {Turbo capitanews, Goldf.),
which is not uncommon in the Supra-liassic sands and the Inferior Oolite of the southern
counties ; Mr. Walton has also forwarded two small examples obtained in the Forest
Marble of Laycock, and of Pound Pill. The shell figured Tab. IX, Part I, fig. 33, was
referred doubtfully to this species, of which it was supposed to be a badly preserved
example ; subsequent examinations of other specimens from the same locality have proved
that this view was erroneous, and that it is a distinct species ; a description of this latter
shell will be found in this Supplement (p. 19) under the title of Amberleya Jurassi.

Amberleya monilifera, Lyc. Tab. XLI, fig. 10.

Testa parva, ovato-elongata, spira alta, acuta, anfractibus (4 — 5) in medio carinatis,
tabulo-nodiferis, postice et antice concavis, ejusdem carina parva, nodifera ; anfractu
ultimo basi sulcis quinis, conceniricis, apertura antice subcontracto.

Shell small, ovately elongated, spii-e elevated, acute, consisting of four or five volu-

96 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

tions, which have a prominent encirding nodiferous carina in their middle portion, their
posterior and anterior surfaces being concave, each having a small noderous carina ; the
last volution has at its base fine encircling sulcations; the aperture has the anterior
extremity rather pointed.

The tubercles upon the mesial carina are large, projecting slightly forwards, very
closely arranged and tubular, about eighteen in a volution, the anterior and posterior
carinse have similar tubercles, but much smaller. The height of the shell is one third
greater than the opposite measurement.

Geolof/ical Position and LocaUfy. The Forest j\Iarble of Laycock ; in the collection of
W. Walton, Esq.

Amberleya tricincta. Lye. Tab. XLI, fig. 14.

Testa ovafo-elonyata, anfractibus (S — 9) turhinatis, inferne anyulatis, cingillis, iribus
lineis perj)e7idicularibus decussatis, anfractu ultimo, lineis maynis concentricis ; apertura
pyriformi.

Shell ovately elongated, volutions (8 — 9 turbinated, angulated towards their lower
portions, and flattened or slightly convex above the angle, the sutures are strongly marked,
ench'cliiig hues three, of which one is above and another beneath the angle ; these are
decussated by other lines perpendicular and smaller, forming tubercles more or less distinct
where they cross the angle, the decussating lines are distantly and sometimes irregularly
arranged ; the last volution has large, regular, concentric elevations ; the aperture is
pyriform.

An elegantly turbinated more or less lengthened shell, with convex volutions and a
delicately ornamented surface ; about a dozen specimens have been compared, which do not
vary much in size ; the length of the aperture is about two fifths of the entire shell. All
the examples are more or less imperfect at the base.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of AV. Walton, Esq.

Natica texata, Lye. Tab. XLV, figs. 30, 30 a.

Testa ovata, depressiuseula, crassa, spira anfractibus (3) patens, viw elevatis, convexis ;
anfractu ultimo injtato, basi umbilieato, apertura subreniformi, labro interno crasso ; superficie
striis vel lineis texatis delicatissimis ornata.

Shell ovate, depressed, thick, spire consisting of three depressed but exposed and
rounded volutions, the last volution much inflated, the base umbilicated, the aperture
somewhat reniform, the inner lip thick and conspicuous ; the surface with very delicate
encu-cling lines or striations, which are rendered granular by others decussating them.

ADDENDA. 97

Allied to Natica Montreuilensis, Heb. and Desl., from the Kelloway Rock of Montreul-
Bellay, which species, however, is less depressed and the aperture more lengthened.

The ornamentation of the surface in our shell is partially preserved, and can only be
perceived by the aid of magnifying power.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection of
W. Walton, Esq.

Natica arata. Tab. XLV, fig. 2.

Testa parva, crassa, infata, spira exserta, anfractibus (4) convexis, ultimo, permagno,
transverse striata, suturis valde impressis, apertura ovata, umbilico nullo.

Shell small, thick, inflated, spire produced, volutions (4) convex, the last volution very
large and globose, with delicate encircling striations, the sutures deeply impressed, the
aperture is ovate ; there is no umbilicus.

Geological Position and Locality. The Great Oolite of Bussage; collected by E.
Witchell, Esq.

Natica (Euspira) alta. Lye. Tab. XLV, figs. 22, 22 a.

Testa parva, lavigata, suhglohosa, sjjira elongata, apice acuto, anfractihiis (4) con-
vexis, latis, suturis valde wipressis, anfructu ultimo permagno, subgloboso, apertura ovata,
obliqua, subumbilicata.

Shell small, smooth, spire elevated, its apex pointed, volutions (4) convex, moderately
wide, the sutures strongly marked, slightly constricted, the last volution very large, sub-
globose, the aperture ovate, oblique, the inner lip prominent, the base with an umbilical
groove. The height of the aperture is slightly greater than that of the other portion of the
shell. Perhaps this is the young condition of a much larger species.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

Natica insignis. Lye. Tab. XLV, fig. 2L

Testa parva infiata, spira elevata, acuta, anfractibus (7) convexiusculis, angustis,
suturis bene impressis, anfractu ultimo permagno, subgloboso, apertura ovali, umbilico nullo.

Shell small, inflated, spire much elevated, its apex acute, volutions (7) moderately con-
vex, narrow, the latter two volutions increasing rapidly, and becoming much inflated, the
last volution is very large, subglobose, the aperture rather depressed, ovate, with no distinct
umbilicus, or with a slight groove.

13

98 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

The unusual number of the volutions and the sadden inflation of the last volution
renders its discrimination easy.

The height is about equal to the transverse diameter of the last volution.

GeoJoijical Position and Locality. Collected by E. Witchell, Esq., in the Great Oolite
of Bussage, near Bisley Common ; it has also occurred rarely in the Cornbrash of
Scarborough.

"RissoiNA SUBULATA, Ltjc. Tab. XLI, fig. 9.

Testa elonffata, subcylindrica, anfradiljus (9) convexis, cdtis, loiiyitudinaUter oblique
costellatis, costellis, crebris [circa 30 in ambitii), apertura ovato-obliqua, parva.

Shell elongated, subcylindrical, volutions (9) convex, high, longitudinally obliquely
costellated, costella3 closely arranged (about 30) in a volution; aperture ovate, oblique,
small.

A slender, subulate, delicately ornamented shell ; the height of the volutions is equal to
three fourths of their opposite diameter.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection of
W. Walton, Esq.

RissoiNA (?) TUMiDULA, Lyc. Tab. XLIV, fig. 13.

Testa ovato-tmnidtda Iceviyata, spira chvata, anfractibus (5) convexis, latis, suturis bene
distinctis, apertura ovata, antice angulata, labro externo crasso.

Shell ovate, inflated, smooth ; spire short, but elevated ; volutions (5) convex, wide,
their sutures deeply impressed ; aperture ovate ; the outer lip thick, forming an angle at
its junction with the base of the columella. There is no distinct notch.

A short, inflated species, resembling in the figure of the aperture B. lams. Sow., both
seeming to constitute aberrant examples of Rissoina, and approximating to Rissoa.

Geoloyical Position and Locality. Collected by E. Witchell, Esq., in the Great
Oolite of Bussage, near to Bisley Common, Gloucestershire.

Nerita clavatula, Lyc. Tab. XLV, fig. 3.

Testa hemispherica, spira parva, subdepressa, anfractu ultimo permayno, infato, taber-
culis parvis, remotiusculis, per series q/nnis, reyidarihis, et lineis radiantibus, tenuibus,
decussatis ; basi carina una, Iceviyata.

Shell hemispherical ; spire small, obtuse, and rather depressed ; the last volution very

ADDENDA. 99

large, inflated, with small depressed tubercles, rather remote, and arranged in fine
encircling rows, the rows of tubercles are connected by delicate radiating lines, one of
which is united to each tubercle; the base has a single, smooth, encircling keel; the
aperture and inner lip are similar to those of Nctifa minuta.

A pretty little and rare species, with the tubercles rather distantly arranged in each
row, they are somewhat lozenge-shaped or pointed posteriorly, about fourteen occupying
an entire volution.

Geolo(jical Position and Locality. The Great Oolite of Bussage, adjoining Bisley
Common, in the bed of white stone ; collected by E. Witchell, Esq.

Trochus Burtonensis, Lye. Tab. XLV, fig. IG.

Testa conica, lavigata, syira elevata, anfractibus (6), postice planatis antice concavis et
obti/se anyuJatis, anfractu ultimo basi leviter convexa, imperforata, aj^ertura subrotunda,
columella basi dcnte callosa.

Shell conical, smooth ; spire elevated ; volutions (0), their posterior portions flattened,
the anterior portions concave, bounded by an obtuse carina, the last volution has the
base slightly convex, imperforate, but with an umbilical depression ; the aperture is
rounded ; the base of the columella has a thickened dental process. Small specimens
have the spire less elevated, and the bounding carina much less prominent.

Geological Position and Locality. The Forest Marble of Burton Bradstock ; in the
collection of W. Walton, Esq.

Turbo depauperatus. Lye. Tab. XLV, fig. 13.

Pleukotomaria pagodus, var. depaupekata, Gr. Ool. Mon., Pal. Soc, 1850, part 1,
pi. 10, fig. 9, p. n.

The shell figured in the first part of this Monograph as a doubtful variety of
Pleurotomaria pagodus. Desk, has, by the aid of other specimens, been clearly shown to be
a different shell, which does not belong to the genus Pleurotomaria. Very few examples
have hitherto been obtained, all of which are more or less imperfect, have suffered com-
pression, or have been indifferently preserved ; however, by comparing one with another,
the distinctive characters have been fully ascertained.

A Forest Marble specimen, slightly compressed, is now figured ; compared with the
original of the former figure the spire is less elevated, the ornamentation of the surface
and of the base are better preserved.

The description formerly given applies to the species of Deslongchamps, the following
to Turbo depauperatus.

Testa turhinata, spira elevata, ajnce obtuse, anfractibus (5) convexis, imprimis inornatis.

100 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

aiifradu ultimo of penultimo in medio angulato, costis suhnodulosis cingendis, angulo ttibcr-
culis regularibus depressis coronatis ; hasi striis concentricis ei radiantihus decussatis,
umbilico patens, angulato, concentrice striata ; apertura depressa, sublunulata.

Shell turbinated ; spire elevated, its apex obtuse ; volutions (5), of which the first
three are rounded and without ornamentation, the two latter enlarge rapidly, are angulated
in their middle, and coronated with a row of regular depressed encircling tubercles, above
and beneath the angle are also three or four rows of nodulous encircling costse, of which
those beneath the angle are the most prominent ; the base is slightly convex, concentri-
cally and radiately striated ; there is an open umbilicus encircled by an angle, and
concentrically striated ; the aperture is depressed and sublunulate.

The last volution has the surface above the angle much flattened, and rendered rugose
by the nodulous elevations ; the encircling costs are closely arranged, somewhat irregular,
and become smaller towards the base of the last volution. In the specimen figured the
outer lip is imperfect.

Geological Positions and Localities. The Forest Marble of Laycock and Pound Pill ;
in the collection of W. Walton, Esq.

Turbo Burtonensis, Lgc. Tab. XLV, fig. 15.

Testa iurbinata, spira clevata, an/ractibus (4) convexis, cingillis tuberculosis tribus
magnis instructis ; ultimo anfractu basi cingillis (3 aut 4) ; apertura ovata, umbilico nulla.

Shell turbinated ; spire elevated ; volutions (4) convex, each encircled by three rows
of closely arranged large tubercles ; the last volution has at the base three or four con-
centric rows of smaller tubercles ; the apertvu'e is ovate ; there is no umbilicus.

The upper part of each volution is somewhat flattened, upon which is one row of
tubercles, the other two rows are more closely arranged ; the tubercles are large and
obtusely rounded. The basal transverse diameter is one fourth greater than the height.
It is allied to Turbo muricatus. Sow., but with a shorter spire, more constricted sutures,
and the tubercles much larger.

Geological Position and Locality. The Forest Marble of Burton Bradstock ; in the
collection of W. Walton, Esq.

Turbo subtexatus, Lye. Tab. XLI, figs. 15, 15 «.

Testa parva, injlata, spira elevata, anfractibus valde convexis, postice subhorizontalibus,
antice convexis, suturis profunde impressis, anfractu ultima permagna, apertura ovali,
umbilico nulla ; superficie lineis concentricis et longitudinalibus ienuisssimis, aut punctis vix
notatis.

ADDENDA. 101

Shell small, inflated ; spire elevated ; volutions (4) very convex, their posterior portions
nearly horizontal, their anterior portions convex, with the sutures deeply impressed ; the
last volution very large and ovate ; the aperture oval, no umbilical depression ; the surface,
vv^ith lines encircling and perpendicular, very densely and irregularly arranged, having
sometimes an imperfectly punctated aspect.

It is allied to Turho gihbosiis, D'Orb., but the latter is shorter and more inflated.

Geological Position and Locality. The Forest Marble of Farleigh ; in the collection
of W. Walton, Esq.

MoNODONTA COMMA, Lyc. Tab. XLY, figs. 24, 24 «.

Testa ovato-discoidca, ari/ractibus (4), elevatis, suhplanis, suturis disiinctis, anfractu
ultimo magno, apertura ellipfica, umhilico parvo, dente basili magna ohtuso ; siipcrfcie striis
concentricis tenidssimis, regularibus.

Shell ovate, discoidal ; spire elevated ; volutions (4) rather flattened, apex obtuse ; the
sutures distinct ; the last volution large, rather depressed, aperture elliptical ; umbilicus
small ; basal tooth large, obtuse ; the surface has very delicate, closely arranged, regular
encircling striations.

The general figure neai'ly approaches to Monodonta (Crossostoma) /ielic>/o)'ii/e, but the
latter shell is without ornamentation, and has a smaller and more depressed basal tooth
and sulcus.

Geological Position and Locality. The Forest Marble of Farleigh ; in the collection
of W. Walton, Esq.

Monodonta Waltoni, Lye. Tab. XLV, figs. 31, 31 «, b.

Testa crassa, ovoidea, teuuissime concentrice striata, spira brevi depressa, suturis
distinctis, anfractibus (5) angustis, subconvexis, anfractu ultimo permagno ; basi obliquo
subumbilicato, dcnte et sulco magno obtuso ; apertura ovata.

Shell thick, ovoidal, delicately concentrically striated ; spire short, depressed ; volu-
tions (5) narrow, sHghtly convex, their sutures distinct, the last volution very large, base
oblique, and slightly umbilicated ; the basal tooth and sulcus prominent; aperture ovate,
outer lip thick.

A pretty little delicately ornamented species, of twelve examples the smallest is
scarcely larger than the head of a pin, and has a distinct umbilicus ; the largest has a
diameter of four lines.

Geological Position and Locality. The Forest Marble of Farleigh ; in the cabinet of
W. Walton, Esq.

102 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

MouoDoNTA ARATA, Lijc. Tab. XLV, fig. 19.

Testa frocMformi, spira elevatu, anfractibus (6) latis, concavis, postice et antice carina,
striata, obtusa, suturis valde impressis, anfractibus semel concentrice tenuisslmc lineatis et
decussatim oblique striatis ; basi litieis concentricis majoribus et minoribus alternatis ;
sulco columellari magno et dente obtuso.

Shell trocliiform ; spire elevated ; volutions (6) wide, concave, having a striated obtuse
keel upon tlieir posterior and anterior borders ; there are also very delicate encircling
lines, which are indented by obhque decussating striations ; the base is concentrically
lineated, the Unes being alternately large and small ; there is also a conspicuous colu-
mellar groove and obtuse tooth ; the apertiu'e is nearly circular.

Height and basal diameter nearly equal.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

MONODONTA TEGULATA, Ll/C. Tab. XLV, flgS. 17, IS.

Testa sub-trochiformi, spira elaia, anfractibus (4), latis, in medio angulatis, carinis,
tribus cinr/endis, superne oblique planatis, inferne concavis^ anfractibus semel concentrice
lineatis, lineis granosis, striis tenuissimis decussatis ; basi concentrice lineatis, s/flco magno
mnbilicali et s/dco et dente obtuso instructo.

Shell sub-trochiform ; spire elevated, consisting of four wide and carinated volutions,
angulated in their middle portions by a prominent encircling keel, a keel being also
placed at the anterior and posterior border of each volution ; between the carina? are
numerous regular encircling lines, rendered granulated by decussating very fine oblique
striations ; the base is concentrically lineated, and has a large umbilical groove bounded
by a prominent keel ; the columellar sulcus and tooth are also conspicuous ; the aperture
is subcircular, its outer border impressed by the carinse.

The diameter at the base is one third greater than the height. A pretty species, with
strongly sculptured ornamentation. The volutions are obliquely flattened above and con-
cave beneath the median carina.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection
of W. Walton, Esq.

ADDENDA. 103

Genus — Onustus, HumjjJirei/.

Shell conical, with several volutions, which are flattened or are rendered somewhat
concave by an expansion of their lower borders, which overhang and conceal the suture ;
the lower border of the last volution is produced horizontally to support a membranous
expansion ; the surface has striations, or radiately undulating lines, which are somewhat
irregular. The base is concave towards the outer border, and convex towards the centre ;
the umbilical orifice is sometimes large, but in other instances small, and becomes nearly
concealed by advance of growth ; the aperture is depressed and ovate. Some Tertiary and
Recent species have the spire encrusted with fragments of shells or stones, which obscure
the ornamentation.

Xenophora, Fischer, and Phorus, Montfort, are synonyms of tliis genus.

OxrsTus BuRTOXENSis, L^c. Tab. XLV, figs. 1, 7 a, b.

Testa suhconica, sjpira elevafa, obfiisa, anfractibus (4-5), angustis subconcavis, longi-
tudinaliter costatis, cos/is (circa 24 — 26) inferne alfernatim in spinis producta ; basi sub-
concavo, concentrice et radiatim striato, umbilico amplo.

Shell subconical, wider than high ; spire moderately elevated obtuse ; volutions four
or five, narrow, slightly concave, with about twenty-four to twenty-six longitudinal rounded
and elevated costae ; the base of every alternate costa forms, with the lower expanded mar-
gin of each volution, a projecting process, which renders the lower margins of the volu-
tions undulated; the base is expanded, slightly concave, concentrically and radiately
striated ; the umbilicus is large.

A pretty species, possessing the generic features strongly defined, more especially the
expansions at the lower border of each volution, which impart a pagoda-like aspect to the
spu-e. Only two other British Jurassic species are known, viz , Trochus pyramidatus, Phil.,
= Trochus lamellosus D'Orb., a more depressed species, which occurs in the Supra-Liassic
sands, and in the Inferior Oolite of Gloucestershire and of Yorkshire ; the other is the
TrocJms ornatissimm, D'Orb., with a very elevated spire, and inordinately expanded at
the lower border ; it occurs in the Inferior Oolite of the Cotteswolds, and in the White
Oolite of Ponton, Lincolnshire. Our species is most nearly allied to Trochus oniatissimus,
but with a shorter spire, fewer volutions, and with prominent overwrapping expansions at
the lower border of each volution. Other foreign Jurassic species are Trochus heliaciis,
D'Orb., T. Tytirus, D'Orb., Solarium callaudianum , D'Orb., Onustus exul, Eug. Desk,
and Onustus liasinus, E. Desk None of these species exhibit those agglutinations of
shells and stones which are so characteristic of the Tertiary and Recent examples of
Onustus.

104 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Geological Position and Locality. The Forest Marble of Burton Bradstock ; in the
collection of W. Walton, Esq.

Phasianella variata, Lye. Tab. XLV, figs. 28, 28 a, h.

Testa ovato-elongata, spira aeuta^ anfractibirs (6-7), subconvexis, latiusculis,suturisvalde
impressis, ultimo a/ifractu amplo, aj)ertura ohliqua, ovato-elonyata.

Shell variable in figure, ovately elongated ; spire lengthened, with the apex acute ; volu-
tions six to seven, wide, more or less convex ; the sutures strongly impressed ; the last volu-
tions conformable, the aperture oblique, ovate, narrow, but always less than half the height
of the shell.

The variability in the convexity of the volutions and their height is considerable. The
general aspect resembles P. eleyans, Mor. and Lye, in which the spire is always less
pointed and less slender, the last volution being also longer.

Geologieal Position and Locality. The Forest Mi.rble of Layccck ; in the collection of
W. Walton, Esq.

Solarium turbiniformis, Lye. Tab. XLV, figs. 23, 23 a, b.

Testa turbinata, spira dextra, elevata, obtusa, anfractibus (4), tubercidis numerosis, coro-
natis ; basi convexa, umbilico mayno, maryinc, nodis {circa 9) cinyendo, siiperjicie lineis
transversalibus et lonyitudinalibus deeussatis ; ajjertura siiborbieulari.

Shell turbinated, spire dextral, elevated, volutions four, their borders coronated with a
circle of tubercles, about eighteen in a volution ; the base is convex, with a large and
deep umbilical cavity, bordered by large nodose elevations, about nine in the volution ; the
aperture is suborbicular ; the entire surface has encircling lines, with more narrow inter-
stitial spaces decussated and rendered granular by densely arranged transverse striations.

Allied to StraparoUus alius, D'Orb. ; the latter species, however, has the last volution
more elevated and the sides much more flattened, which impart a subquadrate figure to
the aperture ; the nodose elevations encircling the unibiUcus are also fewer and larger.

Geoloyical Position and Locality. The Great Oolite of Hampton Cliffs ; in the collec-
tion of W. Walton, Esq.

Solarium Waltoni, Lye. Tab. XLV, figs. 26, 26 a, b, c.

Testa discoidea, latere superiori et inferiori concavo, dorso anyusfo, convexo, tubereulis
per series duobus instructis ; latere superiori anfractibus subconcavis, varicibus obscuris

ADDENDA. 105

transversalibus instructis ; latere inferiore anfractibus planatls ; lineis transversalibus et
loncjitiidinalibus cancellatis ; aperfi/ra s/ibqnadrata.

Shell discoidal, the superior and inferior sides concave, the back narrow, rounded,
encircled upon its upper part by two rows of tubercles, of which there are about nineteen in
a volution ; the upper surface has the volutions slightly concave, and traversed transversely
by obscure varices, proceeding from the tubercles ; the lower side is but little more con-
cave than the other ; the volutions are flattened. The entire surface of the shell has deli-
cate transverse and encircling lines, forming a regularly reticulated surface ; the aperture
is subquadrate.

A beautiful and remarkably discoidal species.

Geological Position and Locality. The Great Oohte of Hampton Clifis ; in the collec-
tion of W. Walton, Esq.

Pleurotojiauia Bathonica, Lijc. Tab. XLV, fig. 10.

Testa trocldformi, conoidea, spira apice obtuso, anfractibus co7ivexis lineis transversis et
perpendicularibus, sub-csqualibus, cancellatis ; ultimo anfractu superne tuberculato-nodosis ;
sinu ma(/no, fascia sinus, plana, transversim lineata, in base anfractumn sita ; ultimo an-
fractu basi piano, concentrice lineato ; umbilico st/bnullo, apertura suhqi/adrafa.

Shell trochiform, conoidal ; spire obtuse j volutions convex, with cancellated transverse
and perpendicular lines ; the last volution with a row upon the upper part of nodose
tubercles ; the sinus is large, the fascia of the sinus is flattened and transversely lineated ;
the base is flattened, and concentrically lineated ; the aperture is subquadrate; there is no
umbilicus.

The encircling lines, of which there are three or four above the fascia of the sinus, are
more prominent than the perpendicular lines. The height is one third less than the basal
diameter.

Geological Position and Locality. The Forest Marble of the Box Tunnel, near Bath ;.
in the collection of W. Walton, Esq.

Pleurotomaria Burtonensis, Lye. Tab. XLV, fig. 8.

Testa trochiformi, conoidea, anfractibus (5 — 6), superne injlatis, nodoso-unaulatis, inferne
subplanis ; snperficie lineis transversalibus et perpendicularibus, (sqiialibus, dense cancellatis,
anfractu ultimo basi concentrice et radiatim lineatis, subconvexo, umbilico subnullo ; sinu
mayno, in medio anfractuum situ ; fascia sinus delicate cancellatis.

Shell trochiform, conoidal ; volutions (5 — G), very convex in their upper parts, and
nodosely undulated; their lower portions rather flattened; the surface, with encircling and

14

106 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

perpendicular equal lines, forming a delicately cancellated surface ; the last volution has
the base wide, somewhat convex, with regular concentric and radiating lines, the latter
being the less conspicuous ; there is scarcely any umbilical depression ; the sinus is large,
placed in the middle of the volutions ; the fascia of the sinus is delicately cancellated ; the
nodose elevations upon the upper half of each volution are regular, numerous, and not
very strongly defined in the greater nuuiber of the specimens.

The height is equal to two thirds of the basal diameter. Of the seven specimens
examined, the largest has a basal diameter of about an inch.

Geological Position and Locality. The Forest ]\Iarble of Burton Bradstock ; in the
collection of W. Walton, Esq.

Pleurotomaria recondita. Lye. Tab. XLV, fig. 7.

Testa trochiformi, discoidea, anfracfibm (4) subplanis, in/erne obtuse cariiiatis ; fascia
sinus lata, transverse delicate striata, in medio anfractum situ ; anfractibus cinyillis anyustis
(3 — 4) supra et infra sinus instructo, striis obliquis tenuissimis, impressis ; carina mar-
ginali leevi ; bctsi lato, concavo, vmbilicato, delicate concentrice striata.

Shell trochiforra, discoidal ; volutions (4) flattened, but rendered concave in the lower
portions by a prominent, obtuse, smooth, marginal carina; the fascia of the sinus is
mesial, wide, with very delicate transverse striations ; above and beneath the sinus are
three or four narrow encircling little costaj, which are impressed by delicate oblique stria-
tions ; the base is wide, concave, with a distinct umbilicus, with fine concentric striations ;
the outer lip and sinus have not been obtained perfect.

The height is equal to about three fifths of the basal diameter.

A small species, remarkable for the great breadth of the mesial band, and the pro-
minence of the infero-marginal smooth carina.

Geological Position and Locality. The Great Oolite of Bussage, near Bisley Common,
and of Minchinhampton Common ; it is rare.

AcTEONiNA LriDii, p. 27. Tab. XXXI, fig. 16, and Tab. XLI, fig. 18.

A fine series of examples kindly communicated by Mr. Walton, and collected by him
in the Forest Marble of Laycock, has enabled the artist to illustrate the more striking
varieties of figure. The differences in the elevation of the spire are so considerable that
any measurement of the spiral angle is useless ; the sides of the volutions are always
flattened, with a mesial angle ; in short spired examples the space anterior to the angle is
nearly concealed, and the space posterior to it is nearly horizontal.

Another remarkable instance of variability in the elevation of the spire in the same

ADDENDA. 107

genus is seen in A. olivtBformis, Tab. XLI, figs. 4, 4 a, which may be compared with that
given in Tab. VIII, fig. 14, part 1.

AcTEONiNA SuESSEA, L^c. Tab. XLV, fig. 29.

Testa ovafo-elonc/ata, spira elevata, apice acuminata anfradihus (7) angtistis, suhangu-
latis, superne concavis anfractu ultimo basi atteimato ; apertura obtiqua subreniforvii, labro
interna incrassato.

Shell ovately elongated ; spire elevated ; apex pointed ; volutions (7) narrow, convex,
subangiilated, their upper surfaces concave, their upper borders strongly impressed with
a slightly tumid band ; the last volution attenuated towards the base ; the aperture
oblique, and somewhat reniform ; the inner lip conspicuous and thickened ; the lines of
growth are very con.sipicuous upon the spire.

GeoJo(/ical Position and Localities. The Forest Marble at Farleigh, Laycock, and
Pound Pill ; in the collection of W. Walton, Esq.

ACTEONINA FASCIATA, Lyc. Tab. XLIV, fig. 15.

Testa parva, ovato-elon(/ata aut sub-cylindrica, spira magna elevata, anfractibiis (7)
angustis, superne convexis, inferne planatis, ultimo anfractu, valde elongato, apertura basi
elliptico curvato, postice angusto ; superjicie lineis plicisque perpendicularibiis crebris et
irregularibus notatis.

Shell small, ovately elongated or subcylindrical, the two extremities being somewhat
pointed ; spire large, lengthened, consisting of seven narrow volutions, which have their
upper portions inflated and their sides flattened ; the last volution is much elongated and
sub-cylindrical ; the aperture has its anterior extremity curved elliptically, its posterior
position narrow and lengthened ; the surface of the shell, with perpendicular, crowded,
irregular plications and lines.

The test is delicate, and all the specimens are more or less broken. Length of the
largest specimen, 6 lines ; breadth, 2 J lines ; length of the aperture, 4 lines.

Geological Position and Locality. The Forest Marble of Laycock ; in the collection of
W. Walton, Esq.

ACTEONINA WiLTONENSIS, Lyc. Tab. XLV, fig. 25.

Testa parva, sub-fusiformi, ovato-elongata, spira elata, anfractibus (5 — 6) siib-convexis,
anfractu ultimo ovato, apertura elliptica, basi angusto ; superficie lineis perpendicular ihus,
ienuissimis, crebris notatis.

108 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Shell small, sub-fusifomi or ovately elongated, spire elevated, volutions 5 or 6, rather
convex ; the last volution ovate ; aperture elliptical, its base narrow ; the surface, with very
delicate, closely arranged, perpendicular lines, -which render the surface slightly rough.

As the outer lip is much broken in both the specimens examined, the figure of the
anterior extremity of the aperture is rather doubtful, and the general figure of the shell is
more fusiform than is usual in this genus; the columella is rounded, and quite destitute
of any plication.

Geological Position and LocalUv. The Forest Marble of Laycock ; in the collection of
W. Walton, Esq.

OSTREA WiLTONEKSIS, Li/c. Tab. XXXIV, figs. \,\ a.

Testa, valva libera planata, crassa, solicla, ovato-trianc/idari, brevi,apice credo, ohtuso ;
sulco cardinis laio, superfciali. Valva qffixa ignota.

Shell with the free valve flattened, but solid and thick ; its borders are raised inter-
nally, rendering the inner surface somewhat concave ; the figure is ovately triangular, but
short, with the apex erect and obtuse; the hinge sulcus is wide and superficial. The
affixed valve is unknown.

Several large specimens of this ponderous but flattened oyster have been obtained by
Mr. Walton, including the monstrosity. Tab. XXXIV, fig. 1 a. The height is greater than
the opposite measurement ; it has some resemblance to 0. deltoidca, but less flattened, not
transverse, and with the umbones not oblique ; and as the specimens are constant in their
general characters, there can be no doubt of its distinctness from that species.
Geological Position and Localifg. — The Forest Marble of Pound Pill.

OsTREA (Exogyra) lingulata, WaJtoH MSS. Tab. XXXII, figs. 2, 2 a, 2 h.

Testa valva inferiore sublcevi, excavata, elongata, postice carinuta, margine anteriore
suhrecto, cardine brevi, antrorsum curvato. Valva libera jylanata, elongata, Ihiguaformi,
umboni compresso, arcuato ; facie interna sulco longitudinali oblique insfructo.

Shell, with the affixed valve excavated, elongated, smooth, with a posterior external,
longitudinal angle ; hinge margin short, and curved forwards ; anterior border straight,
posterior border curved elliptically. Free valve flattened, smooth, lengthened, and tongue-
shaped, tapering towards both the extremities ; the umbo is depressed, and much curved ;
the inner surface with a lengthened posterior sulcation The length is usually about twice
the opposite diameter.

A species allied to Exogyra carinata. Roemer X^ordd, Ool., p. 66, pi. 3, fig. 15.
This latter, however, appears to have the affixed valve more flattened and luuulate.

ADDENDA. 109

Geological Positions and Localities. This oyster appears to be abundant in tlie Upper
Bathonian Clays of Wiltshire. Mr. Walton has collected it in the Forest Marble of Pound
Pill, Farleigh, and Hinton, also in the Cornbrash of Ililperton.

Genus — Harpax — Parkinson, 1811. Deslongcharaps, 1858.

Shell irregular, inequivalve, attached by the umbo of the larger or right valve ; surface
radiately ribbed or smooth, usually with concentric, irregular, lamellose plications, imbricated
or tubercnlated ; borders of the valves close fitting and irregular.

Hinge in the attached valve consisting of a large, flattened, triangular plate, traversed
by a central perpendicular or oblique furrow to receive the ligament, with somewhat
elevated borders, exterior to which are slightly marked diverging sulcations to receive the
elevated borders of the ligamental groove in the other valve ; the outer borders of the
plate form lengthened and elevated dental processes.

Hinge in the left or free valve with a triangular plate traversed mesially by the liga-
mental groove, the borders to which are elevated and but slightly diverging; exterior to
these are strongly impressed grooves to receive the dental processes of the other valve ;
the dental processes forming the diverging borders of the plate are but little produced.

The hinge plate in each valve has transverse striations of growth.

The adductor scar is round, placed posterior to the middle of the valve, and strongly
marked ; the pallial sinus is simple.

The genus Harj^ax having originally been imperfectly described by Parkinson, and
founded upon a single small species, remained but little noticed and accepted by few
authors until the year 1858, when it was re-established and amply illustrated in a copious
work* on the ' Fossil Plicatulas and allied Genera,' by that eminent and veteran palaeon-
tologist M. Eudes, E. Dcslongchamps, who to the long list of memoirs in which he has so
ably developed and illustrated the Jurassic fossils of Normandy, has added the present,
which probably surpasses all the former in the critical acumen and lengthened researches
which it has necessitated. Of the fifteen species of Harpax known to M. Dcslongchamps
all are Liassic, with one exception (//. scajjJta), from the ferruginous (Inferior?) Oolite of
Longwy ; the following fine species is therefore the first example of the genus in the
oolites of this country.

* Essai sur les Plicatules fossiles et quclque autre genres voisins on demembres de ces coquilles,
par M. J. A. Eudes Deslongcharaps. Extract du Xle volume des ' Memoires de la Societe' Linneeune de
Normandie,' Caen, 1858.

no SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

Harpax Waltoni, Lye. Tab. XXXII, figs. \, \. a,\b.

Testa [valva dextra) magna, crassa, ovata, convexa, sub-auriculafa, late adherente,
radiatim costatis, lamellis incrementi crebris, crassis nodiferis ef imbricatis, facie inferno,
tabula cardinali magno dentibus et foveis longissimis iusigni. Valva sinistra depressa,
crassa, lamellis ut in valva altera, tabula cardinali dentibus prominentibus, longissimis,
obliquis, sulcis conformibus.

Shell of large dimensions, the right valve with a very large surface of attachment, sub-
auriculated, thick, ovate, convex, the surface radiately costated, with thickened, crowded,
imbricated and elevated lamellee of growth ; the triangular hinge plate is very large,
oblique, transversely striated ; the diverging outer grooves which receive the dental pro-
cesses of the other valve are large, deeply impressed, and exhibit in their course three
deeper portions or pits adapted to the successive positions occupied by the anterior pro-
jecting or bossed extremities of the dental processes in the free valve ; the adductor scar is
very large and posterior.

The left or free valve is thick, but less convex than the other ; the hinge area occupies
upwards of two fifths of the length of the valve ; the ligamental groove is narrow and
deeply marked, but the other furrows are superficial ; the outer diverging dental pro-
cesses are lengthened and conspicuous, terminating anteriorly in projecting bosses ; the
adductor scar is prominent and sub-central. In the specimen figured with the valves in
contact, the right valve has adhered to a smaller specimen of the same species, whose
exposed inner surface exhibits the usual characters of the left valve.

Our sjiecies is allied to Harpax calvus and H. senescens, Desk, from the Middle Lias
of Calvados, but has more prominent rugose lamellae, and a larger hinge area in both the
valves. In the left valve the anterior termination of the dental processes in bosses with
corresponding pits in the furrows of the other valve, has no counterpart in the figures or
descriptions of M. Deslongchamps, but as they do not appear to be equally persistent in
all specimens their importance can only be small.

Geological Positions and Localities. Tlie Forest Marble of Farleigh Wick, Somerset ;
collected by W. Walton, Esq., whose labours have been rewarded by the acquisition of
several good specimens. The interiors of the valves of this species have also been observed
in the Great Oolite of Minchinhampton ; in these instances, however, their external
surfaces could not be disengaged.

Gervillia Waltoni, Lgc. Tab. XXXII, figs. 4, 4 a, b.

Testa fragili, ovato-oblonga, valva sinistra antice convexa, postice explanata in alam
l)revem producta, umboni jjrominente, apice acuta, subterminali, ala antica brevi, margine

ADDENDA. Ill

curdinali obliquo, area cardinis longitudinaliter striatis, sidcis Iransversis magnis (4),
dentibiis obliquis internis panels inconspicuis ; superjicie plicis incrementi delicate instructis.
Valva altera mediocri convexa.

Shell fragile, ovately oblong; left valve anteriorly very convex, moderately thick,
and steep ; posterior side expanded, attenuated, and produced into a short wing ; umbo
prominent, acute, subterminal, the anterior wing being short ; the hinge margin is
oblique, of moderate length ; the hinge area has two or three prominent longitudinal
striations ; the cardinal transverse sulci, four in number, are large and irregular ; the
internal oblique teeth are few and inconspicuous ; the surface with numerous delicate plica-
tions of growth. The other valve is of nearly equal convexity and more strongly plicated.

A well marked convex species, with the hinge border moderately oblique, and the
whole of the posterior side expanded and delicate.

Geolo(/ical Position and Locality. The Forest Marble of Farleigh and Pound Pill ; in
the collection of W. Walton, Esq.

Gervillia CRN ATA, Lyc. Tab. XXXVI, fig. 7.

Testa jjarva, ovato obliqiia ; valva sinistra convexa, umboni pronmiente, ala antica
producta ; 2}0stica obliqua, brevissima ; superjicie striis tenuissimis concejitricis, reguluribus,
lineisque radiantibus decussatis. Valva altera ignota.

Shell small, ovately oblique; the left valve inflated, the umbo prominent and situated
nearly in the middle of the hinge line, which slopes from it obliquely in upon each side ;
the anterior wing is produced and rounded, the posterior wing is very short ; the surface
of the valve has very delicate, regular, concentric striations, which are decussated by
elevated lines which diverge from the umbo. The other valve is unknown.

A short, oblique, and very convex Gervillia ; the radiating lines upon the middle of
the valve are slightly undulating and conspicuous, but gradually disappear towards the
sides. The general figure is allied to G. ovafa, Sow., but the latter is less convex, and its
surface is destitute of ornamentation.

Length, 5 lines; breadth, 3 lines. Prom the position of the shell in our figure the
short posterior wing is not seen, and the convexity is scarcely sufficiently conspicuous.

Geological Position and locality. The Great Oolite of Bussage, adjoining Bisley
Common ; collected by E. Witchell, Esq.

Gervillia bicostata, Zyc. Tab. XL, fig. 21.

Testa per-obliqua, convexa, ala antica brevi, altera longiora, emarginata, dorso, costis
obliquis elevatis (2) distantibus, plicis incrementi mctgnis decussatis. Valva dextra
igtiota.

112 SUPPLEAIENT TO GREAT OOLITE MOLLUSCA.

Shell small, very oblique, convex ; the anterior wing short, thick, and gibbose ;
posterior wing more lengthened, emarginated posteriorly ; the niidille of the valve with
two elevated, oblique, longitudinal, distantly arranged costae, which are crossed by large
irregular folds of growth ; the right valve has not been obtained.

Oui' sole specimen has the posterior extremity imperfect.

Geological Position and Locality. The Great Oolite of Bussage, near Bisley
Common ; collected by E. Witchell, Esq.

Perna Mytiloides, Lam. Tab. XXX II, fig. 3.

Peena Mytiloides, LamarJ;. Au. sans Vert., 6 Bd., p. 142.

— — Zieten. Pet., p. 71, pi. 54, fig. 2.

— — Gold/. Pet., p. 104, t. 107, fig. 12.

— — B'Orb. Prodrome de Paleont, 1, p. 311, No. 211.

— — Morris. Catal., 1854, p. 179.

— — Oppel. Jura formation, p. 607, No. 79.

— — Quenstedt. Der Jura, p. 383, tab. 52, fig. 8.

— — Damon. Geol. Weymouth, Suppl., pi. 2, fig. 5.

Testa ovata-sipnoidea, convexo-plana in alain brevem producta, umbonibus acutis
prominentibus, margine cardinali obliquo,foveolis {8-12) plano-concavis.

Shell thick, ovately sigmoidal, with a moderate convexity, slightly produced pos-
teriorly into a short imperfect wing ; the hinge margin is wide, oblique with transverse
pits from eight to twelve in number, and only slightly impressed ; the anterior border of
the valves is much thickened and excavated.

Geological Positions and Localities. The Forest Marble of Farleigh ; in the cabinet
of W. Walton, Esq. Unfortunately none of the Forest Marble specimens are altogether
perfect. The Geological range of this Perna must be very considerable, if there is no
mistake in the identification of the species. Professor Quenstedt records it in the
Inferior Oolite of VVurtemburg; Goldfuss, in the Oxford Clay and Upper Oolite of
Baireuth and Wurtemburg; D'Orbigny quotes it from Villiers, TrouviUe, Lyon,
Chaumont, Pizieux, Marolles (Sarthe), and other localities in the same department,
all in his ' Etage Callovien.'

Mr. Damon has figured it from the Oxford Clay of Weymouth ; and it has been
recorded in the Kiiumeridge Clay of the latter place ; and the Portland Oolite of Swindon,
by Professor jMorris.

Perna obliqua, Walton MSS. Tab. XXXIV, fig. 22 a.

Testa subaquivalvi convexo-plana, crassa, umbonibus acutis, prominentibus, margine
anteriore recto, margine cardinali recto, oblique declivi, valvis lamcllis irregularibus

ADDENDA. 113

concentricis instrudis. Area cardinis angusta, elongata, foveolis (8) latis, suhcon-
cavis.

Shell subequilateral, moderately convex, slightly arched longitudinally in the left
valve ; test thick, iimbones acute and prominent ; anterior border straight ; hinge-border
moderately lengthened, straight, sloping obliquely downwards. Hinge-area narrow,
elongated, pits (8) wide, and only slightly concave; lamellae of growth large and
irregular.

Length, about twice as great as the transverse measurement ; diameter through the
valves, one third of the length.

Geological Fodiion and Locality. The Forest Marble of Gastard ; in the cabinet of
W. Walton, Esq.

Pecten subspinosus, ScJiloth. Tab. XL, fig. 14.

Pecten subspinosus, Schloth. Petref., p 223.

— — Gohlfuss. Petref., t. 90, fig. 4.

— — Quenst. Der Jura, p. 500, pi. 67, figs. 3, 4 ; and pi. 92, figs.

5, 6.

Testa ovato-orbiculari fornicata cequivalvi, costis (12) cequulibus elatis suhacutis in dorso
spinosis, sulcis conformihus transversim linealis, auriculis incequalibus costatis lineisque
decussantibus sfriatis. (Goldfuss.)

Shell ovately orbicular, equivalve; costse (12) large, elevated, subacute, each having
upon its ridge a few short spines ; the interstitial sulcations are narrow, with delicate,
transverse lines ; the auricles are unequal, the anterior auricle of the right valve being the
larger ; they have radiating and decussating lines. The valves have but little convexity ;
the radiating costse form one thii'd of a circle.

Height, 7 lines ; transverse diameter, 9 lines.

Geological Positions and Localities. The Forest Marble of Locus and Farleigh,
Somerset ; in the collection of W. Walton, Esq. The foreign localities cited by Professor
Quenstedt are Bopfingen and Waldenburg, in the Parkinsoni Oolite and the Bradford
Clay ; also Nattheim, in the Coralline Oolite.

Macrodon HiRSONENsis, var. rugosa. Tab. XXXVI, fig. 9.

The Forest Marble of Wilts and Somerset has this species in the form of a variety
which is distinguished from the shell of the Inferior and Great Oolite by the following
features: — It has greater convexity, a wider hinge-area; the posterior side is more de-
pressed, and is not uncommonly traversed by two or three radiating furrows, and is in
some instances separated from the other portion of the surface by a distinct keel. The

15

114 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

folds of growth upon the sides of the valves are also remarkably, conspicuous, rendering
the surface rugose, and the basal sinuation is very strongly defined ; in some of the more
aberrant forms the posterior side is so much shortened that the umbones are nearly
mesial ; they are then much elevated, and an oblique keel descends to the in fero- posterior
extremity. Our illustration faithfully represents this variety, numerous specimens of
which have been placed at our disposal by the kindness of Mr. Walton.

Cardium Gi,OBOsrM, Bean. Tab. XXXVin, figs. 2, 2 «, 2 b.

Cardium globosum, Bean, in Mag. of Nat. Hist, 1839, p. 60, fig. 18.

Testa suborbiculari, cequilatera, convexa, marffinibm ellipticis curvatis ; superfcie striis
concentricis, tenuissimis, crebris instructis.

Shell suborbicular, equilateral, convex ; the umbones moderately produced, acuminated,
and incurved ; the margins of the valves are elUptically curved ; the surface has very deli-
cate, regular, closely arranged, concentric striations.

The length and breadth are equal ; the diameter through the valves is two fifths less.
Our illustration is taken from the original specimen figured by Mr. Bean ; its outline
should be somewhat more orbicular. The striated surface readily distinguishes it from
Cardium cognaium, Phil., which in other respects it resembles.

Geological Position and Locality. The Cornbrash of Scarborough ; in the collection
of Mr. Leckenby.

LiTHODOMus PoRTERi, Li/c Tab. XL, fig. 29.

Testa parva ovato-oblonga, convexa, aiigmta, umbonibus obliquis, siibterminalibus ;
margine anteriore recto, posteriore elliptico curvato, costis longitudinalibus numerosis,
teni/ibus lineis concentricis decussatis.

Shell small, ovately oblong, narrow, convex ; umbones oblique, subtermiual ; anterior
border straight, its sides steep ; posterior margin curved eUiptically ; longitudinal costae
numerous, delicate, closely arranged, sometimes bifurcating towards the lower border, and
decussated by closely arranged, concentric lines.

The ornamentation is most prominent towards the middle of the valves, and is very
faintly traced upon the anterior side. It is allied to Lithodomus parasiticus. Desk, Mor.,
and Lye. (' Gr. Ool. Mon.,' "Biv.," p. 41, Tab. IV, fig. 19), but has greater convexity,
and is more narrow and cylindrical ; the numerous costse and decussating Hues are also
distinctive features.

Geological Position and Locality. Collected by W. "Walton, Esq., in the Great Oolite
of Hampton Clio's, near Bath.

Dedicated to Henry Porter, Esq., M.D., who has investigated the geology in the
neighbourhood of Peterborough.

NOTES AND CORRECTIONS.

Fossils figured in the former jmrts of tins Monograph from the Coast of Yorkshire, and

attributed to the Great Oolite.

It may uow be stated, as the general conviction of Palaeontologists who have critically studied the
subject, that the Testacea of all the marine beds intercalated with the important but local plant-bearing
shales and sandstones of the Yorkshire coast, intermediate the Cornbrash and the Dogger, constitute an
Inferior Oolite fauna, but that the mineral character of these deposits and their sequence are peculiar to the
locality ; it is found also, as might be expected in deposits so isolated in their general conditions, that the
fauna of these several marine beds, although undoubtedly pertaining to the Inferior Oolite, cannot be
arranged with precision upon any corresponding horizons of the same formation, either in Britain or upon
the Continent. But in discarding the correlative value of tlie minor subdivisions, it appears that they may
be assigned approximately to those groups of beds which constitute the upper portion of the Inferior
Oolite, and which have been divided by Quenstedt, Oppel, and others, into two distinct stages, the lower of
which is characterised by the presence of Ammonites IIumphriesia7ius, the upper by Ammonites Parhinsoni.
Upon the coast of Yorkshire these Ammonites, however, have occurred in the same bed, and the number of
marine floors is so few that they cannot be considered as representing the two superior stages in the
entity of their mass and of their fauna ; their deficiencies are more especially remarkable in the rarity of
the Brachiopoda and of the Ammonites.

These conclusions have been arrived at by an investigation of a series of details so extensive and
decisive in their results as to admit of no uncertainty upon the subject. That the marine beds in question
should have been assigned to the Great Oolite upwards of thirty years since by the author of the ' Geology
of Yorkshire ' will not excite surprise in any one who is able to recall to memory the rudimentary condition
of Palaeontology at that period, and the absolute ignorance which then prevailed of the Testacea of the
Great Oolite ; that the Palaeontology of the Jurassic portion of the work in question constituted a great
advance upon the previous work of Messrs. Young and Bird was at once recognised, and the author candidly
stated that he assigned these marine intercalated beds to the Great Oolite solely from their position — higher
than certain beds of undoubted Inferior Oolite, and lower than the Cornbrash. The progress of knowledge
tending to arrange them with the Inferior Oolite, was gradual. Following the work of Professor Phillips, in
1839 appeared the two well-known memoirs of Professor Williamson on the distribution of organic remains
in the Oohtic rocks of Yorkshire, in which the subordinate beds of the Lower Oolites and their organic

116 SUPPLEMENT TO GREAT OOLITE MOLLUSC A.

contents are detailed with all the care and precision that might be expected from a person who had been
long resident in the locality. Within the few years following appeared the elaborate works of Goldfuss,
Ziethen, Roemer, Dunker, Agassiz, Deshayes, Sir R. Murchison's second edition of the ' Geology of Chel-
tenham,' the ' Catalogue' of Professor Morris, the memoir of D'Archiac on the Aisne, several memoirs by M.
Eudes Deslongchamps on the fossils of the Oolites of Normandy, a portion of the ' Pale'ontologie Fran9aise '
of D'Orbigny, Quenstedt's ' Wurtemburg,' and the ' Lethea' of Bronn. These works, together with others
which bear less directly upon the subject of the Lower Oolites, tended very materially to extend and correct
the knowledge of their fossils. During the same period also the fossils of the Great Oolite in Gloucester-
shire had become extensively dispersed, and were compared with those from the Yorkshire coast, collected
and distributed with great perseverance by Mr. Bean during a lengthened period. Tbe first published
results of influences so potential appeared in 1850, when M. d'Orbigny, in his ' Prodrome de Paleontologie,'
placed many of the so-called Great Oolite Yorkshire fossils in his Etage Bajocien, or Inferior Oolite. In
the same year appeared the first part of the monograph on the Great Oolite MoUusca, in the introductory
remarks to which the authors pointed out the affinity of the Yorkshire so-called Great Oolite fauna to that
of the Inferior Oolite, and, as a measure of precaution, were careful to keep the doubtful Yorkshire fossils
distinct, both in plates and descriptions, from tbe Great Oolite fossils of the south of England. The various
works and lesser memoirs upon tbe Lower Jurassic rocks published between 1850 and the present time
would of themselves constitute a considerable list. Without enumerating them, it will be sufficient to
mention that, in 1856-8, Dr. Albert Oppel, in his remarkable work, ' Juraformation,' placed the Yorkshire
Phytiferous beds with the Inferior Oolite, and considered that they did not even represent the highest stage
of that formation. In 1857 the present writer expressed, in a little work, 'The Cotteswold Hills,' convic-
tions of similar import. In 1859 Dr. Wright enforced similar views, accompanied by extensive details and
lists of Inferior Oolite fossils, in a contribution to the ' Journal of tbe Geological Society.' The previous
Great Oolite Monograph contains four plates of these Yorkshire intercalated marine Testacea ; some of
which, however, pass upwards into the Great Oolite of the Cotteswolds and into the Cornbrash, as will be
ascertained from the descriptions. In excluding tiiem from the present Supplementary Monograph, the
writer begs to state that he consented to their admission into the former work with great reluctance, in
deference to the opinion then prevalent that they pertained to the Great Oolite, but with a strong impression
(formed in 1839, upon perusing the memoir of Professor Williamson) that they constituted an Inferior
Oolite fauna.

The Palaeontologists of France, in their expositions of the Great Oolite fossils of that country, have,
within the last few years, fuUy proved, by the general identity and association of species, that the fauna of
the Jlinchinhampton beds is not exceptional or local merely, as some have supposed, but represents a very
ample and characteristic series of Mollusca, a large number of which are also found in other and distant
localities at the same geological horizon. Other not less interesting and important facts, confirmatory of
this view, have recently been aff"orded by researches in English strata of the same epoch. The Oxfordshire
railway sections of the Great Oolite and Forest Marble have yielded to Mr. Whiteaves a varied series of
Testacea, a list of which he has kindly communicated to me, together with many of the fossils, including
those which are not known in the Minchinhampton beds ; the result is, that of 122 Great Oolite and 48
Forest Marble shells, in all 140 species, obtained by that gentleman in the Oxfordshire beds, upwards of
114 are also common to the Minchinhampton beds. An extensive series of Forest Marble shells from
the clay beds of Wiltshire, Somersetshire, and Dorsetshire, Uberally placed at my disposal by Mr. Walton,
has produced a larger number of novel forms, as might have been expected from the very different litho-
logical conditions of the deposit ; nevertheless there is still a majority of Minchinhampton shells, and the
entire assemblage is even more remotely allied to the Yorkshire fauna than is that of Minchinhampton.
The general discordance, therefore, of the Y'orkshire and southern faunas of the supposed Great Oohte
within so small an area as England would lead us to infer their separation chronologically, even if we were
unable to assign the northern series to that of an older and well-known era.

NOTES AND CORRECTIONS. 117

The following is a list of Yorkshire Testacea figured in the former Monograph which are not known to
occur in any stratum more recent than the gray limestone of Scarborough, and should therefore, in accord-
ance with the foregoing views, be excluded from the fauna of the Great Oolite :

Part I.

Ammonites Bbaikenridgii. Tab. XIV, fig. 1.

— Blagdeni. Tab. XIV, figs. 3 a, b.
Belemnites giganteus. Tab. XIV, figs. 4, 4 a.
Serpula pucatilis. Tab. XIV, figs. 5, 5 a, b.

— SULCATA. Tab. XIV, fig. 6.
Cerithicm Beanii. Tab. XV, fig. 5.
Chemnitzia (?) VETUSTA. Tab. XV, fig. 7.

SCARBURGENSIS. Tab. XV, fig. 8.

ACT.SON Sedgvici. Tab. XV, figs. 9, 9 a.

— VCLLUS. Tab. XV, fig. 11.
Acteonina glabra. Tab. XV, fig. 10.

— TUMiuuLA. Tab. XV, fig. 14.
Phasiavella latiusccla. Tab. XV, fig. 16.
Natica adducta. Tab. XV, figs. 17, 17 a.

— (Euspira) cincta. Tab. XV, fig. 20.
Teochus Leckenbyi. Tab. XV, figs. 21, 21a.

Part II.

Mttilus (Modiola) Leckenbyi. Tab. XIV, fig. 9.
Cucl'll.'Ea cancellata. Tab. XIV, fig. 12.
Unicaedium gibbosum. Tab. XIV, fig. U.
Trigonia signata — decorata. Tab. XV, fig. 1.
Astarte elegans, Phil, (non Sow.). Tab. XIV, fig. 14.
ISOCAHDIA CORDATA. Tab. XV, fig. 5.
Myacites Beanii. Tab. XV, figs. \\a, b.

— SCARBURGENSIS. Tab. XV, fig. 13.

— ^QUATUS. Tab. XII, fig. 1.5.

Cornhrash of the Coast of Yorkshire : its MoUusca.

The Mollusca of the Yorkshire Cornhrash offer, in their association, some marked contrasts with those of
the southern counties and of the Continent upon the same geological horizon. In the southern localities
the marine floors, crowded almost exclusively with Brachiopoda, is the predominating feature that arrests
the attention ; in the northern the Conchifera constitute the great majority ; the Brachiopoda, few indivi-
dually, are reduced almost to the two species Terehratuhi lagenalis and T. ohovata, the latter being
represented by forms dwarfed to about a third of the linear dimensions which the species attains in
Wiltshire. The condition of the Testacea also offers some interesting contrasts. In Wiltshire the
Conchifera are usually in the condition of casts, of which a large proportion are compressed and distorted ;
in Yorkshire the hard, dark-coloured limestone has preserved the more delicate external characters in a very

118 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

perfect manner, including the thin tests of Pholadomya, Myacites, Gresslya, Goniomya, and Cercomya,
together with the outer, granulated tegument of the four latter genera ; and when the matrix is less hard,
even their internal hinge characters may be disclosed. The Gasteropoda are few, both as to species and
individuals ; the Cephalopoda are, with the exception of a small Belemnite, limited to Ammonites macro-
cephalus, which affords great variety in the details of its figure and ornamentation, but which never attains
to the large dimensions of Wiltshire specimens.

Its Mollusca, viewed comprehensively, may be regarded as a transitive series, a chain of life serving to
connect the fauna of the Inferior Oolite with that of the Oxfordian rocks, comprising a considerable
proportion of the former, perhaps an equal number of special forms, a much smaller number of species
which pass upwards into the Oxfordian beds, and a still lessening proportion of forms which are recognised
in the Great Oolite or Forest Marble, but these latter consist almost entirely of shells which pass upwards
from the Inferior Oolite.

Minute Testacea of the Great Oolite and Forest Marble.

Only a portion of these have been selected for illustration, others, inconveniently minute, having been
rejected upon that account. That some of these minute forms attain to much larger dimensions under
different conditions may be inferred from the fact that many minute Gasteropoda and Conchifera associated
with them are only dwarfed forms of well-known Great Oolite species, which in other beds are of the
dimensions figured in the former parts of this Monograph.

Forest Marble Testacea.

The following note, kindly communicated by Mr. Walton, describes the localities of the Forest Marble
cited in this Monograph ;

" The principal localities from which these fossils have been obtained are Farleigh, Hungerford, in
Somersetshire ; Pound Pill, near Corsham, and Laycock, in Wiltshire ; and Burton Bradstock, about five
miles from Bridport. The lithological character of the Forest Marble is very various, demonstrating the
littoral character of the deposit, which is shown also by the trails of animals and the numerous remains of
what can hardly be anything but Fucoids. The best locality at Farleigh is a superficial cutting opposite
Wick Farmhouse, made in forming the new Warminster Road, and the bed is a crumbly, shelly marl, and
the fossils, when first found, apparently mere lumps of clay. In the small quarries near Hinton Charter-
house, Cumberwell, and Philips Norton, the rock is a hard, calcareo-arenaceous stone, and at Pound Pill
it is as hard and more intractable than Carboniferous limestone. At the railroad-cutting near Laycock it
is a cream-coloured clay, containing shells better preserved than usual, and from this nearly all the small
shells have been procured. In many places the Forest Marble is a mere mass of broken shells, and
frequently formed almost exclusively of crushed Rhynchonellae. At Burton Bradstock the Forest
Marble clay rests on the lower beds of the Inferior Oolite, and most of the fossils from that locality were
picked up from a bank on the sea-shore. I have never found an Ammonite in the Forest Marble, and only
one very doubtful trace in the Cornbrash."

Testacea from the Chujs of the Forest Marble coynpared with those from the Limestones of the Great
Oolite. — As might be anticipated from the widely differing mineral conditions of the two deposits, they are
tenanted to a great extent by different races of JIolluscs. The fossils figured in this Supplement from the
Forest Marble by no means represent the whole of the additional species contained in the clay beds of that
stage, but such only as from their state of preservation are suitable for our plates ; a large proportion have

NOTES AND CORRECTIONS.

119

suffered from vertical compression and consequent distortion, so that in many instances it has only been
possible, even with the choice of numerous specimens, to select one or two as representatives of their
respective species, and some tablets covered with shells have with reluctance been rejected when specific
forms could only have been made up by the aid of doubtful restorations. Our note on the age of the
gray limestone of the Yorkshire coast alludes to the general identity of species which obtains between the
Testacea of the Great Oolite and Forest Marble limestones of Gloucestershire and of Oxfordshire ; they
form, in fact, but one fauna, the most prominent species of which are abundant only over very limited
areas. In the Forest Marble days we find that the great mass of the organic forms belong to but few
genera ; the deficiencies in this respect are very striking. The large collection of Mr. Walton contains not a
single Ammonite or Belemnite ; of Gasteropoda there is almost an entire absence of Nerinsea, Cylindrites,
Ceritella, and Trocholoma, genera so abundant and varied in the limestones ; these deficiencies are to a
great extent compensated for by an abundance of special forms of Phasianella and of Acteonina, which is
the more remarkable as the latter genus is everywhere one of the most rare forms of the limestones. The
genus Cerithium is abundant, consisting of forms less dwarfed than is usually seen in the limestones. The
genera Nerita, Trochus, and Monodonta, are well represented, but the two latter genera for the most part
by forms special to the clays. Of the Conchifera the clays produce Tancredia comparatively in small
numbers and apparently of few species, but their condition is usually such as will not admit of a rigid
scrutiny ; a similar paucity applies to the Areas, Trigonias, Limas, and Pectens. Perna, Gervillia,
Pteroperna, and Astarte, are for the most part represented by species special to the clays or rare in the
limestones ; Pholadomya, Homomya, Myacites, and Goniomya, appear to constitute the rarest generic forms
in the deposit ; Cercomya and Thracia, perhaps, are absent altogether. Wanting these, the clay banks
swarmed with a profusion of Nuculas and CypriuEe, usually of forms differing from those of the limestones.
Perhaps about 25 per cent, would be a fair estimate of the testaceous species special to the clays ;
but taking only the more common forms of each deposit, the differences between them are much more
marked and important than would be inferred from such a proportion of species.

The following, probably, have not been obtained iu any other deposit than the Forest Marble :

Turbo Burtonensis.
subtesata.
nodifera.
Trochus Burtonensis.
Monodonta comma.
Waltoni.
arata.
tegulata.
Onusbus Burtonensis.
Natica arata.
texata.
alta.
Acteonina Luidii.
Suessea.
fasciata.
Wiltonensis.
Phasianella variata.
Solarium turbiniformis.
Waltoni.

Pleurotomaria Bathonica.
Ostrea Wiltonensis.
Gervillia Waltoni.
Perna obliqua.
Trigonia arata.
Lucina Burtonensis.
Corbis rotunda.
Corbula Hulliaua.

Islipensis.

Agatha.
Corbicella subangulata.
Cypriua bella.

Davidsoni.
Astarte robusta.

rustica.

fimbriata.

ignota.

Hilpertonensis,

Alaria parmda, p. 22. Tab. Ill, fig. 12 ; and A. cirrus, p. 22. Tab. Ill, fig. 13.

Further observations lead to the conclusion that the former shell is the young condition of the latter,

120 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

and that the differences in the last volution are owing only to the stage of growth to which the specimens
have respectively attained.

Index to Tab. XII, Part II, add figs. 13, 13 a, Hinge of Corbicella.

Page 95, fifth line from the bottom, add, and Tab. XII, figs. 13, 13 a.

Index to Tab. XIII, fig. 16, /or p. 139, read p. 140.

Myoconcha Actceon, p. 77, Part II, /or Tab. Ill read Tab. IV.

Tab. XIII, fig. 18, Part II, alter the reference to, Pholas costellata, p. 142.

Index to Part II, add, Pholas oolitica, p. 126. Tab. IX, fig. 21.

Alaria trifida. Part I, p. 21, add the following to the description: — The first two or three
volutions are longitudinally costated, the transverse striations extend even upon the caudal and digital
processes.

Pholodomya oblita, Part II, p. 142* ; Tab. XII, fig. S. It is now ascertained that the specimen figured
was erroneously assigned to the Great Oolite ; its true position is in seams of sandy marl near to the base of
the Inferior Oolite, in which position it occurs at various localities in the vicinity of Stroud and Nailsworth ;
the officers of the Ordnance Geological Survey have also procured it from a similar position in Somer-
setshire. It sometimes attains very large dimensions, as is exemplified by a remarkable specimen in the
Bristol Museum, which has been mistaken, as in other instances, for the aged condition of Pholadomya
fidicula, Sow. The delicate, radiating lines are scarcely distinguishable upon the aged and inflated
examples of P. oblita, but are always acute and conspicuous upon P.fidicula.

Trigonia decorata, Lye, Part II, p. 133, Tab. XV, fig. 1, alter the title to Trigonia signata, Ag., a
fine species, abundant in the Upper Trigonia Grit of the Inferior Oolite in the Cotteswolds, and more
rarely in the gray limestone of the coast of Yorkshire ; it occurs in a similar geological position at various
Continental localities. Professor Quenstedt has figured it from Wartemberg under the name of Trigonia
clavellata. It has never been found to pass upwards into the Great Oolite.

Patella paradoxa. Part I, p. 90, Tab. XII, fig. 2. This rare species is the Patella lata. Sow., 'Min.
Con.,' t. 484, fig. 1, p. 133. The compressed and imperfect specimen figured in the latter work will
account for our having failed at an earlier period to identify it with the very few examples which have been
obtained at Minchiuhampton.

Tancredia curtansata, Part II, p. 93, Tab. XIII, figs. 7, 7 a, 7 b, alter the title to Tancredia sub-
curtansata ; it is much less inflated, the umbones are more elevated and pointed, the posterior side is more
produced, and it is destitute of the large longitudinal plications which distinguish the species of the Coral
Rag; the latter is also a much larger shell, only two specimens of which have come to my knowledge, the
type specimen in the York Museum, the other in the fine collection of Mr. Leckenby at Scarborough.
Tancredia Lycetti, Oppel, from the Inferior Oolite of Wurtemberg and of Gloucestershire, is also nearly
allied to the Coral Eag shell, and appears to be equally rare.

Tancredia axiniformis, p. 93, Tab. XIII, fig. 6, and Tab. XII, fig. 7, alter the title to Tancredia
extensa, Lye. In this instance the name proposed in my first notice of the Genus Tancredia, 'Ann. and
Mag. Nat. Hist.,' Dec, 1850, must be retained, as an examination of many Yorkshire specimens of
T. axiniformis leaves no doubt that it is a distinct species, which occurs in the Inferior Oolite, both in that
county and in Gloucestershire ; compared with the Great Oolite T. extensa, it is shorter, more flattened,
approaching more nearly to the outline of T. brevis, but with much less convexity.

Tab. XV, Part II, figs. 2, 2 a, alter the title to Ceromya Bajociana, D'Orb. ; the figure represents the
usual size attained by this Ceromya in the Inferior Oolite of the Yorkshire coast ; in the Cotteswolds the
same formation produces it of far larger dimensions, and justifies the terms in which it is described by
D'Orbigny in his 'Prodrome,' p. 274, as follows : — "Magnifique espfece courte, renflee a crochets tres-

NOTES AND CORRECTIONS. 121

contourn^s, ornfee de stries concentriques d'accroisement, comme rostree a la region anale." It is the
Isocardia concentrica of Phillips, 'Geol. York.,' i, pi. .^i, fig. 40, but not of Sowerby. The Yorkshire
examples may, therefore, be considered as dwarfed forms of this really magnificent shell, the southern
examples of which have the distinguishing features of the species much more strongly marked ; the umbones,
more especially, are larger and more elevated, the posterior extremity being also more rostrated. It
is worthy of remark that this degenerated form is the only one of the genus that has been obtained from
the whole of the Jurassic rocks of Yorkshire.

Anatina undulata and Anatina plicafe/la, Tab. II, Part II, transpose figs. 6 and -1 upon the tab, ;
the references to them at p. 118, and also upon the page facing the tab., will then be correct.

Pholadormja ovulurn. Part II, Tab. XIII, fig. 12, alter the title to Pholadomya oralis, Sow. ; also at
p. 122.

7'urbo capitaneus, Goldf., Part I, p. 65, erase the words "Tab. IX, fig. 33," and alter to "Supplement.
Tab. XLI, fig. 1." The index to Tab. IX, fig. 33, should be altered to Amberleya Jurassi, Supplement,
p. 19.

Stomatia? Buvignieri, Part I, p. 85, alter the generic title to Nerita. Another figure is given,
Supplement, Tab. XLI, fig. 7-

Part II, Tab. VI, fig. 15, p. 67. I agree with Dr. Oppel (' Juraformation,' p. 487) in the propriety
of separating this Lucina from L. Bellona ; its title should, therefore, be Lucina Lycetti, as suggested by
Dr. Oppel.

Cerithium Roissii, Part I, p. 32, alter the generic title to Fibula. See p. 10 of this Supplement.

Myacites crassivsculus, Part I, p. 112, alter the generic title to Homomya. See p. 89 of this Supple-
ment.

Myacites Vezelayi, Part I, p. ill, alter the generic title to Homomya. See p. 88 of this Supplement.

Myacites gibbosns, Part I, p. 138, alter the generic title to Homomya. See p. 88 of this Supplement.

Corbiila involuta, Part I, p. 97, alter the title to Corbula Btic/cmani. See p. 63 of this Supplement.
Corbula Btichnani will be found refigured, Tab. XXXIV, figs. 6, 6 a.

Part II, p. 123, erase the first reference to Pholadomya Samanni, Tab. II, fig. 1, which is P.
solitaria.

Part II, p. 28, Tab. IV, fig. 12. This little shell, erroneously ascribed to the Modiola pidcherrima of
Eoemer, has been rectified by Professor Morris, ' Catal.,' p. 210, under the appellation of M. Lycetti.
Compared with the allied species of the Ililsthone, it is smaller, more inflated, the radiating lines are more
narrow or more distantly arranged, the test is very thin, and the specimens are usually imperfect.

Mytilus {Modiola) tumidus. Part II, p. 37, Tab. IV, fig. 5. It is stated that the rtide figure of a
Modiola, Young and Bird, ' Geol. York. Coast,' pi. vii, fig. 10, is intended to represent this shell, and
that Professor Phillips inserted it in his list of Yorkshire fossils, 'Geol. York.,' i, p. 171, in the following
terms : — " Modiola ungulata, Coralline Great and Inferior Oolite." It is not uncommon in the upper stage
of the Inferior Oolite in the Cotteswold Hills.

Purpuroidea Moreavsea, Part I, p. 27, Tab. IV, figs. 1 — 4, alter the title to P. Morrisea. The
publication of the splendid work of M. Buvignier on the Palseontology of the Meuse has shown that we
were mistaken in assigning our Minchinhampton species to that figured in a very indifferent manner in
the little memoir by M. Buvignier in 1843. The new specific name selected for our shell by the latter
author should therefore be adopted.

Part I, Tab. II, figs. 3, 3 a, p. 12. The Ammonite obtained at the base of the Great Oolite, and
referred doubtfully to A. macrocephalus, is now ascertained to be A. ivw/or, D'Orb., ' Pal. Fr. Terr. Jurass.,'

16

122 SUPPLEMENT TO GREAT OOLITE MOLLUSCA.

tab. 172, of wliicli numerous specimens are now in the British Museum, obtained from a similar geological
position in Somersetshire ; in some of these the last volution quite conceals all the others, leaving only a
small iimbilical orifice; the absence of costse upon the inner portion of the last volution distinguishes it
from A. macrocephahis. Dr. Oppel (' Juraformation,' p. 478) proposes for it the new title of A. Morrisii,
which, in accordance with the above views, must remain as a synonym of A. viator.

Acteonina? parvuh, Part I, p. 104, alter the generic title to Ceritella.

Part II, Tab. 5, figs. 18 a, 19 a. Both these figures represent the young condition of Trigonia
Goldfusdi.

Trochus pileulus, Part I, p. 66, Tab. 10, fig. 5. Additional specimens have proved that the smooth-
ness of the surface is accidental; traces of encircling striations are sometimes visible; the shell then
becomes identical with Turlo ohtusus, Sow., of which Trochus Bixa, D'Orb., is also a synonym.

Nerita hemispherica, Roem., Tab XI, figs. 14, 16; Nerita mtnuta, Sow., Tab. XI, fig. 19. A com-
parison of very ample materials, including all the connecting forms, leaves no choice but to regard iV-
hemispherica as the adult shell of N. minutu. The preservation of the epidermal pattern of coloration has
materially tended to this result; the older shells, as in fig. 14, with their strong, rugose plications, thickened
columelJar lip, and entire absence of the epidermal coat, appear at first sight sufficiently distinct, but from
these we pass to specimens of less advanced growth, as in fig. 16, without plications, but still possessing
the callosity upon the inner lip ; some in this state, however, retain portions of the external tegument, in
which may be traced remains of the two broad bands of white between the three of dark-coloured pigment,
the latter consisting of transverse, wrinkled lines. From these to the smallest forms the transition is easy ;
the latter are most commonly more ovate, but this is by no means an invariable feature, nor are the adult
shells very constant in the degree in which the spire is produced. The minute forms, which usually retain
tiie epidermal coat, are smooth and shining ; with advance of growth the shell exhibits continual and
considerable increase of thickness. The two extremes of aspect are fairly represented in figs. 14 and 19.
Nerita minuta is so inappropriate a name for the adult shell, that it seems desirable to adopt Nerita
hemispherica, although the former has priority.

Fitsus ? suhnodulosus. Part I, Tab. V, fig. 9, p. 23, alter the generic title to Brachytretna.

Phasianella conica, Part I, Tab. XI, fig. 30, p. 74 ; Phasianella acutiuscula, Tab. XI, fig. 28, and
Tab. IX, fig. 2. An examination of numerous additional specimens has led to the conclusion that these
forms should be regarded as only varieties of one species . for although some examples are even more
lengthened than the figures of P. acutiuscula, others connect the typical specimens of each variety in a
very perfect manner.

Genus Brachytrema, Part I, p. 24. Further information has shown that the generic description before
given should be slightly modified ; the outer lip was stated to be thin, which is correct as far as regards the
greater number of specimens ; but some species, as B. varicosa and B. pygmea, acquired at certain arrests
of growth thickened outer lips or varices, as in Triton ; from the latter genus they are distinguished by the
j-horter trochiform spire and absence of denticulations upon the borders of the aperture.

Turbo ? pygmeus, Tab. IX, Part I, figs. 29, 29 a, alter the title to Brachytrema pygmea. The doubt
as to the genus expressed in Part I, p. 65, has been justified in an example with the aperture perfect, figured
by M. Piette, 'Bull, de la Soc. Geol. de France,' 2 ser., pi. xv, fig. 21, under the name of Brachytrema
brevis ; the base is strongly striated, and the aperture much contracted.

Alaria IcEvigata, p. 17, Tab. Ill, figs. 3, 3a; Tab. XLI, fig. 13, alter the title to Alaria Myurus,
Desl., sp. It was stated at p. 17 " that in everything excepting its smooth surface this shell agrees with the
Rostellaria Myurus of Deslongchamps." A specimen recently obtained exhibits some encircling striations
upon the upper portions of the two larger volutions; the sole distinction, therefore, that separated it from

NOTES AND CORRECTIONS. 123

the species of Deslongcharaps is thus removed. The specimen figured Tab. XLI, fig. 13, exhibits the first
spine, which is monodactyle ; a second and much larger spine, also monodactyle ; the third and ultimate
spine being didactyle.

Aeteonina ?, Part I, Tab. VIII, fig. 12*, is the young shell of A. olivaformis, p. 103.

Lima Luciencis, D'Orb., 'Gr. Ool. Mon.,' Part II, p. 28, Tab. Ill, fig. 4. This shell is a synonym of
Lima rudis, Sow. The number of costse vary from eight to eleven ; the specimen figured in the ' Mineral
Conchology,' tab. 214, has only seven costfe, and the figure is unusually gibbose. Its geological range is
considerable ; it occurs sparingly in the Great Oolite of the Minchinhampton district and in the Cornbrash
of the coast of Yorkshire, but in the Coral Rag of Malton it is moderately abundant.

Sub-genus Crossostoma, Part I, p. 72. Of the three Oolitic species assigned to this proposed sub-genus
of Delphiuula, the only one which exhibits the distinctive characters is C. Pratii ; the other two forms,
discoideum and heliciforme, were formerly supposed to represent in their apertures the immature condition
of that sub-genus. Subsequent observations of numerous specimens has compelled me to abandon that view,
and to I'egard discoideum and heliciforme as adult shells, or discoidal forms of smooth Monodouta. Other
examples of Monodonta allied to the Great Oolite forms, but less depressed, have been figured by Messrs.
Hebert aud Deslongchamps, in their ' Memoir on the Kelloway Rock Fossils of Montreuil-Bellay,' under
the names of Monodonta ovulata and papillata.

Cerithium qMadricinctum, Goldf., and C. limceforme, Roem. These two forms must be united into one
species ; individuals with large nodules and with only three distinct rows have been assigned to C lima-
forme, but, even with these, indications of a fourth row are occasionally to be discovered, and the promi-
nence of the nodules, and their number in each volution, are very variable. C quadrieinctum has a
considerable geological range, and it occurs also in the Coral Rag of Germany.

Patella suprajurensis, Part I, p. 92, Tab. XII, figs. 9, 9 a. I can now only regard this form as a variety
of P. Aubentonensis, in which the lamellae of growth are strongly marked and the cancellated lines have
disappeared. It is also not uncommon to meet with smooth examples of the latter species.

Pholadomya solitaria, Part II, p. 124, Tab. XI, fig. 1, et Tab. XII, fig. 2 ; erroneously printed P. oblita
upon the reference facing the latter table. Pholadomya oblita is Tab. XII, fig. 5, p. 142*. The variations
of figure and of ornamentation, either separately or combined, are so considerable in the cordiform examples
of Pholadomya, that a large number are indispensable to enable us to legislate upon tliem with any
confidence ; probably P. solitaria is only a variety of P. deltoidea, Sow.

v^\

[Note. — The Author desires to tender his best thanks to Mr. West for the very careful drawings in the
plates tliat illustrate this Monograph ; and more especially for the fidelity and attention to
the more minute details exhibited in the magnified figures of the smaller Gasteropoda,
from the Great Oolite and Forest Marble.]

INDEX

TO

SPECIES RETAINED IN THIS SUPPLEMENT.

page table

AcTEON Bathoniciim

25 ... .

. XLIV, fig. 16.

— phaaianoides

26

. XLIV, fig. 28.

AcTEONiNA brevis

26

. XLI, fig. 6.

— canaliculata

27

. XXXI, figs. 9, 9 a.

— ■ fasciata

... 107

. XLIV, fig. 15.

— Kirklingtonensis

2G

XLI, fig. 5.

— Luidii ...

27, 106

. XXXI, fig. 16; XLI, fi

— scalaris ...

28

. XLIV, fig. 18.

— Scarburgensis ...

28

XXXI, figs. 13, 13 a.

— Suessea

... 107

XLV, fig. 29.

— Wiltonensis

107

XLV, fig. 25.

Ahberleya armigera

20

XXXI, fig. 6.

— capitanea

95

. XLI, fig. 1.

— Jurassi

19

IX, figs. 33, 33 a.

— monilifera

95

XLI, fig. 10.

— tricincta

96

XLI, fig. 14.

Ammonites buUatus

3

XXXI, fig. 1.

— discus ...

4

XLI, figs. 8, 8 a.

Brachytrema buccinoidea

5

. XLIV, fig. 17.

— varicosa

5

XLIV, fig. 27.

Ceiutella fusiformis

12

. XLV, fig. 4.

— Lycettea

12

XLIV, fig. 25.

— Morrisea

12

. XLIV, fig. 22.

— minutissima

11

. XLV, fig. 5.

Cerithium Bathonicum

6

XLIV, fig. 19.

— biilimoides

7

XLIV, fig. 3.

— compositum

—

. XLIV, fig. 9.

costigerura

93

XLI, figs. 11, 11 0, i.

— hemicinctum ...

91

.. XLI, fig. 17.

— multiforme

7

XLIV, fig. 20.

IS.

126

INDEX.

PAGE

TABLE

Ceeithium exscalptum

93 ...

... XLIV, fig. 23.

— ? neglectum

92 ...

... XLIV, fig. 21.

— poculum

93 ...

... XLI, fig. 24.

— undulatum

8 ...

... XLIV, fig. 6.

— Witchelli

10 ...

... XLIV, fig. 7.

— Waltoni

92

... XLI, fig. 16.

Cylinmeites exigua

24 ...

... XLIV, fig. 14.

— turriculatus ...

25 ...

... XLIV, figs. 26, 26 fl.

Chemnitzia constricta

15 ...

... XLIV, fig. 8.

— vitlata

14 ...

... XXXI, fig. 10.

Dentalium eutaloides

28 ...

... XXXI, figs. 11, 11 «, 11 6.

EuLiMA? laevigata

13 ...

... XXXL fig. 3.

Fibula eulimoides

17 ...

... XXXI, fig. 5.

— variata

16 ...

... XXXL figs. 4, 4 a.

KiLVEETiA composita

9 ...

... XLIV, fig. 9.

— formosa

95 ..

... XLIV, fig. 5.

— pulcbra

... 10, 94 ...

... XLI, figs. 12, 12 «; XLR

— spicula ...

9 ...

. . . XLIV, fig. 1 .

— strangulatum ...

8 ...

... XLIV, fig. 2.

MoNODONTA arata

102 ..

... XLV, fig. 19.

— comma

101 ..

XLV, figs. 24, 24 «.

— composita

23 ..

XLV, fig. 6.

— exigua

22 ...

... XLIV. fig. 29.

— Lycetti

22 ...

... XXXI, figs. 14, 14a.

— sparsistriata ...

22 ...

... XLV, fig. 9.

— tegulata

102 ...

... XLV, figs. 17, 18.

— Waltoni

101 ...

... XLV, figs. 31, 31a, 6.

Natica alta

97 ...

... XLV, figs. 22, 22 a.

— arata

97 ...

... XLV, fig. 2.

— Hulliana

13 ...

XLI, figs. 2, 2 a.

— insignis

97 ..

XLV, fig. 21.

— te.xata

96 ...

XLV, figs. 30, 30 a.

Nerin^ia granulata

10 ...

... XXXI, figs. 12, 12 a.

Nerita clavatula

98 ...

... XLV, fig. 3.

— iuvoluta

20 ...

... XXXI, fig. 15.

Nekitopsis Archiaci

21 ...

... XXXI, figs. 7, 7a.

Onustus Burtouensis

... 103 ...

.. XLV, figs. 7, 7 a, i.

Phasianella variata

... 104 ...

. . . XLV, figs. 28, 28 a, b.

Pleurotomaeia Bathonica

... 105 ...

... XLV, fig. 10.

— Burtonensis

105 ...

.. XLV, figs. 8, 8 a. 6.

— granulata . . .

24 ...

... XXXI, figs. 8, 8 a.

— recondita . , .

... 106 ...

... XLV, fig. 7.

PcRPUEOiDEA insignis

6 ...

.. XXXI, figs. 2, 2 a.

RissoA? exigua

9 ...

... XLIV, fig. 11.

RissoiNA Milleri

18 ...

... XLIV, fig. 10.

— subulata

98 ...

... XLI, fig. 9.

— tumidula

98 ...

... XLIV, fig. 13.

INDEX.

12^

RissoiKA Witchelli ...
Solarium Bathonicutn

— Waltoni

— turbiniforrais
Trochus Burtonensis

— Guisei

— • strigosus ...
Turbo Burtonensis ...

— depauperatus

— subtexata
EuLiMA ? laevigata ...

PAGE

TABLE

18 ...

... XLIV, fig. 12.

23 ..

.. XLV, fig. 27.

104 ...

... XLV, figs. 2G, 26 a, i, f

104 ...

... XLV, figs. 23, 23 a, 6.

99 ...

... XLV, fig. 16.

21 ...

... XLV. fig. 14.

29 ...

... XLV, fig. 12.

100 ...

... XLV, fig. 15.

99 ...

... XLV, fig. 13.

100 ...

XLI, figs. 15, 15 a.

13 ...

... XXXI, fig. 3.

BIYALYIA.

Anatina siliqua

83

XXXV, fig. 15.

.\rca (cucullaea) clathrata 44

XXXIX, figs. 4, 4 «.

— coralliua

43

XXXIX, fig. 3.

Astarte A}'tonensis

7S

XL, fig. 13.

— Bathonica

76

XL, figs. 23, 23 a.

— flexicostata

79

XL, fig. 26.

— fimbriata ..

77

XL, figs. 34, 34 a.

— Hilpertouensis 78

XXXVI, fig. 10.

— ignota

77

XL, fig. 10.

— Leckenbyi

74

XLII, fig. 3.

— orbicularis

73

XL, fig. 33.

— politula

73

XXXV, fig. 16.

— Pontonis ..

75

XL, fig. 31.

— robusta

74

XXXV, fig. 6, 6 a.

— rustica

76

XXXV, fig. 5 ; XL, figs. 8, 8 a.

— imgulata . .

72

XXXV, fig. 20.

AvicuLA clathrata ..

36

XL, figs. 7, 7 a, h-

— subcostata

36

XL, fig. 24.

Cardium cognatum

54

XXXVI, tig,s. 3, 3 «, 2 4.

— incertum ..

53

XXXV, figs. 14, 14 a.

— globosum.

114

XXXVIII, figs. 2, 2 «, 6.

— liiigulatum

53

XXXIII, figs. 2, 2« ; XXXV, figs

— Witchelli

55

XL, fig. 36.

CoRBis elliptica

60

XXXV, fig. I.

— Neptuni

59

XXXV, fig. 19.

— rotunda

60

XL, fig. 17.

CoRBULA Agatha

65

XL, fig. 28.

— attenuata ..

62

XXXVII, figs. 6, 6 «.

— HuUiana ..

64

XXXVII, fig. 5.

— Islipensis ..

63

XXXVII, fig. 7.

1 a.

128

INDEX.

PAGE

CoRBULA involuta

63

CoRBicELLA subangulata ...

70

— subeequilatera...

69

Cypricabdia caudata

55

Cypeina bella

71

— Dayidsoni

71

— Islipensis ,

70

Gervillia bicostata

... Ill

— Islipensis

37

— ornata

111

— tortuosa (var.) ...

37

— Waltoni

110

Gresslya peregrina

79

Gryph^a minuta

30

Harp AX Waltoni

101

HiNNiTES gradus

35

HoMOMYA gibbosa

88

— crassiuscula

89

Inoceramus quadratus

38

IsocARDiA tenera

57

— minima ..

56

— nitida .

57

IsoARCA Scarburgensis

45

Leda Anglica

45

Lima Helvetica

41

— pectiniformis ..

39

— punctatilla

41

— rigid ula

42

LlTHODOMUs Porteri

114

LnciNA Beanii

59

— Burtonensis?

59

— striatula

58

Macrodon Hirsonensis, var. nig

osa 113

Modiola gibbosa

42

Myacites calceiformis

80

— modica

83

— recurvum . .

81

— sinistra

82

Ndcula Menkei

44

Opis Leckenbyi

61

— Luciensis

62

— pulchella

61

OsTREA Wiltonensis

... 108

— (Exogyra) lingulata

108

Pecten anisopleunis

32

— articulatus . .

34

— Griesbachi .

37

TABLE

XXXVII, figs. 4,4 a.
XL, fig. 9.

XXXV, fig. 12.

XXXVI, figs. 8, 8 a.
XL, figs. 15, 15 a.
XXXVI, figs. 6, 6 a.

XXXV, fig. 13.
XL, fig. 21.

XXXVI, fig. 7.
XL, fig. 29.
XL, fig. 25.
XXXII, figs. 4, 4 a, b.
XXXVI, figs. 2, 2 o, 2 b.
XL, fig. 12.

XXXII, figs. \,\a,b.

XXXIII, figs. 10, 10 a.

XLIII, figs. 2, 2a; Part II, XII, fig. 14.
XLIII, figs. 5, 5 a.

XXXVIII, figs. 1, la, 16.
XXXVIII, figs. 5, 5 a, b.
XXXVI, figs. 1, 1 n.

XXXVIII, figs. 6, 6 a, 6 6, 6 c.

XXXIX, figs. 5, 5 a.
XXXIX, fig. 7.
XXXIII, figs. 8,8 a.
XXXVI, fig. 1.

XL, fig. 32.
XXXIII, figs. 7, 7 a.
XL, fig. 9.
XXXVIII, fig. 3.
XL, figs. 20, 20 a, b.

XXXVIII, fig. 7.
XXXVI. fig. 9.

XXXIII, figs. 11, 11 rt.
XLII, figs. 1,1a.
XLIII, figs. 1, 1 n.

XXXVI, figs. 4, 4 a.
XXXV, figs. 17, 17 a.

XXXIX, fig. 2.

XXXVII, figs. 9, 9 a.
XL, figs. 19, 19 a.
Part II, VI, fig. 3.

XXXIV, figs. 1, 1 «.

XXXII, figs. 2, 2 a, b.

XXXIII, figs. .^), 3 a.
XXXIII, fig. 12.
XXXIII, figs. 6, 6 a.

INDEX.

!2U

PAGE

PiiCTEX insequicostatus

3-2

— Michelensis

34 .

— rigidus

31 .

— Rushdonensis

33

— subspinosus

113

— Wollastouensis

33 .

Peena foliacea

38

— mytiloides ...

... 112

— obliqiia

112

Pholadojiya deltoidea

86

— lyrata

87

— ovulum

84

— Pbillipsi

86

Placunopsis semistriatus .

30

SowEEBYA triangularis

66

— Woodward!

67 .

Tancredia gibbosa

68

— niactraeoides

68 .

— similis ...

68

Theacia amygdaloidea

80 .

Trigonia arata

52

— Bathonica

52

— Cassiope

49 .

— clythia

48,51 .

— compta

50 .

— elongata

48 .

— Scarburgensis

48 .

— tripartita

51

— tuberculosa

47 .

TABLE

XXXIII, figs. 1, Iff.

XXXIII, fig. 3.

XL, fig. 16.

XXXIII, figs. 4, 4 a, b, a.

XL, fig. 14.

XXXIII, figs. 2, 2ff, h, c.
XXXVII, figs. 3, 3 a.

XXXII, fig. 3.

XXXIV, figs. 22, '22 II.
XLII, figs. 4, 4 a.
XLIII, figs. 3, 3 a.

XXXV, figs. 18, IS a.
XLII, figs. 2, 2 a.

XXXIII, figs. 9, 9 a.
XXXV, figs. 3, 3 a, b.
XL, figs. 27, 27 a, 6, c.
XXXV, fig. 7 ; XXXVI, fig. 11.
XXXV, fig. 4.

XXXV, fig. 9.

XLIII, fig. 4.

XL, fig. 2.

XL, fig. 3.

XXXVII, fig. 10.

XXXVII, fig. 2 ; XL, figs. 5, 5 a.

XL, fig. 1.

XXXIX, figs. 6, 6 a.

XXXVII, fig. 1.

XL, fig. 4.

XL, fig. 6.

LONDOK : PEIKTBD BT J. E. ADLAKD, BABTHOLOMEW CLOSE, E.C.

TAB. XXXI.

Fig.

1. Ammonites Bullatus, Z)'0/-3. Reduced one half. Great Oolite (page 3).

2. 2 a. Purpuroidea insignis, Lye. An aged shell, in which the tubercles have

disappeared upon the anterior portion of the
last volution. Great Oolite (page 6).

3. Eulima? laevigata, Li/c. Cornbrash (page 18).

4. Fibula variata, Zyc. Specimen with the anterior extremity of the aperture

approaching to Cerithium.
4 a. „ „ With the anterior part of the aperture approaching to

Tun-itella. From the Great Oolite of Kirklinorton,
Oxon. (page 16).

5. „ euWmoidiG?,, Whiteaves. From the Great Oolite of Stonesfield (page 17).

6. Amberleya armigera, Lt/c. Cornbrash (page 20).

7. Neritopsis Archiaci, D'Arc/dac, sp. Cornbrash (page 21).

7 a. „ „ A portion of the surface magnified (page

21).

8. Pleurotomaria granidata, Sow., sp. Cornbrash (page 24).

8 a. „ „ A portion of the surface magnified, in-

cluding the fascia of the sinus.

9. Acteonina canahculata, L^c. Great Oolite of Kirklington, Oxon. (page 27).

9 a. „ „ The spire enlarged.

10. Chemnitzia vittata, F/iil., sp. Cornbrash (page 14).

11. Dentalium entaloides, Z^esA Cornbrash (page 28).

1 1 «. „ „ A portion of the posterior part of the shell

enlarged, to exhibit the oblique striations.

II a. „ „ Enlarged view of the anterior portion of the shell,

in which the striations have disappeared.

12. Nerinsea granulata, P/iiL, sp. Cornbrash (page 10).

12. „ „ A portion of the spire enlarged.

13. 13 a. Acteonina Scarbiu-gensis. Cornbrash (page 28).

14. Monodonta Lycetti, TFIdteaves. Bradfordian beds of Ishp, Oxon. (page 22).

15. Nerita involuta, Li/c. Great Oolite, Kirklington (page 20).

IG. Acteonina Luidii, ZotW., sp. Forest Marble, Kidlington, Oxon. A small speci-

men, with short spire (page 27). See also
Tab. LXI, figs. 18 a, b, c.

^h. XXXI.

WWestm^i

TAB. XXXII.

Fig.

1. llarpax Waltoni, Lye. The attached valve. Forest Marble (page 110).

1 a. „ „ Interior of the left valve.

1 b. „ „ Interior of the right valve.

2. Ostrea (Exogyra) lingiilata, Walton, MSS. Forest Marble (page 108).

2 a. „ „ „ Interior of the convex valve.
2 h. „ „ „ Interior of the ilat valve.

3. Perna raytiloides, Lam. Forest Marble (page 112).

4. 4 a, 4 b. GerviUia Waltoni, Lye. Forest IMarble (page 110).

Ge,o, West lith ad oat

WWostL

TAB. XXXIII.

Pig.

1. Pecten inaequicostatus, Phil. Left valve. Cornbrash (page 32).

1 n- „ „ Right valve.

2. Pecten Wollastonensis, Lye. Great Oolite (page 33). Right valve.

2 3. „ „ Magnified surface of the right valve.
2 a. „ „ Left valve.

2 c. „ „ Magnified surface of the left valve.

3. „ Michelensis, Buv. Cornbrash (page 34).

4. ,, Riishdenensis, Zyc. Cornbrash (page 33).

4 a. „ „ Magnified portion of the right valve.

4 5. „ „ Left valve.

4 c. „ „ I\Iagnified portion of the left valve.

5. „ anisopleurus, Buv. Right valve. Cornbrash (page 34).

5 a. „ „ Left valve.

6. „ Griosbachi, Zyc. Left valve. Great Oolite (page 37).

6 a. „ „ Portion of the surface magnified.

7. Lima rigidula, P/iil., sp. Cornbrash (page 42).

7 a. „ „ Portion of the surface magnified.

8. „ Helvetica, Oppel. Cornbrash (page 41).

8 a. ,, ,, Portion of the surface magnified.

9. Placunopsis semistriatns, Bean, sp. Cornbrash (page 30).

9 a. „ „ Portion magnified.

10. Hinnites gradus, Bean, sp. Cornbrash (page 35).
10 a. „ „ Portion magnified.

11. 11 a. Modiola gibbosa, Sow. Cornbrash (page 42).

12. Pecten articulatus, ScMoth. Cornbrash (page 34).

PLXKXlll.

itjo iWesi. hiJi adnal.

W.Wesi- imp.

TAB. XXXIV.

Fig.

1. Ostrea Wiltoiiensis, Li/c. Forest Marble.

1 a. „ „ A monstrosity of the same species.

2. -2 a. Perna obliqua, Walton, MSS. Forest Marble.

3. Ostrea costata, Soic. Great Oolite. Also Part II, Tab. I, fig. 5, page 3.

PL XXXI \:

iV.iWrel llll, ailiial

WWfSt illl|'-

TAB. XXXV.

Fig.

1. Corbis elliptica, Whiteaves, MSS. Forest Marble. Slightly enlarged (page GO).

2. 2 a. Cardium subtrigonum, Mor. and Lj/c. Great Oolite. See also Part II, Tab. VII,

fig. 3, page 64.

3. Sowerbya triangularis, PJdl., sp. Cornbrash (page 66).

3 a. „ „ Portion of the surface magnified.

3 6. „ „ Hinge of the right valve magnified.

4. Tancredia mactrseoides, Whiteaves, MSS. Great Oolite (page 68).

5* Astarte mstica, Walton, MSS. Great Oolite and Forest Marble (page 76).

Also Tab. XL, fig. 8.

6. ,, robusta, Li/c. Cornbrash (page 74).

6 a. „ „ A portion of the surface magnified, exhibiting the inter-

stitial striations.

7. Tancredia gibbosa, Lye. Great Oolite (page 68).

8. Nseara Ibbetsoni, Mor. Slightly enlarged. Great Oolite. See also Part 11,

Tab. XII, fig. y.
8 a. „ ,, A portion of the surface magnified.

9. Tancredia similis, Whiteaiies, MSS. Great Oolite (page 68).

10. Isocardia? nitida, PJdl. Cornbrash. See also Tab. XXXVIII, figs. 6, 6 a.

10 a. „ ,, A portion of the surface magnified.

11. 11 «. Cardium lingulatum, Li/c. An oblique specimen. Also Tub. XL, fig. 22,

page 53.

12. Corbicella subaequilatera, Li/c. Cornbrash (page 69).

13. Cyprina Islipensis, Lye. Great Oolite. Our figure is scarcely sufficiently

lengthened and inequilateral (page 70).

14. 14 a. Cardium incertum, Phil. Great Oolite (page 53).

15. Anatina (Cercomya) siliqua, Jy, Cornbrash (page 83).

16. Astarte politula, Bean. Cornbrash (page 73).

17. 17 a. Myacites sinistra, ^y., sp. Cornbrash. A breadth of two lines would require to

be added to the posterior side to render the
outline perfect (page 82).

11 b. ,, ,, A portion of the surface magnified.

18. 18 a. Pholadomya ovulum, Aff. Cornbrash (page 84).

19. Corbis Neptuni, Lj/c. Great Oolite (page 59).

20. Astarte ungidata, A. lurida, PhiL, non Sow. Cornbrash (page 72).

PLXXXV.

Geo W«ut. Kth «ul nut..

TAB. XXXVI.

Fig.

1. 1 rt. Isocardia minima, Phil. Cornbrash. Specimen with the posterior angle

more strongly defined than usual (page 56).

2. 2 a, 2 h. Gresslya peregrina, Fhih, sp. Cornbrash. Three varieties. See also Part II,

Tab. XV, fig. 8, page 79.

3. Cardium cognatura, Phil. Cornbrash (page 54).

4. Myacites recurvura, Phil., sp. Cornbrash (page 81).

5. Ceromya concentrica, Soic, sp. Great Oolite. See also Part II, Tab. X, fig. 3.

6. f)r/. Cyprina Davidsoni, Lye. Forest Marble (page 71).

7. Gervillia ornata, Zyr. Great Oolite. Enlarged (page 111).

8. Cypricardia caudata, Lijc. Great Oolite and Forest Marble (page 55).
8 a. „ „ A portion of the surface magnified.

9. Macrodon Hirsonensis, Arch., var. rugosa. Forest Marble (page 113).

10. Astarte Ililpertonensis, Lye. Forest Marble (page 78).

11. Tancredia gibbosa. Lye. Forest Marble. See also Tab. XXXV, fig. 7.

mxKxvi.

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W.West iiigj.

TAB. XXXVII.

Fig.

1. Trigonia Scarburgeiisis, Lye. Cornbrash (page 48).

2. „ Clythia, lyOrh. Great Oolite (page 48). See also Tab. XL, fig. .5.

3. 3 r/. Perna foliacea, Lye. Great Oolite (page 38).

4. 4 «. Corbula involuta, J/?<;«/. Enlarged. Great Oolite (page 63).

5. „ Hulliana, Mor. Enlarged. Forest Marble (page 64).
G, a. „ attenuata, Zyc. Enlarged. Great Oolite (page 62).

7. „ Islipensis, Zye. Enlarged. Great Oolite (page 63).

8. ,, Buckmani, Buclc., sp. Great Oolite. Also Part II, Tab. IX, fig. 6,

page 97.

9. 9 a. Opis Leckenbyi, Wriyht. Cornbrash (page 61).
10. Trigonia Cassiope, D'Orb. Cornbrash (page 49).

n.jaxxni.

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'-^^i^^^.

S«*i

W Weg imp

TAB. XXXVIII.

Fig.

1. Inoceramus quadratus, Sow., sp. An aged example (page 38).

1 a, „ „ A smaller specimen, partially denuded of the

test, and exhibiting concentric and radiat-
ing striations upon the surface of the cast.

1 i5. ,, „ Interior of the right or flat valve.

2. 2 d. Cardium globosum, Bean. Cornbrash. The original specimen figured by .Mr.

Bean (page 114).

2 a. „ „ Portion of the surface magnified.

3. Lucina ? Beanii, i?r«//, sp. Cornbrash (page 59).

4. „ despecta, P/iil. Cornbrash (Part II, p. G9).

4 a. „ „ Portion of the surface magnified.

5. 5 a. Isocardia tenera, Sow. Cornbrash. Part II, p. 57.

6. 0«. „ nitida, P////. Cornbrash (page 57). Also Tab. XXXV, fig. 10.
6 i. „ „ Portion of the surface magnified.

7. Lueina striatula, Bkv. Cornbrash (page 58).

PLJxjxvm.

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Geo. West iiUi

W WcsL L

TAB. XXXIX.

Fig.

1. Lima pectinifomiis, Schloth. A large specimen, with tubular spines (page 39).

2. Nucula Menkei, Boem. Great Oolite (page 44). See also Tab. XL, fig. 12.

3. CucuUaea corallina, Li/c. Cornbrash (page 43).

4. 4 a. „ clathrata. Led: Cornbrash (page 44).

5. Isoarca Scarburgensis, L^c. Cornbrash (page 45).

5 a. „ „ Portion of the surface magnified.

6. 6 a. Trigonia elongata, Soiv. Cornbrash (page 46).

7. Leda Anglica, D'Orb. Cornbrash (page 45).

Ph.XXXlJL.

uev: West-litii

W Wfisi, imp.

TAB. XL.

Fig.

1. Trigonia compta, iyc. Colly weston Slate (page 50).

2. „ arata, Lye. Forest Marble (page 52).

3. ,, Bathonica, Lye. Great Oolite (page 52.)

4. „ tripartita, Forbes. Cornbrasli (page 51.)

5. „ Clythia, D'Ori. Great Oolite. A specimen of advanced growth.
5 a. ,, ,, An adult specimen (pages 48 and 51).

6. ,, tuberculosa, Lye. Great Oolite. Magnified (page 47).

7. Avicula clatlirata, Lye. The smaller valve, magnified. Great Oolite.
7«. „ ,, The larger valve, niaguified (page 36).

7 6. „ ,, Portion of the surface magnified.

8. 8 a. Astarte rastica, Walton, MSS. Great Oolite and Forest Marble (page 76).

9. Corbicella subangulata. Lye. Forest Marble (page 70).

10. Astarte ignota, Lye. Forest Marble (page 77).

11. Pecten personatus, Gold/., var. Great Oolite. Magnified. Part II, page 11.
\\ a. „ „ Another variety, magnified.

12. Nucula Menkei, Roem., var. Also Tab. XXXIX, fig. 2, page 44.

13. Astarte Aytoneusis, Bean. Great Oolite (page 78).

14. Pecten subspinosus, Schloth. Forest Marble (page 113).

15. Cyprina bella, Walton, MSS. Forest Marble (page 71).
15 a. „ ,, A shorter specimen.

16. Pecten rigidus, iSow. Great Oolite (page 31).

17. Corbis rotunda, iyc. Forest Marble (page 60).

18. I8a. Cardium Buckmani. Young specimen. Forest Marble. Part II, page 64.
18 5. ,, ,, The striated surface magnified.

19. 19 a. Opis Luciensis, D'Oib. Great Oohte (page C2).

20. 20 a. Lucina? Burtonensis, Lye. Forest Marble (page 59).

21. Gervillia bicostata, Lye. Great Oolite.

22. Cardium lingulatum. Lye. Also Tab. XXXV, fig. 11, page 53.

23. 23 a. Astarte Bathonica, Lye. Great Oolite (page 76).

24. Avicula subcostata, Roem. Great Oolite (pages 36, 111).

25. Gervillia tortuosa. Sow., var, Corubrash (page 37).

26. Astarte flexicostata. Lye. Great Oolite (page 79).

27. 27 a. Sowerbya Woodward!, Lye. Left valve. Great Oolite (page 67).
276,27 c. „ „ Right valve.

28. 28 a. Corbula Agatha, VOrb. Forest Marble. Magnified (page 65).

29. Lithodomus Porteri, Xyc. Forest Marble. Magnified (page 114).

30. Gryphsea minuta, Sow. Great Oolite. Magnified (page 30).

31. Astarte Pontonis, Lye. Great Oolite. Magnified (page 75).

32. Lima punctatilla, iyc. Great Oolite. Magnified (page 41).

33. Astarte orbicularis, Sow. Great Oolite. Magnified (page 73).
34,34 a. „ fimbriata, ^a/^on, MSS. Forest Marble (page 77).

35. Gervillia Islipensis, Lye. Great Oolite (page 37).

36. Cardium Witchelli, Lye. Great Oolite. Magnified (page 55).

n.XL.

2S<^

Geo West bth.aduai.

W. West imp.

TAB. XLI.

Fig.

1. Amberleya capitanea, Goldf., sp. Forest Marble (page 95).

2. 2 a. Natica HuUiana, Lye. Great Oolite (page 13).

3. Amberleya nodosa. See also Part I, Tab. V, fig. 19.

4. Acteonina olivseformis. Great Oolite and Forest Marble. See also Part I,

Tab. VIII, fig. 14. and fig. 12*.
4 a. „ „ A specimen of more advanced growth, with the spire

more produced.

5. „ Kirklingtonensis, Zyc. Great Oolite (page 26).

6. „ brevis, Zj/c. See also CyVindrltis? brevis, Part I, Tab. VIII,

fig. 13, page 26.

7. 7 a. Nerita Buvignieri. Examples of two stages of growth. See also Stomatia

Biiviynieri, Part I, Tab. IX, fig. 32. The specimens
now figured are from the Forest Marble of Laycock.

8. 8 a. Ammonites discus, Sow. Forest Marble. Slightly reduced (page 4).

9. Rissoina subulata. Lye. Great Oolite. Enlarged (page 98).

10. Amberleya monilifera, Li/e. Forest Marble. Enlarged (page 95).

11. Cerithium costigerum, Piefte. Variety with flattened volutions and oblique

costse (page 92).
\\a. „ „ A portion of the surface enlarged.

11 ^. „ „ Specimen with shorter, more inflated volutions,

and perpendicular costae.
lie. „ „ A portion of the surface enlarged.

12. Kilvertia pulchra. Lye. Great Oohte and Forest Marble. For the form of the

aperture see Tab. XLIV, fig. 4, pages 10 and 94.

13. „ „ A portion of the surface enlarged.

13. Alaria myums, Desl. See also Alaria laviyata. Part I, Tab. Ill, fig. 3.

14. Amberleya tricincta, Lye. Forest Marble (page 96).

15. Tiu-bo subtexatus. Lye. Forest Marble.

16. Cerithium? Waltoni, Zj'c. Forest jMarble (page 92).

17. ,, hemicinctum, Lye. Forest Marble. Enlarged (page 91).

18. 18 a. Acteonina Luidii, Mor. An adult specimen, with the spire moderately elevated.

Forest Marble. See also Tab. XXXI, fig. 16,

page 27.
18 5. „ „ A specimen with the spire elevated.

18 e. „ „ Specimen with the spire elevated and the last whorl

unusually lengthened.

, f-^ ''^ -f? 11°-

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Geo.\fest]ilii

W. West imp.

TAB. XLII.

Fig.

1, la. Myacites calceiformis, P/iiL, sp. Cornbrasb. Specimen with the test preserved

(page 80).

2, 2 a. Pholadomya Phillipsi, 3Ior. Cornbrash (page 85).

3, Astarte Leckenbyi, Wright. Cornbrash (page 74).

4, 4«, Pholadomya deltoidea, /Sow. Forest Marble (page 86).

Ph. XT J J

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— ._..c-;^,^is;i

J:-.

;-;sj

/a/

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^

;i ^^

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Geo West Ml

WWestinj).

TAB. XLIII.

Fig.

1, la. Myacites modica, Bean, sp. Cornbrash (page S3).

2, 2 /7. Homomya gibbosa, Sow., sp. (Page 88.)

3, 3 ff. Pholadoiuya lyrata, <S'o?o. Cornbrash (page 87).

4, Thracia amygdaloidea, Lj/c. Great Oolite (page SO).

5, 5 a. Homomya crassiuscula. An adult specimen, with the test preserved. Part II,

page 112; Supplement, page 89.

Geo West Ml

WTWest in5>

TAB. XLIV.i

Fig.

1. Kilvertia spicula, Lijc. Great Oolite. Enlarged (page 9).

2. „ strangulata, U Arch. Great Oolite. For another variety see Part I,

Tab. IX, fig. 18.

3. Cerithium buliinoides, T)esl. Great Oolite. Enlarged (page 7).

4. Kilvertia pulcbra. Great Oolite. Enlarged. See also Tab. XLI, fig. 12,

page 10.
.5. „ formosa, Zyc. Great Oolite. Enlarged (page 95).

6. Cerithium undnlatum, Bed. Great Oolite. Enlarged (page 8).

7. „ Witchelli, Lye. Great Oolite. Enlarged (page 10).

8. Chenniitzia constricta, Lye. Great Oolite. Enlarged. Printed Kilvertia by

mistake at page 15.

9. Cerithium compositura, Lye. Great Oolite. Enlarged (page 9).

10. Rissoina Milleri, Lye. Great Oolite. Enlarged (page 18).

11. Rissoa? exigua, Lye. Great Oolite. Enlarged (page 9).

12. Rissoina WilcheUi. Great Oolite. Enlarged (page IS).

18. Rissoina? tumidula, Zyc. Great Oolite. Enlarged (page 98).

14. Cylindrites exigua. Lye. Great Oolite. Enlarged (page 24).

15. Acteonina fasciata, Lye. Forest Marble. Enlarged (page 107).

16. Acteon Bathonicum, Lye. Great Oolite. Enlarged (page 25).

17. Brachytrema buccinoidea, Lye. Great Oolite. Enlarged (page 5).

18. Acteonina scalaris, Lye. A small specimen from the Great Oolite (page 28).

19. Cerithium? Bathonicum, Lye. Great Oolite. Enlarged (page 6).

20. „ multiforme, Piette. Great Oolite. Enlarged (page 7).

21. „ ? neglectum, Lye. Great Oolite. Enlarged (page 92).

22. Ceritella Morrisea, Orthostoma, Biw. See also Part I, Tab. IX, fig. 14.

23. Cerithium exscalptum, Lye. Great Oolite. Enlarged (page 93).

24. „ poculum, Lye. Great Oolite. Enlarged (page 93).

25. Ceritella Lycettea, Orthostoma, Buv. See also Part I, Tab. IX, fig. 7.

26. 26<5f. Cylindrites tm-riculatus. Lye. Great Oolite. Enlarged (fig. 25).

27. Brachytrema varicosa. Lye. Great Oolite. Enlarged (page 5).

28. Acteon phasianoides. Lye. Great Oolite. Enlarged (page 26).

29. Monodonta exigua, Lye. Great Oolite. Enlarged (page 22).

^ All the fossils upon this Tab., excepting No. 15, were obtained by crushing slielly portions of the
Great Oolite.

pi.XLir.

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21 lA

Ge "West, lilh . ajcLnal, .

WWesl inip

TAB. XLV.

Fig.

1. Monodonta Lyellii, D'Arch., sp. Young shell. For the aJult couditiou see Part I, Tab. XI,

fig. 4.

2. Natica arata, Lijc. Great Oolite. Enlarged (page 97).

3. Nerita clavatula, Lye. Great Oolite. Enlarged (page 98).

4. Ceritella fusiformis, Zyc. Great Oolite. Enlarged (page 12).

5. ,, minutissima, Lye. Great Oolite. Enlarged (page 11).

6. Monodonta composita, Li/c. Great Oolite. Enlarged (page 23).

7. Pleurotomaria recondita, Lye. Great Oolite. Enlarged (page 106).

8. ,, Burtonensis, Zryc. Forest Marble (page 105).
8 a. ,, „ The base.

8 b. „ ,, Portion of the surface magnified.

9. Monodonta sparsistriata, Zyc. Great Oolite. Magnified (page 22).

10. Pleurotomaria Bathouica, Z-yc. Great Oolite. Magnified (page 10.">).

11. lie. Onustus Burtonensis, Lye. Forest Marble. Slightly enlarged (page 103).

12. Trochus strigosus, Li/c. Cornbrash (page 29).

13. Turbo depauperatus, Lye. Forest Marble. See also Pleurotomaria pagodus, Part I, Tab. X,

fig. 9.

14. Trochus Guisei, Lye. Great Oolite. Magnified (page 21).

15. Turbo Burtonensis, Lye. Forest Marble (page 100).

16. Trochus Burtonensis, Lye. Forest Marble (page 99).

17. Monodonta tegulata, iyc. Forest Marble. Specimen with fine striations (page 102).

18. „ ,, Forest Marble. Enlarged.

19. „ arata, Zyc. Forest Marble. Enlarged (page 102).

20. ,, „ Variety with the encircling lines more distantly arranged.

21. Natica insignis. Lye. Great Oolite. Enlarged (page 97).

22. ,, (Euspira) alta, Lye. Forest Marble (page 97).

23. Solarium turbiniformis. Lye. Forest Marble (page 104).

23 a. „ „ A portion of the surface enlarged.

23 6. ,, „ The lower surface.

24. 24 a. Monodonta comma. Lye. Forest Marble (page 101).

24 b. „ „ A portion of the surface enlarged.

25. Acteonina Wiltonensis, Lye. Forest ilarble (page 107).

26. 26 a. Solarium Waltoni, Lye. Forest Marble. Upper surface and profile (page 104).

26 b, c. ,, ,, Forest Marble. Lower surface.

27. 27 o. Solarium Bathonicum, Lye. Great Oolite. The upper surface and profile (page 23).

27 b, 27 e. ,, ,, The lower surface of a smaller specimen.
27 rf. „ ,, A portion of the upper surface magnified.
28,28 a, 28 4. Phasianella variafa. Lye. Page 104.

29, Acteonina Suessea, Lye. Forest Marble (page 107).

30, 30 a. Natica texata, Lye. Forest Marble (page 96).

31, 31 a. Monodonta Waltoni, Lye. Forest I\Iaible. Enlarged (page 101).

31 b. „ A portion of the striated surface magnified.

Pl.XLV.

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