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MONOGRAPH OF THE DEVONIAN FAUNA OF THE SOUTH OF
ENGLAND.

ORDER OF BINDING AND DATES OF PUBLICATION OF VOL. II.

PAGES. PLATES. es make | PUBLISHED.
General Title-page and Index _ 1907 | December, 1907
1—56 I—V | 1891 | February, 1892
57—88 | Vil xX 1892 November, 1892
89—160 Ke | 1893 | December, 1893
161—212 XVITI—XXIV | 1895 October, 1895
213, 214 = | 1907 December, 1907

A MONOGRAPH

OF THE

DEVONIAN FAUNA

OF THE

SOUTH OF ENGLAND.

BY

G. F. WHIDBORNE, M.A., F.G:S.

VOL. II.

PER: EAUNA OF; THE DIMESTONES

OF

LUMMATON, WOLBOROUGH, CHIRCOMBE BRIDGE, AND CHUDLEIGH

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY.

1892—1907.

PRINTED BY ADLARD AND SON, LONDON AND DORKING.

PALAONTOGRAPHICAL SOCLETY.

INSTITUTED MDCCCXLVIL.

VOLUME FOR 1891.

MDCCCXCII,

“a
a

Ses

A MONOGRAPH

OF THE

DEVONIAN FAUNA

OF THE

SOUTH OF ENGLAND.

BY

G. F. WHIDBORNE, M.A., F.GS.

Vou. L1.—Parr I.

THE FAUNA OF THE LIMESTONES

OF

LUMMATON, WOLBOROUGH, CHIRCOMBE BRIDGE, AND CHUDLEIGH.
(Continued.)

Paars 1—56; Prares I—V.

LONDON:
PRINTED FOR THE PALZONTOGRAPHICAL SOCIETY.
1892.

PRINTED BY
ADLARD AND SON, BARTHOLOMEW CLOSE.

A MONOGRAPH

OF THE

DEVONIAN FAUNA

OF THE

SOUTH OF ENGLAND.

VOL. II.

Crass.—-LAMELLIBRANCHIATA, Blainville, 1814.

Prxecypopa, Coldfuss, 1820.

In describing the Bivalves from these rocks we are met by the difficulty that
the interior and the hinge are hardly ever exposed, and that consequently their
systematic position has generally to be inferred from analogy to other species
from more favoured localities. Added to this, in so rough a matrix the margins of
single valves have been peculiarly liable to injury in fossilization, or to destruction
in the attempt to develop them. This necessarily gives rise to a large amount of
doubt in the determination of some of the forms described.

As regards the number of species, this class is fairly represented both at
Lummaton and Wolborough, but as a rule individual specimens are extremely
rare. Four or five species, however (e.g. Conocardium clathratum, Cypricardinia
scalaris, Rutotia elliptica, and one or two Pterines), may be regarded as common
shells, although in no instance do they at all approach the Brachiopods in
abundance.

From Chudleigh we have only two species; but one of these, Mecynodon colwm-

VOL. Il. 1

2 DEVONIAN FAUNA.

binus, is a remarkably beautiful form, and its specimens are strangely different
from most Devonian fossils in the excellency of their preservation. It is, in fact,
fortunate that their locality is absolutely certain, as otherwise our rocks would
never have been credited with producing fossils so delicately beautiful, perfect,
and free from matrix.

Phillips described only eight shells from Newton, Barton, or Bradley, and of two
of these I have been unable to find examples. The number of species is now raised
to about fifty-five. These are referred to the followimg genera :—Hdmondia (2),
Allorisma (1), Cypricardinia (4), Isocardia (1), Goniophora (1), Conocardium (7),
Megalodon (1), Mecynodon (2), Protoschizodus (1), Nucula (1), Parallelodon (1),
Modiolopsis (3), Hoplomytilus (1), Myalina (5), Gosseletia ? (1), Mytilarca (1),
Plethomytilus (1), Posidonomya (1), Rutotia (1), Pterinea (1), Actinopteria (9),
Leiopteria (1), Pterinopecten (3), Aviculopecten (2), Crenipecten (2), Lyrio-
pecten (1).

1. Orper.—SIPHONIDA, Fleming, 1828.
1. Sus-orper.—SINUPALLIATA, d’Orbigny, 1843.
I. Family.—Anatinion, Gray, 1840.
1. Genus.—Epmonpt1a, de Koninck, 1842.

Under this heading are included transversely oval, tumid, thin shells, with
edentulous hinges and narrow external ligaments. They extend from the Silurian
to the Permian.

1. Epmonpra canata, n. sp. Pl. I, fig. 4.

Description.—Right valve very long, narrow, ovoid, tumid. Umbo small,
rounded, incurved, turned forward, and situated nearly at the anterior extremity.
Escutcheon narrow, indefinite. Anterior margin small, short, convex. Inferior
margin gently convex. Posterior margin deeply and symmetrically convex. Dorsal
margin rather short and slightly convex. Contour of back very much rounded,
arching steeply above, below, and in front, obliquely flattened behind. Point of
greatest depth somewhat in front of centre. Surface covered by minute,

EDMONDIA. 3

indistinct, irregular, and unequal strive or growth-lines. Hinge invisible. Shell-
structure extremely thin.

Size of right valve-—Length 40 mm., breadth 20 mm., depth 8 mm.

Locality.—There is a specimen in Mr. Vicary’s Collection’ from Wolborough.

femarks.—The fossil here described is imperfect in front, and presents few
data for determining its position. A comparison, however, with the numerous
Carboniferous species of Hdmondia, described by de Koninck, shows that, as far as
can be judged from outward characters, it evidently belongs to that genus. Its
much greater length distinguishes it specifically from all of them except H. ? debilis,
de Koninck,’ H. ? prxlonga, de Koninck,’ L. elegantula, de Koninck,’ and H. ? angusta,
de Koninck ;* each of which differs from it by being much broader in front and
narrower behind.

2. HDMONDIA, sp.

Description.— Right valve long, ovoid, tumid, the length being to the height
as 3:2. Umbo apparently anterior, rounded, rather prominent. Area broad,
concave, indefinite. Anterior margin probably rather broad. Inferior margin
very slightly convex. Posterior margin roundly convex. Dorsal margin pro-
bably straight near the beak, and then becoming slightly oblique and convex.
Contour of back very much rounded, with steep sides except posteriorly. Surface
covered by fine, indistinct, irregular, and unequal striz or growth-lines. Hinge
invisible. Shell-structure extremely thin.

Size of right valve.—About 41 mm. in length, 28 mm. in breadth, and 10 in
depth.

Locality.—A. single defective specimen from Wolborough is in the Museum of
Practical Geology.

Remarks.—This specimen is very poor and fragmentary. At first I supposed
it to be a second example of HV. celata, but further examination makes me believe
that it is really distinct from that species. The chief difference lies in its general
shape, which is much less transverse, and considerably less tumid. While in the
former the length is double the height, in the present form their ratio is only
3:2, The umbo also seems less transverse, and the area broader, shallower, and
more diffuse behind. It is too defective to admit of being figured.

1 1885, de Koninck, ‘ Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. 5, p. 50, pl. vii, figs. 17, 18.
2 Ibid., p. 50, pl. vii, figs. 21, 22.

3 Thid., p. 45, pl. xi, figs. 17—19.

4 Tbid., p. 50, pl. xiii, figs. 6, 7.

4 DEVONIAN FAUNA.

2. Genus.—ALiorisma, King, 1844.

These shells are elongate, very thin, equivalve, edentulous, and very inequi-
lateral, with elongated ligamentary supports, and with concentrically plicate and
finely punctate surfaces. They range from the Devonian to the Pernian.

1. Attorisma DuBIuM, Whidborne, sp. PI. I, figs. 2, 2a, 3.
1889. Epmonp1a? puBia, Whidborne. Geol. Mag., Dec. 3, vol. vi, p. 79.

Description.—Left valve long, rather narrow, ovoid, slightly convex. Umbo
small, incurved, very anterior, turned forwards, oblique, depressed below the
greatest altitude. Lunule small, deep, undefined. Area narrow, concave, deep.
Anterior margin small, very convex. Inferior margin slightly oblique and
convex. Hinge-margin slightly convex. Shell-structure papyraceous. Surface
covered with numerous, very fine, sharp, regular, close, bifurcating growth-strie,
and (on the internal cast) with very low indistinct radiations.

Size of valve.—Breadth 34 mm., depth 14 mm.

Localities—An imperfect specimen from Wolborough is in Mr. Vicary’s
Collection, and a still more defective shell from Lummaton is in my Collection.

Remarks.—Mr. Vicary’s specimen has lost the posterior portion, and is
another of the many fossils from these localities which rather prove the existence
of a species than enable us to describe it.

It appears to come so near to Allorisma sulcatwm, Fleming, sp.,' as in all
probability to belong to the same genus, while it differs specifically in being
much less elongate, and in its ornament being finer. The radiations mentioned
above probably indicate the punctate lines which characterise this genus.
De Koninck’s genus Broekia’ also presents characters to which it approaches.

Affinities—From Hdmondia celata it differs by being much flatter and broader,
by having a differently shaped umbo, the posterior boundary-line of which is
much sharper and more defined, and overhangs the hinge-margin so as only to
leave room for a narrow condave area, and by showing signs of radiation.

1 1836, Phillips, ‘Geol. Yorks.,’ pt. 2, p. 209, pl. v, fig. 5; and 1884, Tryon, ‘Struct. Conch.,’
vol. iii, p. 148, pl. evii, fig. 4:4.
2 1885, de Koninck, ‘Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. 5, p. 19.

CYPRICARDINIA. 5

Il. Family.—Cypriniva, Gray, 1840.
1. Genuws.—Cyrricarpinia, Hall, 1859.

This appears to be a very well-marked genus, although its characters are only
partially known. It is very like Cypricardia, Lamarck, but thinner. It is in-
equivalve; its umbo is smal! and more or less anterior; it has a dorsal keel, and
is covered with concentric ridges and sometimes with finer radiating ornament.
It reaches from the Silurian to the Carboniferous.

The species of this genus seem for the most part to show a large amount of
individual variation, and hence it is not easy to define their limits, especially where
specimens come from different countries.

In our present localities it is represented by at least four species.

1. CypricarpInia scanaris, Phillips, sp. Pl. I, figs. 6—8.

1841. Moprota scanaris, Phillips. Pal. Foss., p. 187, pl. lx, fig. 62*.
? 1842. CypricarpIrEs INDENTA, Conrad. Journ. Acad. Nat. Sci. Philad., vol. viii,
p- 244, pl. xii, fig. 12.
? 1842. eS INFLATA, Conrad. Ibid., p. 246, pl. xv, fig. 2.
1849. Myrinus scatarts, d’Orbigny. Prodrome, vol. i, p. 82.
1850. Cypricarpia squaMIFrEeRA, F. A. Rémer. Beitr., pt. 1, p. 38, pl. vy,
figs. 4a, b.
1850. — ELonGATA, F. A. Romer. Beitr., pt. 1, pl. v, figs. 4a, b.
1851. Omatra scataris, de Ryckholt. Mélang. Pal., pt. 2, p. 74.
1853. CYPRICARDIA LAMELLOSA, Sandberger. Verst. Rhein. Nassau, p. 262,
pl. xxvii, figs. 13, 13 a—e.
1854, Moproza scanaris, Morris. Catal. Brit. Foss., p. 210.
1861. COYPRIcARDINIA LAMELLOSA, Hall. Pal. N. Y., vol. iii, p. 266, pl. xlixa,

fig. 1 a—e.

21870. Cypricarpinra InDENTA, Hall. Prelim. Notice Lamellibr., pt. 2, p. 88.

? 1874. — pisTincra, Billings. Paleozoic Fossils, vol. ii, pt. 1, p. 56,
figs. 26, 27.

? 1881. — Gratiosa, Barrande. Syst. Sil. Bohém., vol. vi, pt. 1,

pl. celvii, figs. 1, 1-14, Et. F.
1884. — LAMELLOSA, Clarke. Neues Jahrb. f. Min., Beil.-Band iii,

p. 380.

? 1885. — sQuaMiIreRA, Maurer. Abhand. Grossh. Hessisch. Geol.

Landes. Band i, pt. 2, p. 231,
pl. ix, figs. 830—33.

1885. —_— INDENTA, Hall. Pal. N. Y., vol. v, pt. 1, sect. 2, p. 485,
pl. Ixxix, ‘figs. 6—16, 23; and pl. xevi,
fig. 2.

1888. Moproza scauanis, Etheridge. Foss. Brit., vol. i Pal., p. 161,

6 DEVONIAN FAUNA.

1889. Cyrpricarpta Ne@Lecta, Whidborne. Geol. Mag., Dec. 3, vol. vi, p. 79.
1889. CyYPRICARDINIA @RATIOSA, Barrois. Faun. Cale. d’Erbray, p. 171, pl. xi,
figs. 10 a, b.

Description.—Shell small, convex, angulated, elongate, subquadrate. Umbones
small, flattened, compressed, sharp, curving forward, situate at the anterior
point. Hinge-line long, slightly convex behind the umbones and arching rapidly in
front of them, sunk below the superior margin, apparently with a lhgamental space
below the umbones, and with an external ligament behind them. Superior margin
slightly convex; about two-thirds the length of the shell. Lunule small, cordate,
concave, undefined. Escutcheon very large, bounded by the line running from
the back of the umbones to the postero-inferior point, within which it is first
slightly concave and then rises to form the hind wing. Anterior margin narrow,
convex. Inferior margin gently undulating, being concave in the centre and convex
in front and behind. Posterior margin straight, oblique. Infero-posterior point
produced, rounded. Contour of shell elevated and nearly flat on the back, and
rounding rapidly over the post-umbonal line. Hind wing large, triangular, flat.
Surface marked by about eighteen transverse, elevated, rounded cords, less than
their own width apart, very small on the umbo, and gradually increasing till
they become very large in the marginal portion; each cord following the
marginal contour, itself bemg small anteriorly, gradually increasing in size until it
has passed the post-umbonal keel, again becoming suddenly smaller, and then
continuing of a uniform and median size until it is truncated by the upper margin.

Size.—Length 11 mm., breadth 7 mm., depth 5 mm.

Locality.—Lummaton. There is a fine example of the double shell in the
Torquay Museum; twenty-one specimens, chiefly of single valves, are in my
Collection, and five in the Woodwardian Museum.

Remarks.—This distinct little shell is decidedly common at Lummaton, where
I have found very many examples, although the valves are very rarely in contact,
and it is almost impossible to extract them from the matrix so as to show the
hinge. ‘They vary somewhat in length, and in the expansion of the anterior side
beyond the umbo, but their peculiar large step-like ribs give them a very distinctive
appearance. Nevertheless it has been by no means easy to decide whether they
are to be referred to any of the species which Phillips has figured. After repeated
examinations, however, I feel confident that the only one that can be identical is
Modiola scalaris, the surface of which he describes as “ridged by about fifteen
elevated, narrow threads, . . . separated by wider flat spaces, in which are
fine striz parallel to the elevated threads.” This is not shown in his figure, and
certainly does not accurately describe the ornament of the Lummaton fossils. His
type specimen, however, as well as two others from Berry Pomeroy, is in the
Museum of Practical Geology; they are all crushed and defective, but evidently

CYPRICARDINIA. 7

belong to the genus Oypricardinia, and they resemble our fossils more nearly than
they do his figure. Most probably they would be exactly like them but for their
different state of fossilization. I have, therefore, no hesitation in identifying our
Lummaton shells with Phillips’s species.

On one of these Berry Pomeroy specimens, which is an external cast, a fine
oblique striation is visible, and in some lights this is seen to be crossed by other
striz, so as to form an imperfect trellis-work ornament. It seems to me most
probable that these markings are due to the epidermis.

Turning next to F. A. Romer, we find him describing under the name
Cypricardia squamifera, Phillips, a shell which seems indistinguishable from our
fossils. (On his plate he has given it the name C. elongata, apparently by a misprint.)
Sandberger on the other hand, points out that F. A. Rémer’s shell cannot belong
to that Yorkshire species, as the latter has radiating striz. He therefore renames
Roémer’s shell Cypricardia lamellosa, and figures three varieties of it. These have
rather larger anterior margins than most, but not all, of our specimens, and the ribs
of two of them are rather smaller and closer; but, if Sandberger is right in
supposing them all to belong to one species, our fossils certainly fall within its
limits, and therefore his name becomes a synonym. In the British Museum are
three specimens from the Devonian of Belgium, received from M. de Koninck,
and originally labelled by him Cypricardia elegans, but now labelled C. lamellosa,
which are certainly the same as ours.

I have a strong impression that C. distincta, Billings, from the Canadian
Devonian, is also identical, or at most only a Transatlantic variety. It is itself
very variable; and its only differences from the English shell are that it is much
larger (85 mm. instead of 11 mm.), and that the hinge-line is longer than usual.

The shell referred by Barrois to C. gratiosa, Barrande, is clearly the same, as it
only differs in being rather deeper posteriorly. Barrois remarks that the Bohemian
form exactly agrees with his own except in having a trellis-work ornamentation,
which he supposes to be worn off in his specimen. From our shells the only
other distinctions I can see in Barrande’s species are that the ridges are rather
fewer, and the posterior part rather deeper.

Again, Clarke remarks that C. indenta, Conrad, only differs from C. lamellosa,
Sandberger, in being trellised. This is borne out by the numerous figures of it
given by Hall, which accurately agree in other respects with the German and
Devonshire forms. In only two of his figures is this trellising shown, and in them
(as in Barrande’s) it is so slight as probably to be quite superficial. It may well
be imagined that such markings might be obliterated in our shells by so rough a
matrix as that of Lummaton. C. lamellosa, Hall, seems to be only a young form
of the same shell.

It seems best, therefore, to regard both Conrad’s and Barrande’s names, at

8 DEVONIAN FAUNA.

least presumptively, as synonyms, especially as in one of Hall’s figures, the minor
transverse striz mentioned by Phillips are visible.

Hall unites Cypricardites inflata, Conrad, with C. indenta.

The English specimens and Sandberger’s, Billings’, and Hall’s figures all vary
much more in themselves than they differ from each other, and a continuous chain
might be formed by intermixing them. The German form has the shortest hinge-
line, the Canadian and Bohemian the longest. The Canadian is the largest shell,
the German the next, and the Bohemian the smallest ; but English specimens may
be found as small as any.

Affinities. —Modiola squamifera, Phillips,’ is evidently a kindred form, but
differs in so many particulars that I agree with Clarke in separating it. It is
much larger and more transverse, and has no central constriction, a longer hinge-
line, and much smaller umbones.

Cypricardia glabrata, Phillips,” also seems very similar in general shape, but
Phillips’s figure and description are too slight for comparison.

Gervillia squamosa, Phillips,’ appears to belong to the same genus, but his
figure is insufficient for specific comparison.

Cypricardia semisulcata, Phillips,’ is at once distinguishable by the divarication
of its ridges and their posterior effacement.

C. impressa, Sowerby (?), as given by Phillips,’ is much broader in front, and
has the ribs of uniform size.

Isocardia Humboldti, Honinghaus,’ as given by F. A. Romer,’ is a small
variable shell, not very dissimilar, but differing in having a smaller umbo and a
more produced anterior side, and in being decidedly less produced. Sandberger,’
without giving a reason, changes its name to Isocardia celata, and his figure is
very different from Rémer’s version of it, as well as from the present shell, from
which he distinguishes it. It shows transverse divaricating growth-lines which
suggest its identity with Cypricardia semisulcata, Phillips.

In Myacites striatulus, F. Romer,’ the umbo is so much more central that there
is no doubt that it is distinct.

Oypricardinia squamifera, F. A. Romer, as given by Maurer, has much finer
ribs, and varies much in shape, so that I doubt its identity.

1 1836, Phillips, ‘Geol. Yorks.,’ vol. ii, p. 209, pl. v, fig. 22.

2 Tbid., p. 209, pl. v, fig. 25. 3 [bid., p. 212, pl. vi, fig. 9.

+ 1841, Phillips, ‘ Pal. Foss.,’ p. 36, pl. xvii, figs. 57 a—e.

5 Thbid., p. 36, pl. xvii, fig. 58.

6 1828, Honinghaus, ‘Isis,’ p. 96, pl. i, fig. 1; and 1884-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii,

207, pl. exl, fig. 2.

7 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 14, pl. iii, figs. 10 a—e.

8 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 260, pl. xxvii, figs. 11, 11 a, 11 8.

9 1844, F. Romer, ‘ Rhein. Uebergangsgeb.,’ p. 79, pl. ii, figs. 5 a, 8.

CYPRICARDINIA. 9

2. CYPRICARDINIA STRIATISSIMA, n. sp. PI. I, figs. 9, 9 a, 10.

? 1834-40. SaNnGUINOLARIA LAMELLOSA, Goldfuss. Petref. Germ., vol. ii, p. 279,
pl. clix, fig. 12.
21881. Cypricarpinia nITIDULA, Barrande (pars). Syst. Sil. Bohéme, vol. v, p. 71,
pl. cciv, figs. 6, 5-8; pl. eclvi,
figs. 4, 22-24 only, Bt. F.
? 1889. — CRENICosTaTa, Barrois. Faun. Cale. d’Erbray, p. 167,
pl. xi, figs. 9 a—q.

Description.—Shell small, inequivalve, moderately convex, oblique, sub-
quadrate, not elongate. Umbo rather elevated, recurved, facing forwards, sharp
at the point, subproximate, situated in front of the centre, but not at the anterior
end. Hinge-line apparently rather long, slightly convex behind the umbo, and
depressed in front of it. Lunule small, deep. Escutcheon very long, defined by
a rounded angle running from the back of the umbo to the infero-posterior corner,
within which the surface is at first slightly concave and then rises to form a short,
flat, obtuse-angled hind wing. Anterior margin rather narrow, very convex.
Inferior margin gently convex, except that near the anterior side there is an
indistinct constriction. Postero-inferior corner slightly produced, rounded.
Posterior margin straight, short, oblique. - Back of the shell transversely flat,
except for a more or less definite, very shallow constriction, which runs down
from the front part of the umbo to the anterior part of the inferior margin,
rounded rapidly in front and over the post-umbonal angle. Surface covered by
forty or fifty fine, transverse, narrow, elevated, rounded ridges, separated by
rather wider furrows, which are barred with very numerous, fine, radiating
striz, that seem to vanish on the summit of the ridges. A triangular ligamental
gap apparently existing under the umbo.

Size of right valve-—Leneth 16 mm., breadth 13 mm., depth 5 mm.

Localities—From Wolborough there is a specimen in Mr. Vicary’s Collection,
and another in the Museum of Practical Geology. From Barton there is a
specimen in the Lee Collection. From Lummaton a poor specimen is in my
Collection, another doubtful specimen in the Woodwardian Museum, and another
(probably from the same place) in the Torquay Museum.

Remarks.—It is with some doubt that I have placed these six specimens
together, for some of them are too indistinct to enable us to do more than guess
their character, and the Woodwardian specimen shows no crenulations.

Mr. Vicary’s and Mr. Lee’s specimens are the only two that fully show specific
characters, and they have marked differences. The former, a left valve, has a
stronger and very anterior constriction; while the umbo of the latter, a right

VOL. II. 2

10 DEVONIAN FAUNA.

valve, seems larger and blunter, though its point is hidden in the matrix, and its
constriction is hardly at all apparent.

The shells figured by Barrois' as probably Cypricardia crenicostata, F. A.
Romer, so nearly resemble ours that Iam very much inclined to regard them as
the same species. They only differ in having the ribbing rather coarser, the
anterior wing of the left valve somewhat larger, and the constriction across the
valves more posterior and more clearly marked. Barrois notes a dissimilarity
between the valves, similar to that seen in our examples, and with each valve he
identifies species described by former authors. Of these, C. crenicostata, Kayser,’
C. lamellosa, Kayser*® (not Hall’), C. crenicostata, Maurer,’ and C. elongata,
Maurer,’ are much more definitely distinguished from the present form by several
particulars, while they probably agree with Romer’s species. F. A. Rémer’s?
original shell is, however, so unlike ours that, although his figure shows some
signs of inaccuracy, I do not think it can be the same. It differs in being much
less transverse, and in having much coarser ridges, a more defined and rearward
constriction, and a more concave anterior border.

Sanguinolaria lamellosa, Goldfuss,® is another shell that is so similar that I
am doubtful whether it may be identical. It chiefly differs from our left valve in
being rather more transverse, and in having no constriction and coarser strie.
I hardly think there are sufficient grounds for regarding it as the same.

Again, one or two of the numerous figures of C. nitidula, Barrande,® are so
exceedingly like our shells that if they represented the species they might be
well identified ; but the great majority are distinctly different, and I think prove
Barrande’s species to be identical with C. crenistria, Sandberger.”

On the whole, our present form may be considered as differentiated by the
smallness and number of its ribs, and by its very anterior and slight constriction.

Affinities. —Barrois regards as very kindred species C. lamellosa, Sandberger,"
which has a much less defined wing, more equal valves, and much coarser stria-
tions; OC. crenistria, Sandberger,' which has much coarser striations, a much

1889, Barrois, ‘ Faune Cale. d’Erbray,’ p. 167, pl. xi, figs. 9 a—g.
1878, Kayser, ‘ Abhandl. Geol. Specialk. Preuss,’ Band ii, pt. 4, p. 129, pl. xx, figs. 2, 2 a.
Thid., p. 128, pl. xx, fig. 3.
1861, Hall, ‘ Pal. N. Y.,’ vol. iii, p. 266, pl. xlixa, fig. 1 a—e.
1885, Maurer, ‘ Faune Kalk. Waldgirmes,’ p. 282, pl. ix, fig. 34.
Tbid., p. 230, pl. ix, figs. 27—29.
1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 60, pl. ix, figs. 20a, b.
1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 279, pl. clix, fig. 12.
1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. v, pt. 1, p. 71, pl. eciv, figs. 6, 5-8; pl. eclvii,
figs. 4, 1-24, Ht. F.
10 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 263, pl. xxviii, fig. 5.
N Tbid., p. 262, pl. xxvii, fig. 13.

Ve, 9.09) Sato cile

5s oT OE

CYPRICARDINIA. ll

larger anterior wing, and more definite constriction on the right valve; and
Pterinea elegans, Goldfuss,* which igs a much shorter shell, with very small
wings and coarse striations. On the other hand, he considers C. squamifera,
Phill.,* as given by Rémer,* to be clearly separated by its transverseness and
flatness; and C. alveolaria, Cihlert,’ by its elegant reticulation and more equal
valves. He also thinks that four species cited by Tromelin and Lebesconte®
from Erbray under the generic name of Granmatomysia probably all belong to his
species.

I at first thought that Cypricardia elongata, d’Archiac and de Verneuil,’ which
Barrois separates from his shell on account of its length and the absence of a
constriction, might be identical with ours; but on further examination Mr.
Roberts and I came to the conclusion that it is certainly distinct. In that shell
the beak overhangs the front margin, the greatest height is in front, and the
shell is very much longer. Sandberger,’ indeed, gives two such dissimilar figures
of it as to raise the question whether they are both one species, and these come
rather nearer to our form. However, his left valve still has no signs of constric-
tion; and his right valve, which shows the crenulations, has an almost median
umbo, and a very much produced and subacute anterior wing ; and therefore, even
allowing for specific variability, I think it clearly distinct. D’Orbigny® changes
its name to C. subelongata, as a more recent shell had been previously described
as C. elongata.

Modiola bilobata, Minster,"° while probably belonging to the same genus, is a
very differently shaped shell.

3. CYPRICARDINIA RETICULATA, Phillips, sp. Pl. I, figs. 11—18.

1841. AvicuLa (?) RETICULATA, Phillips. Pal. Foss., p. 51, pl. xxiii, fig. 88.
1854. _ — Morris. Catal. Brit. Foss., p. 162.

1 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 263, pl. xxviii, fig. 5.

* 1834-40, Goldfuss, ‘ Petref. Germ.,’ p. 186, pl. exix, figs. 9 a, b.

3 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 33, pl. v, figs. 4a, d.

4 1877, Barrois, ‘Ann. Soe. Géol. Nord.,’ vol. iv, p. 88.

> 1888, Géhlert, ‘ Bull. Soc. Géol. Fr.,’ ser. 3, vol. xvi, p. 660, pl. xv, fig. 2.

§ 1876, de Tromelin and Lebesconte, ibid., ser. 3, vol. iv, p. 611.

7 1842, d’Archiac and de Vérneuil, ‘Geol. Trans.,’ ser. 2, vol. vi, pt. 2, p. 374, pl. xxxvi,
figs. 14, lda, b.

8 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 261, pl. xxvii, figs. 14, 14 a—e.

9 1849, d’Orbigny, ‘ Prodrome,’ vol. i, p. 76.

10 1840, Miinster, ‘ Beitr.,’ pt. 3, p. 57, pl. xi, fig. 18.

12 DEVONIAN FAUNA.

1885. Cypricarpinta ELoNGATA, Maurer (not d’Archiac and de Verneuil).
‘Abhand. Grossh. Hessisch. Geol. Landes.,’
Band i, pt. 2, p. 280, pl. ix, figs. 27—29.

1888. AvicuLa RETICULATA, Htheridge. Foss. Brit., vol. i, Pal., p. 159.

1889. Cypricarpia autrata, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.—Shell small, elongate, convex, angulated, oblique. Umbo small,
recurved, rather prominent, facing forwards, situate on the anterior part of the
hinge-line. Hinge-line straight behind the umbo, sinking in front of it. Lunule
apparently rather large and deep. Hscutcheon very large, bounded by a sharply
rounded angle, which runs in a slightly sigmoid line from the back of the umbo to
the postero-inferior point, and within which it is at first decidedly concave, and
then rises to form a small, narrow, obtuse-angled hind wing. Anterior margin
obliquely concave. Infero-anterior corner slightly produced, bluntly angular.
Inferior margin oblique, slightly concave or constricted in front, and then for the
ereatest part of its length moderately convex. Infero-posterior point very much
produced, very convex. Posterior margin short, oblique. Contour of the shell
very convex vertically, slightly convex horizontally, rapidly rounding over the
post-umbonal line, and having a shallow vertical concavity or constriction close to
the anterior margin. Surface covered with twenty-five or thirty rather irregular,
low, distant ridges, between which are signs of minor lines, each ridge being
frilled upon its upper surface by fine, short, distant, radiating, discontinuous
striz, so as to give it a pitted or flounced appearance.

Size-—Length 13 mm., breadth 7 mm., depth of a single valve 4 mm.

Localities.—There are three specimens from Lummaton in my Collection, and
one, probably from the same locality,in the Torquay Museum. From Wolborough
there are four specimens in the Museum of Practical Geology, some of which are
so poor as to be almost unrecognisable.

Remarks.—While from the specimens at our command the characters of the
species can be fairly made out, their state of preservation is such as to leave some
points doubtful, and not one of them will enable a perfect figure of the shell to be
drawn.

Under the name Avicula (?) reticulata, Phillips describes a shell from Barton
which must, I think, be the same species, although there are some points of
difference in his figure which render it perplexing. I have been unable to find
his original example, and his description is too indefinite to help. The chief
differences in his figure are that the inferior margin forms one regular convex
arch without any anterior constriction, and that the anterior side seems slightly
larger. There isasign of an anterior concavity on the back, which is apparent only
near the umbo ; but from his description it would appear that he recognised it. As,
therefore, his shell clearly belongs to the genus Cypricardinia, and not Avicula,

. CYPRICARDINIA. 13

as it comes from Barton, and I know of no other shell at all like it from that
locality, and as its general shape and ornament give the impression of identity, I
am inclined to believe that the points of difference are due to the imperfection of
his specimen or of his drawing, and that our shells must be referred to his species.
It is to be remembered, moreover, that the anterior constriction often varies in
intensity in other species of the genus.

Hisinger’ previously described a different Silurian species under the name
Avicula reticulata ; but, as Phillips’s species belongs to a different genus, it may
be allowed, in Professor Rupert Jones’s opinion, to retain its trivial name.

Follman,” who would unite it with A. anisota, Phillips, observes that Phillips’s
figure bears resemblance to a Cypricardinia.

Affinities. —Sandberger’® regards Phillips’s Avicula reticulata as a synonym of
Cypricardia elongata, d’Archiac and de Verneuil,* but from that shell it differs in
its much fewer and coarser markings, its more elongate shape, and the contour of
its post-umbonal line.

It also approaches Cypricardia crenistria, Sandberger,® of which Cypricardimia
nitidula, Barrande (pars),° is a synonym, but is distinguished by its greater length,
its much smaller and less definite hind wing, its more defined post-umbonal line,
its more produced and compressed infero-posterior corner, and its short and distant
radiating striee.

Cypricardia crenicostata, F. A. Romer,’ is a much squarer and less transverse
shell.

Cypricardinia alveolaria, Ghlert,* is a much shorter and more quadrate shell.

4, CYPRICARDINIA ENSIFoRMIS, Whidborne, sp. PI. I, figs. 14—16.
1889. CyprIcARDIA ENSIFORMIS, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.—Shell small, flat, elongate, oblique, trapezoidal. Umbo appa-
rently very small, recurved, facing forwards, proximate, flattened, situate near the

1 1836-40, Hisinger, ‘ Leth. Suec.,’ p. 57, pl. xvii, fig. 18; and 1839, Sowerby, in ‘ Murch. Sil.
Syst.,’ p. 614, pl. vi, fig. 3.

2 1885, Follman, ‘ Verh. d. nat. Vereins Bonn.,’ Jahrg. 42; Verhdl., p. 204.

3 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 261, pl. xxvii, figs. 14, 14. a—e.

4 1842, d’Archiac and de Verneuil, ‘Geol. Trans.,’ ser. 2, vol. vi, pt. 2, p. 374; pl. xxxvi,
figs. 14, 14a, b.

5 18538, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 268, pl. xxviii, figs. 5, 5 a, 0.

6 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pl. celvii, fig. 4, 1-15 only, Ht. F.

7 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 60, pl. ix, figs. 20 a, b.

8 1888, (Ehlert, ‘ Bull. Soc. Géol. Fr.,’ ser. 3, vol. xvi, p. 659, pl. xv, figs. 2, 2a—d.

14 DEVONIAN FAUNA.

anterior point. Hinge-line apparently about two-thirds the length of the shell, sunk
below the angulated superior margin, straight behind the umbo and rapidly
sinking in front of it. Lunule (?). Escutcheon very large, defined by a sharply
rounded angle, running straight from the back of the umbo to the postero-
inferior point, within which it is at first decidedly concave, and then rises to form
a narrow, flat, obtuse-angled hind wing. Anterior margin narrow, oblique, and
straight. Antero-inferior point angular. Inferior margin concave in front, and
then becoming gently convex for the greatest part of its length. Postero-inferior
point very much produced and very convex. Posterior side rather short, oblique,
and concave. Back of the shell almost flat except in front, where there is a
a shallow concavity or constriction; rounded rapidly over the anterior side and
post-umbonal angle. Surface covered with between thirty and forty sharp,
smooth, obtusely angulated, distant ridges, divided by similarly angled grooves,
without any radiating marks, and following the marginal contour except that of
the upper margin, by which they are truncated; these ridges being fine and small
on the anterior lobe, becoming gradually larger till they pass the post-umbonal
line, and then becoming suddenly much finer and uniform upon the hind wing.
Shell-structure thin.

Size-—Length 17 mm., breadth 11 mm., depth of one valve 3 mm.

Localities.—There are three specimens from Lummaton in my Collection ;
another, perhaps from Wolborough, in the Battersby Collection of the Torquay
Museum; and another, from Barton, in the Lee Collection of the British Museum.

Remarks.—This shell appears to have been very fragile, and all the specimens
I know of it are fragmentary, except the one in the British Museum, which,
although not so flat, and differing in some other points, I believe to belong to the
same species, and therefore to enable us to arrive at its true outline.

From the accompanying forms it is easily distinguished by its flatness, its fine,
smooth, angulated ribs, and its general contour.

From C. elongata, d’Archiac and de Verneuil, as given by them’ and by
Sandberger,” which seems its closest ally, it is separated by its greater flatness, its
small constricted anterior lobe, its smaller umbo, and its smooth ribs. It is true
that the former authors do not mention radiations on the ribs of their shell, but
there is every reason to believe it to be the same species as Sandberger’s, on
which they are noted.

Sanguinolaria wndata, Minster,’ is rather similar in ornament, but very
dissimilar in shape, and has clearly no real affinity with it.

1 1842, d’Archiac and de Verneuil, ‘Geol. Trans.,’ ser. 2, vol. vi, pt. 2, p. 374, pl. xxxvi,
figs. 14, 14a, b.

2 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 261, pl. xxvii, figs. 14, 14 a—e.

3 1840, Miinster, ‘ Beitr.,’ pt. 3, p. 73, pl. xii, fig. 27.

ISOCARDIA. 15

2. Genus.—Isocarpra (Klein, 1753), Lamarck, 1799.

Whether the Paleozoic forms referred to this genus really belong to it seems to
be doubtful, and in the species described below the hinge is not sufficiently
exposed to permit comparison. Shells have been described as fae a to this
genus from the Silurian to the present time.

1. Isocarpia Croxkeri, n. sp. Pl. I, figs. 11, 11 a.

Description. — Right valve ovoid, convex, suborbicular. Umbo large,
prominent, facing anteriorly, and situate at about the anterior third of the
hinge-margin. Anterior margin produced, narrow, and very convex. Inferior
margin slightly convex. Posterior margin narrow, apparently subangular.
Hinge-margin very convex. Hinge (only partly seen) with two long, narrow, low
lateral teeth, separated by narrow grooves. Contour of back convex, bounded on
the postero-superior side by a sharp, curved, overhanging angle, which runs from
the back of the umbo to the posterior point, and separates an oblique, flat, lancet-
shaped area, so that the valves meet above at more than two right angles. Shell-
structure massive. Interior of valve unseen.

Size.-—Length 20 mm., breadth 19 mm., depth of single valve 9 mm.

Locality— There is a single specimen from Wolborough in Mr. Vicary’s
Collection.

Remarks.—I have not met with any described species corresponding with this
fossil, and as the hinge is much obscured IJ have found it difficult to decide its
genus. On examining the specimen in conjunction with Mr. R. Etheridge, F.R.S.,
we came to the conclusion that it most probably was a species of Jsocardia, and
in that opinion I am confirmed by the general likeness it bears to other paleozoic
species which have been referred to that group.

It has been suggested that it might be a young specimen of Megalodon
cucullatus, Sow.,! but a comparison of it with Sowerby’s and Goldfuss’s figures,”
and with numerous foreign specimens of all sizes in the British Museum, proves
that this is not the case. The present shell is much longer, its umbo is smaller
and more oblique, its anterior side is much larger and more convex, and the
exposed part of its hinge does not correspond. Goldfuss describes that shell as

1 1829, Sowerby, ‘ Min. Conch.,’ vol. vi, p. 182, pl. dixviii.
2 1834-40, Goldtuss, ‘ Petref. Germ.,’ vol. ii, p. 183, pl. exxxi, figs. 8 a—d.

16 DEVONIAN FAUNA.

having a blunt keel surrounding the area as in our shell, but as having a distinct
lunule, which our shell has not.

Affinities.— Thetis (?) trigona, F. A. Rémer,! seems from the description to
have a similar truncated area, but it differs in its general shape, being more
transverse and much less produced anteriorly.

3. Genus.—GontopHora, Phillips, 1848.

Shell transversely oblique, equivalve, very inequilateral. Umbo recurved,
proximate, anterior, arching forward, very much compressed, so as to form a sharp
elevated keel, which runs down the centre of the back to the base. Hinge-line
nearly straight, bearing on the left valve along oblique tooth between two grooves,
angulated at its extremities. Surface covered with concentric ornament. Lunule
small, deep.

Phillips named his genus without description. It is generally referred to the
Cyprinide. The general external resemblance of the fossil described below to the
type species Goniophora cymbeformis, Sowerby, sp.,” makes me believe that it
must belong to the present genus. At the same time the only figures of the hinge
which I have been able to find are some given by Hall, who classes it under the
Mytilidz, and these are so different as to cause doubt whether the American
forms have any real kinship to the present shell.

This genus has been described from the Silurian and Devonian formations.

1. GontopHora oBLiqua, Whidborne, sp. Pl. UI, figs. 1, la, 1b.

1841. Mre@anopon carrnatum, Phillips (not Goldfuss). Pal. Fos., p. 136, pl. lx,

figs. 60* a, 6.
1854. MraaLopon carinatvs (not Goldfuss), Morris. Catal. Brit. Foss., p. 209.
1888. — — Etheridge. Foss. Brit., vol. i, Pal., p. 161.
1889. — OBLIQUUS, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 78.

Description.—Left valve large, oblique, deep, subquadrate or rhomboidal.
Umbo large, prominent, elevated, oblique, proximate, incurved, and facing
anteriorly, situated about the centre of the hinge-margin, compressed laterally so
as to form a sharp erect keel, which is continued in a slightly curving line to the
inferior point, and which gradually becomes more rounded and stouter in that
direction. Hinge-margin rather short, nearly straight, terminated by an angle
of about 60° in front, and by a very large angle behind. Anterior margin very

1 1848, F. A. Romer, ‘ Verst. Harzgeb.,’ p. 26, pl. vi, fig. 25.
2 1839, Sowerby, in ‘Murch. Syst. Sil.,’ p. 602, pl. iii, fig. 10, and pl. v, fig. 6.

GONIOPHORA. 17

narrow and convex. Antero-inferior margin very long, undulating in two gentle
convex and concave curves to the produced inferior point. Posterior margin
long, straight, oblique. Postero-inferior margin oblique (?). Contour of shell in
front of the keel obliquely flat, and behind the keel obliquely concave. Lunule
very small and deep, cordate, defined. Hinge-line bearing one if not two small
oblique teeth on each valve below the umbo, and, perhaps, a long, transverse,
lateral tooth behind. Surface in front of the keel marked with very numerous,
straight, erect, sharp, foliaceous, transverse, divaricating ridges or threads, and
behind it apparently only with a few growth-lines. Shell-structure very thin.

Size—The only specimen I know is too imperfect for measurement. It
seems to have been a considerably larger shell than Phillips’s, whose figure
measures 74 mm. in greatest length.

Locality.—A single specimen from Wolborough is in the Museum of Practical
Geology.

Remarks.—This specimen consists of the superior half of a left valve, and in
the above description I have used Phillips’s figure to supply as far as possible
characters which are not seen in it. Phillips’s type I have been unable to find,
but there is not the slightest doubt that it belonged to the same species, as it
corresponds with it in every particular. It is quite dissimilar from any other
fossil from these localities. The Museum specimen is not in a very good state of
preservation, and the hinge-line shows signs of having been considerably weathered.
The general shape of its teeth is, however, clear. There is a small, narrow,
oblique tooth under the umbo in front of a narrow groove, and preceded by
another small, deep, triangular groove, which in turn is preceded by another
small tooth. The shell appears to have been very deep, and of a peculiar shape,
being produced obliquely backwards from a rather short straight hinge-line to a
sharp inferior corner, and not being simply elongate, as would be imagined from
the position of Phillips’s figure.

Phillips is undoubtedly wrong in identifying it with Megalodon carinatus,
Goldfuss. Its external shape is distinctly different, and its hinge is totally
unlike, and proves at once that it has no affinity with that shell.

Goniophora gallica, Gihlert,t has a longer hinge-line, and appears to be a
more evenly rounded shell.

All the species of Goniophora described by Hall differ in having very much
longer hinge-margins, except G. truncata, Hall,’ whichis radiated and more arched
anteriorly, and G. Glaucws, Hall,’ which is more oblique and has a longer hinge-
margin and a differently shaped hinge.

1 1888, ‘ Bull. Soc. Géol. Fr.,’ ser. 3, vol. xvi, p. 657, pl. xv, fig. 5.

1885, Hall, ‘ Pal. N. Y.,’ vol. v, pt. 1, sect. 2, p. 298, pl. xlii, figs. 9,10; and pl. xliv, figs. 1—8.

3 1885, Hall, ‘ Pal. N. ¥, vol. v, pt. 1, sect. 2, p. 299, pl. xliii, fig. 16; and pl. xliv, figs. 1O—17.
VOL. Il. 3

18 DEVONIAN FAUNA.

II. Sus-orper.—INTEGRIPALLIATA, d@’Orbigny, 1843.
I. Family.—Carvipm, Swainson, 1837.

1. Genus.—Conocarpium, Bronn, 18385.

PLEevRORHYNONUS, Phillips, 1836.

Though this well-defined genus is evidently very nearly allied to Cardiwm,
there seems much diversity of opinion as to the position of the animal in the
shell. The truncated rostral end is regarded as the anterior side by most authors,
e.g. M‘Coy, Zittel, Fischer, and Barrois, the gape on the triangular side being, in
that case, for the passage of the syphons. Tryon, on the other hand, comparing
it with Adacna, regards it as inverted, and in that case the gaping end would be
anterior and the aperture would be for the foot. It seems to me that the former
is the most probable supposition, though something may be said for both views.
The following descriptions, therefore, treat the rostral side as anterior. Mihlert
refers it to the family Lithocardiide of Munier Chalmas.

It extends from the Silurian to the Carboniferous.

For the purposes of description Barrois divides the test into the following
regions from front to back :—1, Rostrum ; 2, anterior cordiform slope ; 3, anterior
keel; 4, median region; 5, median ridge; 6, posterior slope; 7, posterior sinus;
8, conical aliform protuberance.

The species appear to be numerous, and as some of the earlier specific descrip-
tions are very much generalised, it is far from easy to decide the synonymy. In
the localities under notice the genus is well represented both in species and
individuals.

1. Conocarpium cLaTHRATUM, d@’Orbigny. Pl. I, figs. 17—20, and Pl. II, figs. 1—3.

1834-40. CaRDIUM ALIFORME, Goldfuss (pars), not Sowerby. Petref. Germ., vol. ii,
p- 218, pl. exlii, figs. a and g (only).
1841, PLEURORHYNCHUS ALIFORMIS, Phillips. Pal. Foss., p. 34, pl. xvii, fig. 51;
and pl. lx, fig. 51.

1842. CaRDIUM ALMFORMD, var. CLATHRATUM, ad’ Archiae and de Verneuil. Geol.
Trans., ser. 2, vol. v, pt. 2, p. 874, pl. xxxvi,
figs. 7, 7a.

1843. PLEURORHYNCHUS ALHFORMIs, F. A. Romer. Verst. Harzgeb., p. 22,

pl. vi, figs. 5 a—e.

1849. CoNnocaRDIUM CLATHRATUM, d’Orbigny. Prodrome, vol. i, p. 80.

CONOCARDIUM. 19

1853. CaRDIUM CLATHRATUM, Steininger. Geogn. Beschr, Eifel, p. 51.
1854. Conocarpium aLirorME, Morris (pars). Catal. Brit. Foss., p. 194.

1871. — OxntornsE, Meek. Proc. Acad. Nat. Sci. Philad., p. 8.
1876. — CLATHRATUM, Ff, A. Romer. Lethea Pal., pl. xxix, figs. 4, 4a.
1884. — ALIFORME, Clarke. Neues Jahrb. f. Min., Beil.-Band_ iii,
p. 379.
? 1884. _— — Tryon. Struct. Conch., p. 195, pl. exvi, fig. 93.
1885. —_ — Maurer. Abhandl. Grossh. Heasisch. Geol.

Landes., Band i, pt. 2, p. 225,
pl. ix, figs. 18, 18 a.
? 1885. _ ViILLMARENSE, Maurer. Ibid., p. 226, pl. ix, figs. 19, 19 a,
20, 20a.
1888. PievRORHYNCHUS aLiForMIS, Etheridge. Foss. Brit., vol. i, Pal., p. 162.
1889. ConocarDIumM vExatuM, Barrois. Faun. Cale. d’Erbray, p. 167, pl. xi,
figs. 8 a—d.

Description.—Sheli small, equivalve, slightly transverse, truncated in front but
with a long tubular rostrum, conical behind. Umbo direct, incurved, rather pro-
minent, subproximate, situated near the anterior side. Hinge-line long, nearly
straight, slightly arched behind, slightly sunk below the rounded superior margin.
Anterior margin produced to form the rostrum above, straight, and nearly perpen-
dicular below. Inferior margin narrow and nearly horizontal, slightly convex.
Posterior margin oblique, slightly concave, meeting the hinge-margin at an acute
angle. Anterior cordiform slope large, extending to the antero-inferior corner,
flatly convex, only becoming slightly concave near the springing of the beak,
ornamented by close, low, rounded ribs, the outer of which are superiorly truncated
by the anterior keel. Anterior keel prominent, reaching nearly to the lowest point
of the shell. Median region rather narrow and convex, ornamented by six or seven
coarse, prominent, high, flattened ribs, which are separated by spaces of at least
similar width and spring from the umbo, bounded posteriorly by a more or less
indistinct median ridge. Posterior side horizontally oblique and nearly flat, conical,
ornamented with similar ribs springing from behind the umbo. The whole surface
covered by numerous, rather distant, minute, raised, concentric threads, which are
generally closer on the cordiform slope. Supero-posterior edge somewhat gaping.

Size.— Length 18 mm., breadth 13 mm., depth 10 mm.

Localities.—This shell is decidedly common at Lummaton. In my Collection
there are thirty specimens, in the British Museum three specimens, in the Torquay
Museum two specimens, and in the Woodwardian Museum three specimens. From
Wolborough there are three specimens in Mr. Vicary’s Collection, five in the
Museum of Practical Geology, and one in the Torquay Museum.

Remarks.—Although these shells are so common, their specific limits are not
very easy to define, as they show considerable variation in shape, and their orna-
mentation and structure seem peculiarly liable to be masked by fossilization.

20 DEVONIAN FAUNA.

They have been usually referred to Cardium aliforme, Sowerby, but. it
will be seen that the name which they should rightfully bear is probably C.
clathratum.

CO. aliforme, Sowerby,’ was first described in the ‘ Min. Conch.,’ from Queen’s
County, Ireland, and, as seen both from that description, and from the original and
other specimens in the British Museum, it is distinctly different from the present
form. It is a larger and much less angulated shell ; the ribs on the median region
are much more numerous and more distant; the anterior slope is distinctly
concave ; and the ribs on the posterior wing are much larger. De Koninck points
out its distinctness, and says that the following have been wrongfully identified
with it:—Bucardites hystericus, Schlotheim,’ OC. dverswm, Honinghaus,*® Pl.
aliformis, Phillips, Lichas antiquus, Steininger,* Cardium elongatum, Bronn,°
O. elongatum, Goldfuss,® and C. aliforme, Goldfuss, and d’Archiac and de Verneuil.

Under the name of Sowerby’s shell, Goldfuss’ described as varieties several
distinct Carboniferous and Devonian forms. Of these, his two figures, pl. exlii,
fis. a and g, alone appear to represent the present species.

Phillips, in the ‘ Pal. Foss.,’ divides his Devonshire specimens into two species,
QO. aliforme and C. aninaw, Phillips.” The two figures which he refers to the
former clearly belong to the present form, and the original of one of them I find
among the specimens in the Museum of Practical Geology. His so-called Devonian
C. minax is distinguished by its smaller and distinctly concave cordiform slope, its
broader median region, which contains many more ribs, and the large size of the
ribs onthe conical aliform protuberance. The defective shell figured as C. aliforme
by Sowerby,’ from Stonehouse Hill, Devon, appears to agree with this latter species,
and shows similar distinctions, though a crushed Lummaton example of our
present shell, which is in my Collection, mimics its general shape.

D’Archiac and de Verneuil give as. CU. aleforme, var. clathratum, Goldfuss
(referring to his fig. 1g), a shell which differs from ours only in having the median
ridge rather more pronounced, and which therefore, in all probability, belongs to
this present species.

F. A. Romer gives an indistinct figure of Pl. aleformis, Sow., which, from his

1 1827, Sowerby, ‘ Min. Conch.,’ vol. vi, p. 100, pl. dlii, fig. 2.

2 1820-2, Schlotheim, ‘ Petrefack.,’ vol. i, p. 207 ; vol. ii, p. 63, pl. xx, figs. la—e.

3 1830, Héninghaus, ‘ Jahrb. f. Min., p. 236.

4 1853, Steininger, ‘ Bull. Soc. Géol. Fr.,’ vol. viii, p. 281, figs.

5 1837, Bronn, ‘ Letheza,’ p. 92, pl. ili, fig. 9.

6 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. v, p. 218, pl. exlii, fig. 2.

7 Tbid., p. 214, pl. exlii, figs. 1 a—m.

8 1836, Phillips, ‘Geol. Yorks.,’ vol. ii, p. 210, pl. v, fig. 27; and 1841, Phillips, ‘ Pal. Foss.,’
p- 33, pl. xvii, figs. 50a, b.

9 1840, Sowerby, ‘ Geol. Trans.,’ ser. 2, vol. v, pt. 3, pl. lvi, fig. 2.

CONOCARDIUM. 21

description, is doubtless the same ; although Clarke, who states it to be rare in the
Iberger Kalk, unites it with Sowerby’s, and separates it from d’Archiac and de
Verneuil’s shell.

C. clathratwm, Steininger, is identified by him with d’Archiac and de Verneuil’s
Shell, and also apparently with our English shells.

The shells which Sandberger’ figures as C. aliforme, Sow., are rather perplexing.
His figures have the appearance of being slightly idealized. While agreeing with
ours in many respects, they are decidedly more rounded and more transverse,
and have fewer median ribs. hey seem to correspond better with C. pugnans
than with the present form.

It appears to me that the shell described by Barrois’ as a variety of Conocardiwm
vewatum, Barrande,® may be a young form of this species ; for some of the smaller
Lummaton specimens seem to correspond with it, and, though their shape some-
what changes with their size, I see no reason for separating them from the larger
specimens from the same place. Barrande’s original C. vewatwm is, however,
distinctly different. It has a wider median region, with much more numerous ribs.

I can find no distinguishing features in C. Ohioense, Meek, which I am, there-
fore, obliged to consider as identical.

Affinities —I am very doubtful whether C. Marsi, Ghlert,* is distinct from
C. clathratum, either as originally defined or as represented by our shells. iuhlert
distinguishes it from d’Orbigny’s species as being more transverse, and as having
the median region less flattened, more oblique, and not bounded behind by a
stronger ridge, but passing insensibly into the posterior part. Judging from our
specimens, many of these distinctions fail. It is true that in our fossils the
rib of the median keel is never actually stronger than the others, but in some of
them the keel itself is sufficiently prominent, and considering their variability there
seems no possibility of separating them from the German form. Comparing them
with (ihlert’s figures, there seem to be some small distinctions; as in the latter
the superior margin seems more convex, the umbo less prominent, the shape more
trigonal, the back more oblique and narrower. In C. Marsi, as given by Barrois,’
these distinctions are still more pronounced, and moreover the height is definitely
greater and the median ribs alternate. In face of these points I do not feel justified
in uniting the species at present.

Minster figures several species which evidently belong to this genus, but are
as evidently not accurately represented. Of these, Cardiwm propinquum, Mimnster,®

1 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 257, pl. xxvii, figs. 6 a—d.

2 1889, Barrois, ‘ Faun. Kalk. d’Erbray,’ p. 167, pl. xi, figs. 8 a—d.

3 1881, Barrande, ‘Syst. Sil. Bohéme,’ vol. v, pt. 2, pl. exev, figs. 1, 1-3, Et. G.
4 1887, Gthlert, ‘ Ann. Sci. Géol.,’ vol. xix, p. 15, pl. i, figs. 23—81.

» 1889, Barrois, ‘Faune Kalk. d’Erbray,’ p. 160, pl. xi, figs. 4 a—d.

6 1840, Miinster, ‘ Beitr.,’ pt. 3, p. 59, pl. xii, figs. La, b.

22 DEVONIAN FAUNA.

differs from this and our other English species in having its anterior slope much
more rounded and its radiations finer. Allowing for the inaccuracy of the figure,
it is just possible that Cardiwm semialatum, Minster,’ may be identical. The
number and prominence of the ribs are the same, and the general shape not alto-
gether dissimilar, though, as the posterior projection seems narrower, more pro-
duced, and smooth, and the median region passes insensibly into the posterior, it
may be best not to unite them without further evidence. In C. paucicostatum,
Minster,” the ribs are fewer, and the posterior projection larger and more definitely
smooth.

QO. cuneus, Conrad,* as given by Hall,* is very similar, but differs in being
much larger, and in having the anterior slope concave, and the median region
much wider and passing insensibly into the posterior region.

C. Bohemicum, Barrande,’ generally has a more rounded anterior slope, and a
larger median region with many more ribs. One or two of his many figured
Specimens seem less distinguishable in these respects, and might, perhaps, be
united with our shell, were it not that they are evidently variations of a species
which is usually quite distinct. In every case the posterior sinus is much higher.

C. deletwm, Barrande,® has a stronger anterior ridge and a concave anterior
slope, and is a much shorter and squarer shell.

CO. artifex, Barrande,’ has a much more distinct posterior sinus, a narrower
and generally more oblique median region, and more numerous ridges on the
anterior slope.

CQ. trigonale, Phillips, as given by de Koninck,*® has many more ribs in the
median region, which is wider and more defined.

Some of the medium-sized figures of Conocardium quadrans, Barrande,’ seem
hardly distinguishable from it, but on the whole that Bohemian species seems to
be more finely ribbed, its median region is narrower, and there is a strong sharp
sinus between the posterior slope and posterior aliform protuberance.

Cardium crenatum, Steininger™ seems to be a much larger and less transverse

1 1840, Minster, ‘Beitr.,’ pt. 3, p. 59, pl. xiii, figs. 1a—e.

2 Thid., pt. 3, p. 59, pl. xiii, fig. .2.

3 1840, Conrad, ‘Geol. Surv. N. Y. Ann. Report,’ p. 206.

4 1885, Hall, ‘Pal. N. Y.,’ vol. v, pt. 1, sect. 2, p. 409, pl. Ixvii, figs. 1—31; pl. Ixviu, figs. 1,
4--16 ; pl. xciv, figs. 11, 12.

» 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pl. exevi, figs. 1—43; pl. excvii, figs. 1, 1-20, and
2, 1-20, Ht. F.

6 1881, Ibid., pl. exev, figs. 1, 4-6, Ht. G.

7 Thid., pl. excix, figs. 2, 1-35, Ht. F.

8 1885, de Koninck, ‘Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. 5, p. 103, pl. xli, figs. 15—20.

9 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pl. ce, figs. 2, 1-32, Ht. F.

10 1853, Steininger, ‘Geogn. Beschr. Hifel,’ p. 51, pl. iti, figs. 4a, 6, 5a, 6.

~CONOCARDIUM. 23

species with a more convex posterior margin, and its median and posterior
regions are completely merged.

2. Conocarpium Marsi, Cfhlert (?). Pl. IX, figs. 12, 12 a.

1850. ConocarpiIumM chaTrHRatuM, de Vernewil. Bull. Soe. Géol. Fr., ser. 2,
vol. vii, p. 779.

1877. — ALIFORME, Ghlert. Ibid., ser. 3, vol. v, p. 592.

1882. = cLaTHRATUM, Barrois.. Rech. Terr. Anc. Asturies, p. 277.

1887. — Marst, @hlert. Ann. Sci. Géol., vol. xix, p. 15, pl. 1,
figs. 283—81.

1889. — — Barrois. Faun. Cale. @Erbray, p. 160, pl. xi,
figs. 4a—d.

Description.—Shell very small, equivalve, high, truncated and rostrated in
front, very conical behind. Umbo direct, incurved, small, situated near the
anterior side. Anterior margin straight and perpendicular below the rostrum.
Inferior margin very narrow and oblique. Posterior margin oblique and nearly
straight. Anterior cordiform slope very large, flat, slightly produced in the centre,
ornamented by numerous close low rounded ribs, of which the outer are truncated
by the anterior keel, which extends to the lowest point of the shell. Median region
very narrow, ornamented with five alternating, close, rounded ribs. Median keel
indistinct. Posterior slope slightly concave, with about eight narrow, close ribs,
divided by deep furrows. Posterior region with broader close ribs. Surface
apparently crossed by irregular growth-lines.

Size.-—Length 7 mm., breadth 8 mm., depth 8 mm.

Locality.—There is a single specimen in the Torquay Museum, which appa-
rently came from Lummaton or Barton.

Remarks.—W hether this is more than a small variety of O. clathratum is very
doubtful, but it is distinguished by several particulars. Its great depth gives it
the appearance of being a full-grown shell. Its shortness, its very narrow
median region bearing close alternating ribs, its narrow posterior region with
very broad ribs, and the apparent absence of regular transverse striaw, seem on
the whole to suggest its identity with C. Marsi, Ghlert, at least as given by
Barrois. Our specimen is, however, not sufficiently good to permit of certainty
on the point.

24 DEVONIAN FAUNA.

3. Conocarpium pUGNANS, Whidborne, sp. Pl. I, figs. 4, 4.a—e, 5, 5a.

1840. CARDIUM ALIFORME, var. a, Goldfuss (pars). Petref. Germ., vol. i, p. 218,
pl. exhi, figs. 1 b—d (only).

P 1853. — —_— Sandberger. Verst. Rhein. Nassau, p. 257, pl. xxvii,
figs. 6, 6 a—d.
1853. — — Steininger. Geogn. Beschr. Eifel, p. 51.

1889. PrEevRoRHYNcHUS PUGNANS, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.—Shell small, very elongate, equivalve, convex, subconoidal behind,
truncated and rostrated in front. Umbo direct, incurved, rather prominent,
proximate, situated near the anterior side and truncated anteriorly. Hinge-line
very long, straight, slightly sunk below the rounded superior margin. (Rostrum
unseen in any specimen.) Anterior margin horizontally produced above to form
the rostrum, and long, straight, and nearly perpendicular below. Inferior and
posterior margins forming one oblique and nearly straight line, which becomes a
little arched as it meets the hinge-margin. Anterior cordiform slope very large
and nearly flat, slightly elevated in the centre, extending to the lowest point of
the shell ; covered by very low, fine, concentric, rounded, close ribs, of which the
outer. are truncated superiorly by the carina. Anterior keel acute, sometimes
rather sigmoid, reaching to the extreme antero-inferior corner. Median region
very narrow, oblique, slightly convex, bearing only three or four unequal ribs.
Median keel undeveloped. Posterior slope rather broad and shallow. Posterior
region elongated, slightly convex. Ribs of the median and posterior regions
coarse, low, and about their own widths apart, springing from the umbo
and the part of the hinge-margin immediately behind it. The whole surface
covered by very numerous, close, microscopic threads. Greatest depth of the
shell on the anterior keel. Gape of the supero-posterior edge narrow and
rather lone.

Size-—Length 10 mm., breadth 8 mm., depth 6 mm.

Locality.—Lummaton. There are eight specimens in my Collection and one
in the Woodwardian Museum.

Remarks.—The distinctive characters.of this species are its transverse
conoidal shape, its very minute and close concentric threads, its very large
anterior slope with very flat and slightly marked ribs, and the few unequal ribs
of its median region. ‘There appears to have existed an outer layer of shell ;
it is generally absent, but almost entirely masks the ribs on the anterior side
when it is present.

This form appears to agree exactly with one of the shells figured as Cardiwm

~CONOCARDIUM. 25

aliforme, by Goldfuss,’ but to differ distinctly from the rest of those which he
groups with it under “ var. a.”’”

The shells referred to C. aliforme by Sandberger are so similar that, allowing
for individual variation and a little artistic idealization, both of which are apparent
in his drawings, they may be regarded as probably identical. The chief
differences observable are a broader rostrum, a wider median region, and more
rounded and undulating margins.

Affinities.—In some respects this shell presents a resemblance to C. clathratum,
d’Orbigny, but its decidedly greater length, its smaller size, its conical shape,
its few unequal median ribs, the closeness and fineness of its transverse threads,
and some other points, added to a general air of similarity in all our specimens,
induce me to regard it as a distinct species.

The Devonian shell referred by Phillips to Pl. minax* (with which I formerly
identified this species) while agreeing in its transverseness, differs specifically
in many other particulars. It is much larger, its anterior slope is small and con-
cave, its inferior margin is convex, its anterior keel is in front of the greatest
height, and the ribs on the median region are much more numerous, while those on
the posterior projection are very much larger. From the Carboniferous specimens
of Pl. minax, Phillips,* in the British Museum it is also certainly distinct.

Of the species described by Barrois from Erbray three only could be con-
founded with it. Of these, C. refleewm, Zeiler,’ is the nearest, and corresponds in
the fineness of its concentric strize, but is distinguished by the much larger
number of ribs (8—9) on the median region, the much greater convexity of the
posterior and inferior margins, its sharper anterior keel, and its more convex
anterior slope, which moreover according to Zeiler, but not to Barrois, has more
serrated ribs than those of the median region.

Conocardium nucella, Barrande,’ and C. Chlerti, Barrois,’ differ in the same
particulars, as well as in the coarseness of their concentric striz and the greater
distance of their ribs.

Conocardium retuswm, Maurer,® which seems to be identical with Lichas antiquus,

1 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 218, pl. exli, figs. 1 b—d (only).

2 Thid., figs. a and g.

3 1841, Phillips, ‘ Pal. Foss.,’ p. 33, pl. xvii, figs. 50 a, 6.

4 1836, Phillips, ‘ Geol. Yorks.,’ vol. ii, p. 210, pl. v, fig. 27.

5 1857, Zeiler, ‘ Verh. d. Nat. Vereins, Bonn,’ vol, xiv, p. 48, pl. iii, figs. 4—8 ; and 1889, Barrois,
‘Faun. Cale. d’Erbray,’ p. 164, p. xi, figs. 7 a—h.

6 1881, Barrande, ‘Syst. Sil. Bohéme,’ vol. vi, pl. excix, figs. 1, 1-16, Ht. F; and 1889, Barrois,
‘Faun. Cale. d’Erbray,’ p. 162, pl. xi, figs. 5 a—f.

7 Ibid., p. 163, pl. xi, figs. 6 a—d.

8 1885, Maurer, ‘Abhandl. Grossh. Hessisch. Geol. Landes.,’ Band i, pt. 2, p. 227, pl. ix,
figs. 22—26.

VOL. IL. A

26 DEVONIAN FAUNA.

Steininger,’ and of which there is a German example in the British Museum,
seems extremely similar. In that species, however, the anterior slope seems
more concave, the anterior keel trends more forward, the median region is wider
and more convex, and has more regular ribs, and the concentric marks are
coarser. It therefore seems to be distinct.

4. Conocarpium HystuRIcuM, Schlotheim, sp. Pl. II, figs. 6, 6a, 66, 7, 7a.

1820. BucarpirEs uysteRicus, Schlotheim. Petrefact., p. 207.

1822. — — — Nachtr. Petref., p. 63, pl. xx,
figs. La—e.

1830. CarpiuM InvERSUM, Honinghaus. Jahrb. f. Min., p. 286.

1840. — PAUCICOSTATUM, Minster. Beitr., pt. 3, p. 59, pl. xiii, fig. 2.

1843. PLEURORHYNCHUS TRAPEZOIDALIS, F. A. Romer. Verst. Harzgeb., p. 22,
pl. vi, figs. 6 a—e.
1884. CoNnocaRDIUM HyYSTERICUM, Clarke. Neues Jahrb. f. Min., Beil.-Band iii,
p. 379.

Description.—Shell small, equivalve, very convex, short, more or less rounded,
anteriorly truncated, but with a small anterior rostrum. Umbo direct, incurved,
sub-proximate, rather prominent, situate considerably in front of the median line.
Anterior margin horizontally produced to form the rostrum, and then becoming
nearly perpendicular below. Inferior margin rather narrow, convex. Posterior
margin oblique, slightly convex, meeting the hinge-line at a high angle. Hinge-line
long, decidedly convex behind, slightly sunk below the rounded superior margin.
Anterior cordiform slope produced, slightly concave, ornamented by low rounded
concentric ribs, the outer of which are truncated superiorly. Anterior keel
oblique, generally reaching the anterior margin above the lowest point of the shell.
Median region convex, rather broad, sometimes oblique, ornamented by. about
eight ribs. Median keel not very distinct. Posterior slope well defined,
concave. Posterior region rather convex, ornamented with seven or eight ribs.
Conical aliform protuberance without ribs. Ribs of median and posterior regions
large, coarse, flat, close, divided by deep furrows, and crossed by fine irregular
and indistinct growth-lines. Gape of supero-posterior edge very large and wide.

Size.—Length 11 mm., breadth 10 mm., depth 10 mm.

Locality—There are four specimens from Chudleigh in Mr. Vicary’s
Collection.

Remarks.—There is a considerable amount of variation in the general shape
of these specimens, which renders them rather difficult to describe specifically,

1 1836, Steininger, ‘ Bull. Soe. Géol. Fr., vol. viii, p. 231, figs.

CONOCARDIUM. 27

especially as they are not very perfect. At the same time there is a general
similarity between them which shows that they all belong to one species.

It appears to me that there is every reason to believe that this species is the
true Bucardites hystericus of Schlotheim. His figure exactly corresponds in
every particular with one of ours (fig. 7). Our other examples seem less globose
shells, and have a larger anterior slope; but their similarity in gape, ornament,
and other points makes it impossible to separate them.

Clarke, who has had the opportunity of examining Schlotheim’s original
example, considers that Pl. trapezoidalis, F. A. Romer, is undoubtedly identical
withit. From Rémer’s figure it appears squarer and more produced at the postero-
inferior part; but, as it seems similar in other respects, I have Waele it as
synonymous on Clarke’s authority.

Cardium paucicostatum, Mimster, seems to correspond in the coarseness,
shape, and comparative smoothness of its ribs, and the absence of ribs on its
posterior aliform projection. It certainly differs in shape, and seems smoother
than the English shell, but this may perhaps be due to the evident inaccuracy of
Minster’s drawing.

Affinitves.—This species comes so close to C. clathratum that I have been in
doubt whether to regard it as more than one of its varieties. There seem, how-
ever, to be several distinctive features which go to prove that it is a separate
species. Thus the gape is much wider and larger ; the ribs are coarser, and those
on the posterior region are very square, close, and flat, and their interspaces very
narrow and deep; the transverse ornament does not consist of regular raised
threads, but of ordinary indistinct growth-lmes ; and the aliform posterior
projection is almost smooth, instead of being ribbed. I think that these differences
are too great to be accounted for by the local conditions under which the sedi-
ment at Chudleighwas formed.

Conocardium bifurcans, Barrande,' differs from it in its narrower and more
distant ribs, the strength of its anterior keel, and the greater concavity of the
cordiform slope.

5. Conocarpium Parties, d Orbigny.
1840. Carpium aLirormeE, Sowerby. Geol. Trans., ser. 2, vol. v, pt. 3, pl. lvi,
fig. 2
1841. PrevRoRHyNcHUS MINAX, Phillips. Pal. Foss., p. 38, pl. xvii, figs. 50 a, d.
1849. ConocarDium PuHrLiiest, @ Orbigny: Prodrome, vol. i, p. 80.
1854. — MiInAX, Morris. Catal. Brit. Foss., p. 195.
1889. PLEURORHYNCHUS MINAX, Etheridge. Foss. Brit., vol. i, Pal., p, 162.

1 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pt. 1, pl. ecii, figs. 4, 1-4, Et. E.

28 DEVONIAN FAUNA.

Description.—* Deltoidal ; anteriorly gibbous, rounded, with a contracted,
subconeave, cordiform space around the umbo; posteriorly elongated, conoidal ;
beaks anterior, surface radiated with many equal ribs, except on the cordiform
anterior space, where they are much finer than on the other part, and are
distinctly cut off by the carina which bounds the depression”? (Phillips’s
‘Pal. Foss.’).

Localities.— Bradley ;” ‘* Halberton, north-east of Tiverton.”

Remarks.—I have met with no shell agreeing with this form, and consequently
can form no judgment as to its specific value. It probably came from the
Wolborough Quarry, as the name ‘‘ Bradley” seems to have been formerly used
for that place, which is not far from the grounds of Bradley House.

Judging from the figure given in the ‘ Pal. Foss.,’ it is widely different
from O. clathratum and the other accompanying forms. It seems distinguished
by its small and concave anterior cordiform slope, by its broad median region
covered by about twelve ribs, by the very large ribs on its posterior wing,
and by its transverseness.

It appears to be identical with the shell described as C. aliforme by Sowerby
in the ‘ Geol. Trans.,’ but not with the original C. aliforme of the ‘ Min. Conch.’

Phillips identifies it with C. aliforme, var. y, Goldfuss ;’ but it appears to me
that that Carboniferous species is much shorter, and that the ribs on its cordiform
slope, which is much larger, are very much more numerous.

D’Orbigny re-names the species, as he considers it distinct from Phillips’s
original Yorkshire shell.” An examination of Carboniferous specimens in the
British Museum makes me think that he is certainly correct in this.

6. Conocarpium VILLMARENSE, d@’Archiac and de Vernewil, sp. Pl. II, figs. 8,
8 a—e, 9.

1842. Carpium VILLMARENSE, d’Archiac and de Verneuil. Geol. Trans., ser. 2,
vol. vi, pt. 2, p. 375, pl. xxxvi, figs. 9,9 a, 98,
10, 10 a.
1849. ConocarDIum VILLMARENSE, d’Orbigny. Prodrome, vol. i, p. 80.
1853. CaRDIUM BREVIALATUM, Sandberger. Verst. Rhein. Nassau, p. 258, pl. xxvii,
figs. 7, 7a, 7b.
1881. Conocarpium RAkuM, Barrande, Syst. Sil. Bohéme, vol. vi, pl. exev,
figs. 2, 1-10, Et. F.
1889. PLevroruyncuus VILLMARENSE, Whidborne. Geol. Mag., dec. 3, vol. vi,
p- 79.
TS NS PND NE EE
1 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 218, pl. exlii, figs. 12, ¢ (only).
2 1836, Phillips, ‘ Geol. Yorks.,’ vol. ui, p. 210, pl. v, fig. 27.

CONOCARDIUM. 29

Deseription.—Shell small, equivalve, moderately convex, suborbicular, winged
both in front and behind. Umbones small, direct, incurved, subproximate, not
prominent, situate near the median line. Hinge-line long, nearly straight, slightly
sunk below the rounded superior margin; extending in front of the umbo into a
small tubular rostrum which seems slightly tilted upwards. Anterior margin first
produced to form this rostrum, then concave for a short distance, and then
convex. Inferior margin broad and convex. Posterior margin oblique, straight,
meeting the hinge-margin at an angle of about 60°. Anterior cordiform slope
small, sharply bounded, about half the height of the shell, concave round the
produced beak in its centre, and covered by a few small, low ribs, which are
truncated superiorly by its elevated bounding-line or anterior keel, behind which
the median region is moderately and evenly convex till it reaches the indistinct
median keel, after which it sinks to form a concave hind wing. Surface of the
back ornamented by seven or eight low flat ribs, bounded by elevated threads,
and separated by similar low interspaces, which are generally bisected by a
thread ; the whole crossed by rather numerous, elevated, raised, distant, con-
centric threads, which are visible to the naked eye. Hind wing covered by about
nine low, close, rounded ridges, crossed by similar threads. Posterior edge
broadly gaping near the hinge-line.

Size.—Lenegth 10 mm., breadth 8 mm., depth 6 mm.

Locality —Lummaton. There are three small but well-preserved specimens in
my Collection, and one in the Woodwardian Museum.

ftemarks.—There is no ambiguity about this distinct and beautiful little
species. It is clearly identical with the species first described by d’Archiac and
de Verneuil. The only difference is that in the German shell the hind wing is
rather larger, the hind margin more concave, and the cordiform slope smaller ; but
these points in the English shells are subject to much variation. Mr. T. Roberts
confirms my identification.

Ican see no reason why Sandberger should have changed the name of his shell,
as he himself identifies it with d’ Archiac and de Verneuil’s species ; nor can I see
any reason for separating Barrande’s C. rarwm from it. In the figures of the
Bohemian shell the front wing is not so defined, and there seems to be no
radiating threads dividing the grooves as in the English specimens; but these
points are probably due to the fact that both of Barrande’s specimens are small
and young shells.

Affinities.—Maurer’s' version of O. Villmarense differs in having a very much
larger anterior slope, and in some other points.

1 1885, Maurer, ‘ Abhandl. Grossh. Hessisch. Geol. Landes.,’ Band i, pt. 2, p. 226, pl. ix,
figs. 19, 19 a, 20, 20a.

30 DEVONIAN FAUNA.

O. Hainense, Maurer,’ is distinguished by its larger umbo and more numerous
triangular ribs, close growth-lines, and other features.

7, CONOCARDIUM FRATER, n. sp. PI. II, figs. 10, 10 a.

Description.—Shell small, equivalve, moderately convex, suborbicular, higher
than wide, with a short hind wing. Umbones direct, incurved, rather prominent,
situate in front of the median line. MHinge-line long. Anterior margin
first produced to form the rostrum, and then gently convex. Inferior margin
rather narrow and roundly convex. Posterior margin straight and very oblique.
Anterior cordiform slope small, very narrow and concave, passing imperceptibly
into the median region. Anterior keel undeveloped. Median region rather
narrow and very convex, bearing seven low rounded ribs, alternating with a
still lower series of similar ribs, from which they are divided by linear furrows ;
the whole crossed by very numerous, regular, close striz#, which are convex
toward the umbo on the higher series of ribs, and still more numerous and
straight on the lower series. Posterior slope concave, bearing four or five almost
linear ribs. Hind wing flattish, bearing about five flat, small, close ribs.

Size.—Leneth 10 mm., breadth 10 mm., depth 7 mm.

Locality.—There is a single specimen in my Collection from Lummaton.

Remarks.—This little shell so closely resembles Conocardium Villmarense
that it is doubtful whether it is more than a variety; and this question is
the more difficult to decide as I know only a single specimen. At the same
time it distinctly differs in many of its details. It is decidedly less transverse ;
its anterior side is less convex; instead of having flat furrows it has a tendency
to a second series of rounded ribs ; and its transverse ornament is much finer and
of a different character. Under these circumstances I am inclined to treat it,
for the present, as a distinct though very closely allied species, while fully realising
that further evidence may show that it is only a variety of the last-named shell.

1 1885, Maurer, ‘ Abhand. Grossh. Hessisch. Geol. Landes.,’ Band i, pt. 2, p. 229, pl. ix,
figs. 21, 21a.

MEGALODON. ol

II. Family.—Mecatopontivm, Zittel, 1881.

1. Genus.—Mzcatopon, Sowerby, 1827.

1. MzcGatopon appreviatus, Schlotheim, sp.

1820.
1821.
1827.
1830.
1834-40.

1837.
1841.
1848.
1848.
1854.
1855.
1857.
1862.
1867.

1876.
1879.

1881.

1884.

1885.
1887.

1888.
1888.
1891.

BuUCARDITES ABBREVIATUS, Schlotheim. Peitrefact., p. 207.

— —- — Nacht. Petref., p. 63, pl. xu, fig. 4.
Mreatopon cucutiatvs, Sowerby. Min, Conch., vol. vi, p. 182, pl. dlxviii.
HippoPopIuM aBBREVIATUM, Honinghaus. Jahrb. f. Min., p. 237.
MrcaLonus cucuLtatvs, Goldfuss. Petref. Germ., vol. ii, p. 183, pl. exxxii,

figs. 8 a—d,
— — Bronn. Lethxa Geoegn., p. 91, pl. 11, figs. 4 a—d.
Mreatopon cucurtiatum, Phillips. Pal. Foss., p. 37, pl. xvii, fig. 60.
_ ELoNGATUS, F. A. Romer. Verst. Harzgeb., p. 24, pl. vi,
fig. 16.
— cucuLLaTus, Bronn. Handbuch, pt. 3, p. 709.
— — Morris. Catal. Brit. Foss., p. 209.
_— — Pictet. Paléont., vol. iii, p. 518, pl. xxix, fig. 3.
-— — Keferstein. Zeitsch. Deutsch. Geol. Gesell.,
, vol. ix, p. 160.
EUMEGALODON CUCULLATUS, Giimbel. Sitz.’Math. Nat. Class, Akademie,
Wien, Band xlv, pt. 1, p. 361.
MEGALODON cUCULLATUS, Quenstedt. Handb. Petref., ed. 2, p. 663, pl. lv,
figs. 30, 31.
= — F. Romer. Lethea Pal., pl. xxxui, figs. 1 a, 6.
_ — Nicholson. Manual Paleont., vol. i, p. 502,

fig. 368 a.

— — Zittel. Handb. Paleozool., Band ii, p. 69,
fig. 100.

— — Tryon. Struct. Conch., vol. iii, p. 207, pl. exxii,
fig. 41.

— CUCULLATUM, Phillips. Manual of Geology, pt. 2, pl. ix, fig. 9.
— CUCULLATUS, Mischer. Manuel Conch., p. 1168, fig. 829;
pl. xviii, fig. 19.
_ — Prestwich. Geology, vol. ii, p. 78, pl. v, fig. 9.
— — Etheridge. Foss. Brit., vol. i, Pal., p. 161.
— — Boehm. Bericht. Naturf. Gesell., vol. vi, pt. 2,
p. 33, figs. 1—4.

Remarks.—I have met with no example of this species from the localities now
under notice. It is, however, described both by Sowerby and by Phillips from
“ Bradley,’ which probably means that it was obtained by them from the

Wolborough Quarry.

“9

DEVONIAN FAUNA.

(rs)

Goldfuss, Bronn, and others give B. abbreviatus asa synonym for M. cucullatus,
but if this be so the former name clearly carries the priority. Schlotheim’s figures
have every appearance of being the same species as those of Goldfuss, &. The
only differences I note are that in the former the keel which encloses the escutcheon
meets halfway down the posterior side instead of at its base, so that the escutcheon
is shorter; and also that the base is only gently convex, as in Goldfuss’s figure of
the young shell, and unlike the deeply convex base of his full-grown example.

Sowerby’s and Phillips’s figures differ more considerably. They represent a
very high variety with a smaller beak, from which the front margin runs almost
straight down; but the arrangement of the hinge is similar, and there appears to
be no sufficient reason for separating them.

Keferstein regards M. elongatus, F. A. Romer, as an old and worn example of
the same species; and this view is certainly supported by the German specimens
in the British Museum.

M. Adolfi, Clarke,’ is very similar. Clarke distinguishes it by its less recurved
and swollen umbo, its less concave lunule, its straighter front margin, and its
broader and more flattened shell. It may, however, be questioned if it be more
than a variety; at all events, in these points it approaches the British form.

Il. Family.—Astartiva, Gray, 1840.
1. Genus.—Mxrcynopon, Keferstein, 1857.

Shell long, concentrically striated or smooth, with a diagonal keel extending
from the beak to the posterior margin. Ligament external, short. Hinge with a
long elevated cardinal tooth parallel to the hinge-margin, with a pit posterior to it
in the right valve, and anterior to itin the left ; and with a long and stout posterior
lateral tooth. Anterior muscular impression deep, with a smaller but deeper
impression of the foot-retractor behind it; posterior muscular impression near the
middle of the posterior margin.

This definition is almost in the words of Keferstein, Zittel, and Tryon. I am
not, however, able to understand all its points by a comparison either of our
specimens or of Goldfuss’s figures, to which Keferstein refers.

In external shape it has considerable likeness to the genus Goniophora,
Phillips, as G. Hauchicornet, Beushausen,” indicates; but that genus has no
lateral teeth.

1 1884, Clarke, ‘Neues Jahrb. f. Min.,’ Beil.-Band iu, p. 876, pl. vi, figs. 16, 17.
2 1884, Beushausen, ‘ Abhandl. Geol. Specialk. Preuss.,’ Band vi, pt. 1, p. 118, pl. iu, fig. 1.

MECYNODON. 33

1. Mucynopon cotumsBinus, Whidborne, sp. Pl. II, figs. 12—14.

? 1834-40. Mzreanopus cartnatus, Goldfuss (pars). Petref. Germ., vol. ii, p. 183,
pl. exxxii, fig. 9d (only).
1889. Mecanopon ? conumsBinus, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.— Shell equivalve, very imequilateral, long, rather narrow, trans-
verse, subquadrate or lozenge-shaped, convex. Umbones small, wide, depressed,
proximate, recurved spirally forward, overhanging the anterior point of the hinge-
margin. Hinge-margin slightly convex, about three-quarters the length of the
shell. Anterior margin very convex, receding. Antero-inferior margin convex ;
postero-inferior margin concave; inferior margin thus being sigmoidal. Posterior
margin oblique, straight. Infero-posterior point much produced, acutely angular.
Back divided by a very elevated, acute ridge, which rises at the back of the umbo,
arches round in a slightly reversed sigmoidal curve to the postero-inferior point,
and gradually becomes extremely lofty, so as to expand far beyond the rest of the
Shell, and in front of which the contour of the back is first concave, then nearly
_ straight, and then bending in rapidly to the front margin. Surface, behind this
line of greatest elevation, broadly concave, till it meets a much smaller ridge,
which arches from the back of the umbo to the postero-superior point, and thus
encloses a large, shallow, lanceolate escutcheon, bisected by the raised hinge-
margin. No lunule.

Surface covered, in front of the first ridge, with numerous (about thirty)
distant, elevated, acute, transverse, rather irregular and unequal, divaricating

threads, facing upwards, and separated by concave interspaces ; between the two
ridges with similar, but much finer, more numerous, and more regular threads ;
and on the area with a few indistinct bulges. Shell-structure massive.

Hinge of the left valve with a deep, short groove, preceding a short, large,
triangular, oblique central tooth, followed by a narrow gap containing an external
ligament, beyond which is a long, large, narrow, horizontal posterior tooth. Pedal
impression very deep and transverse. Muscular impressions rather large, shallow,
and sublunate. Pallial line slightly notched in the centre of the posterior
margin.

Size.-—Leneth 28 mm., breadth 21 mm., depth of both valves 20 mm. Another
imperfect specimen is at least twice as large.

Locality.—Chudleigh. There are three specimens in Mr. Vicary’s Collection,
two of which are in beautifuily perfect condition.

Remarks.—It is rare indeed that both the externa] and internal characters of
a Devonian shell are so well preserved as they are in these lovely fossils ; and it

VOL. II. ; B)

34. DEVONIAN FAUNA.

is disappointing to find that after all there is great perplexity in deciding its
specific position. ‘This arises in part from its great variability, which is at once
observable in our figures, and in part from its similarity to another equally
variable shell. )

It appears to me that the shell Mecynodon carinatus, Goldfuss, sp., as given by
him and other foreign authors, differs from the present species in several respects,
e.g. in the posterior concavity of the hinge-line, the greater elevation and posterior
facing of the umbo, the different shape and direction of the teeth, the contour
of the dorsal keel, and some other points. These distinctions exist still more
markedly in the shell next to be described, which we take to be a very aged
example of Goldfuss’s shell.

To perplex the question still further there are several specimens from Paffrath
in the British Museum, which, although labelled in German handwriting as M.
carinatus, agree with the present rather than with Goldfuss’s form.

The true solution might of course be that both forms belong to one
extremely variable species; but I think that, as far as our present evidence goes,
the presumption is strongly against this. For instance, we may observe that
these differences, which are as evident in small specimens, become accentuated in
very aged shells. This may be seen by comparing the figures given in our
Pl. II, figs. 14 and 15.

It is possible that the smallest of the specimens figured by Goldfuss belonged
not to his species, but to the present shell.

Affinities.—The shell figured as Megalodon carinatus by Phillips’ is totally
removed both from the present and from Goldfuss’s form.

Megalodon bipartitus, F. Romer’ is a species founded on the cast of a some-
what similar shell, which seems to differ in being longer, narrow behind, and in
having a much stronger and larger muscle-mark.

2. Mzcynopon carinatus, Goldfuss, sp. Pl. I, figs. 15, 15 a, 15 6.

1834-40. Mrcatopus carinatus, Goldfuss (pars). Petref. Germ., vol. ii, p. 183,
pl. exxxii, figs. 9 a—e, e, f (only).
1848. Mrceatopon cartnatus, Bronn. Handbuch, pt. 3, p. 709.

1853. _— _— Steininger. Geogn. Beschr. Eifel, p. 55.

1854. —_— — Morris. Catal. Brit. Foss., p. 209.

1857. Mercynopon carinatus, Keferstein. Zeitsch. Deuts. Geol. Gesell., vol. ix,
p. 158.

1 1841, Phillips, ‘ Pal. Foss.,’ p. 186, pl. lx, figs. 60* a, 0.
2 1844, I. Romer, ‘ Rhein. Uebergangsgeb.,’ p. 78, pl. ui, fig. 2.

MECYNODON. 35

1867. MzGaLopon caRrInaTus, Quenstedt. Handb. Petref., ed. 2, p. 668, pl. lv,

fig. 27.
1884. Mzecynopon carinatus, Tryon. Struct. Conch., vol. iii, p. 231, pl. exxii,
figs. 42, 43.
1888. Mzgatopon carinatus, Etheridge. Foss. Brit., vol. i, Pal., p. 161.
1890. —_ ? PROMINENS, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.— Left valve very inequilateral, long, rather narrow, transverse,
convex. Umbo prominent, proximate, recurved spirally backward, situate at the
extreme anterior point of the hinge-margin. Hinge-margin rather concave, about
three-quarters the length of the shell. Anterior margin very convex, receding.
Inferior margin nearly straight, shghtly produced and concave at the postero-
inferior point. Posterior margin slightly concave, very oblique. Back of
shell divided by a very strong, elevated, angular ridge, rising at the back of
the umbo, and arching round to the postero-inferior point in a sweeping curve,
which is concave with regard to the postero-superior point, and does not
apparently expand much beyond the rest of the shell. Contour, in front of this
line of greatest elevation, at first concave, then oblique, and then curving in per-
pendicularly to the margins ; and, in behind it, at first concave and then obliquely
flat, till it reaches a much smaller angle or upward ridge, which arches concavely
with regard to the hinge-margin from the umbo to the postero-superior point, and
thus bounds a rather large, deep, lanceolate escutcheon. No lunule.

Surface covered, in front of the first ridge, with rather numerous, irregular,
distant, elevated, acute, transverse threads, separated by concave interspaces ;
between the two ridges, with much more numerous close irregular threads or
growth-lines ; and, on the escutcheon, with a few indistinct bulges. Shell-structure
massive.

Hinge with a long, large, linear, oblique, central tooth, next to which appears a
ligamental gap, and at the posterior end a large, long, posterior tooth. Anterior
lateral teeth unseen.

Size-—Length 65 mm., breadth 33 mm., depth of single valve 20 mm.

Locality.—There is a single specimen in the Museum of Practical Geology
labelled “from Wolborough.”’

Remarks.—I cannot say that I am satisfied that the locality of this specimen
is correctly given. The matrix is very different from that usual with Wolborough
fossils. It is a soft yellowish-brown sub-oolitic rock, occasionally ferruginous.
This seems to be slightly similar to the matrix of some of the Chudleigh fossils,
but not to the generality of them. Is there any possibility of its being a German
fossil, which was placed by Mr. Godwin-Austen with his shells for reference ?

It now appears to me that this fossil is most probably an aged specimen of the
true Megalodon carinatus, Goldfuss ; for, although its shape does not quite agree

36 DEVONIAN FAUNA.

with Goldfuss’s figured specimens, the differences are such as may be accounted
for by its being a larger and more aged example. Our shell is proportionately
longer, its umbo is more prominent, and its anterior side more receding. The
hinge teeth are not very clearly seen, but on the whole they seem very similar to
those in Goldfuss’s fig. 97. Goldfuss figures several specimens of different sizes,
and it is to be observed that as their size increases their shapes approximate to
ours, which is about half as long again as_ the largest of them.

Affinities —From Mecynodon columbinus this shell is distinguished by several
characters noticed under that heading, and is, I think, certainly distinct from
that species.

2. Orper.—ASIPHONIDA, Fleming, 1828.
1. Sus-orper.—HOMOMYARIA, Zittel, 1881.
I. Family.—Triconiipa, Fleming, 1828.

1. Genus.—Protoscnizopus, de Koninck, 1885.

Under this heading de Koninck has separated the Carboniferous species of
Schizodus on account of a difference in the dentition. It is more probable that a
Devonian shell, known only by its external features, would agree with these
rather than with the more recent forms of Schizodus proper. —

1. ProroscHizopus (?) TRIGONELLUS, n. sp. PI. III, fig. 2.

Description.—Right valve large, flat, ovoid, transverse. Umbo small, acute,
anterior, oblique, subproximate, hardly incurved. Anterior margin broad,
concave under the umbo, and then convex. Inferior margin slightly convex.
Infero-posterior corner very convex. Posterior margin oblique. Contour of shell
slightly and uniformly convex on the back, rapidly rounded on the anterior and
posterior sides. Surface ornamented by close, regular, microscopic strie.
Shell-structure thin.

Size of valve-—Length 28 mm., breadth 22 mm., depth 7 mm.

Locality.—A single specimen from Lummaton is in my Collection.

Remarks.—This is a very perplexing shell, as the critical parts are obscured
or broken away. Mr. Htheridge and I came to the conclusion that it most

NUCULA. 37

probably belonged to the genus Schizodus (including Protoschizodus), as it closely
resembles shells of that genus in appearance.

Affinities.—In general shape Thetis (?) trigona, F. A. Romer,’ appears very
similar and nearly allied, but it is rather shorter, and more angulated behind.

Il. Family.—Nvcuuipa, @ Orbigny, 1848.
1. Genus.—Nucuna, Lamarck, 1801.

This genus arose in Silurian times, and is well represented in the English
Devonian. From the present localities, however, I only know a single specimen,
and that is only allocated in it on account of its external characters.

1. Nucu.a Protest, Minster. Pl. III, figs. 3, 3a.

21840. Nucuta Prorert, Minster. Beitr., pt. 3, p. 54, pl. xi, fig. 9.
1884. — sp., Clarke. Neues Jahrb. f. Min., Beil.-Band iii, p. 376, pl. vi,
figs. 10, 11.

Description.—Shell small, convex, elongate, subtrigonal, very inequilateral.
Umbo very posterior, incurved, rather large, elevated, apparently proximate and
facing backwards. Superior margin straight, long. Posterior margin nearly
straight and perpendicular, obliquely truncated below. Inferior margin mode-
rately convex. Anterior margin short and very convex. Contour of back very
convex, becoming almost perpendicular over the posterior edge, and gradually
sloping out almost flatly in front. Surface marked with a few irregularly placed
impressed growth-lines, and with more regular impressed microscopic inter-
mediate strize.

Size.—Length 19 mm., breadth 14 mm., depth of valve 6 mm. ;

Remarks.—In general shape this shell is strongly suggestive of the genus
Nucula, but its hinge-line is invisible. It seems exactly similar to Nucula
Protei, Minster, excepting that Minster’s shell is very much smaller, shows no
concentric lines, and has a rather sharper postero-inferior corner. I have
therefore regarded it as belonging to that shell.

The Nucula described by Clarke from the [berger Kalk is so hke that I think
it is identical, although its umbo may be rather larger.

1 1843, F. A. Romer, ‘ Verst. Harzgeb.,’ p. 26, pl. vi, fig. 25.

38 DEVONIAN FAUNA.

Affinities —Nucula obsoleta, Goldfuss,' is flatter, and has a more central and
perhaps less prominent umbo, and a more convex inferior margin.

Nucula tumida, Phillips,” seems a more evenly rounded shell, with a
smaller umbo.

Nucula plicata, Phillips,® as first described, is altogether a more oval shell; as
given by Dames* it is more similar, but differs in being very much smaller, in
being more produced in the infero-posterior corner, and in having the umbo
more central.

Nucula lineata, Phillips,’ has a more elevated umbo, a larger anterior side,
and very regular concentric ridges. Semenow and Moller’ refer to it some casts
which differ from the present species in the same particulars, except that the
surface-ornament is not shown.

In Nucula diluviana, Steminger,’ the umbones are less posterior.

Lutraria prisca, Goldfuss,® and L. inflata, Steininger,’ are so similar in shape
as to suggest relationship. From both shells it is, however, distinguished by
being less truncated and oblique at the postero-inferior corner.

Nucula Randalli, Hall,” while very like it, has a more ovate form, with less
posterior umbones and a less abrupt posterior side. |

N. extrema, Barrande," also approaches it, but is much flatter, and has a less
elevated and more oblique umbo.

1 1840, Miinster, ‘ Beitr.,’ pt. 3, p. 54, pl. ii, fig. 9.

2 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. 11, p. 151, pl. cxxiv, fig. 6.

3 1841, Phillips, ‘ Pal. Foss.,’ p. 38, pl. xviii, fig. 63.

4 1868, Dames, ‘ Zeitsch. Deuts. Geol. Gesell.,’ vol. xx, p. 502, pl. x, figs. 8a, 6.

5 1841, Phillips, ‘ Pal. Foss.,’ p. 39, pl. xviii, figs. 64a, a—d, and 64 6, a, 6.

6 1863, Semenow and Moller, ‘ Mél. Phys. et Chim.,’ vol. v, p. 678, pl. iv, fig. 11.

7 1853, Steininger, ‘ Geogn. Beschr. Eifel,’ p. 54, pl. iii, figs. 8 a, 4, e.

8 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 259, pl. cliii, figs. 9a, b.

9 18538, Steininger, ‘Geogn. Beschr. Eifel,’ p. 50, pl. iii, figs. 1 a, 6.

10 1885, Hall, ‘ Pal. N. Y.,’ vol. v, pt. 1, sect. 2, p. 315, pl. xlv, figs. 6—10, 16, 23, 26, 27; and
pl. xciii, figs. 1—3.

11 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pl. celxxiii, figs. 3, 1-9, Et. D.

PARALLELODON. 39

IL. Family.—Arciva, Gray, 1840.
I. Sub-family.—Arcina, H. and A. Adams, 1858.
1. Genus.—Parattetopon, Meek and Worthen, 1866.

‘The paleozoic shells ranged under this genus correspond in shape with the
Jurassic species for which Lycett founded the genus Macrodon in 1845, and only
differ by having the anterior teeth transverse instead of oblique. The two genera
are united by Zittel and by Fischer, but de Koninck doubts their identity.

Under any circumstances Lycett’s name cannot stand, as it was preoccupied
for a group of fishes by J. Miller in 1842.

1. PaRALLELODON atavus, n. sp. PI. I, figs. 1, la.

Description.— Left valve tumid, very long and narrow, almost trapezoidal.
Umbo situated almost at the anterior extremity, low, flattened, and turned
forward. Area apparently rather broad and concave. MHinge-line straight,
almost the length of the shell. Anterior margin rounded, obtuse. Inferior
margin nearly straight, slightly oblique. Posterior margin oblique above,
rounded at the postero-inferior corner. A strong angle running from the umbo
to the postero-inferior corner. Hind wing flattened. Inferior edges so convex as
to meet almost at two right angles. Surface marked with numerous fine,
parallel, well-defined, raised, and rather distant threads, following the course of
the margins and ending perpendicularly to the hinge-margin. Shell-structure
rather thick.

Size of left valve-—Length 21 mm., breadth 10 mm., depth 5 mm.

Locality.—A single valve from Wolborough is in Mr. Vicary’s Collection.

Remarks.—This shell evidently belongs to a very distinct species, but the
single specimen with which I am acquainted is insufficient to allow as complete a
definition as could be wished. ‘The anterior margin, the hinge, and the right valve
are unseen; but the general character of the shell is clear enough. It seems
probable that the anterior part of the inferior margin was somewhat gaping.

Mr. Vicary’s specimen has been labelled ‘* Sanguinolites.’ I was at first
doubtful whether to adopt this view, but the thickness of the shell-structure and
the prominence of the umbo seem to be arguments against it. On the other hand,

A() DEVONIAN FAUNA.

although the hinge cannot be seen, its general similarity to Macrodon Hirsonensis,
Lycett, and still more to numerous species of Parallelodon described by de
Konineck from the Carboniferous of Belgium, leaves little doubt that it belongs to
the latter genus.

Affinities—In Arca Michelini, dV Archiac and de Verneuil,' the nmbo is less
anterior, the posterior side shorter, and the inferior margin straighter and less
oblique.

Arca prisca, Goldfuss,’ has a more decided median depression on the back.

Sanguinolites twmidus, Phillips,’ sp., as given by de Koninck*is almost exactly the
same shape, but is less transverse, and has a smaller umbo and a broader hind wing.

The present form is much more transverse than any of the Carboniferous
species described by de Koninck except P. tenuis, de Koninck,’ which has a
much shorter hinge-line; and P. meridionalis, de Koninck,° which has a much
less regular ornament and a less prominent beak.

2. Sup-orppR.— HETEROMYARIA, Zittel, 1881.
I. Family.—Prasininm, Stoliczka, 1871.
1. Genus.—Mopio.orsis, Hall, 1847.

These shells are elongate, edentulous, transverse, subovoid, with proximate
anterior subterminal beaks, more or less straight upper margins, and large
anterior muscle-marks. They occur in the Silurian and Devonian.

The genus or sub-genus Modiomorpha, Hall, 1870, is chiefly differentiated
from the present by the possession of a single strong tooth. Beushausen and
Barrois are inclined to refer to it the Devonian species described as Modiolopsis.
As the hinge is not shown in either of the species described below, it is
impossible to decide this point with regard to them.

1 1842, d’Archiac and de Verneuil, ‘ Geol. Trans.,’ ser. 2, vol. vi, pt. 2, p. 873, pl. xxxvi, fig. 6.
2 1832-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 282, pl. cl, fig. 10.

3 1836, Phillips, ‘Geol. Yorks.,’ vol. ii, p. 209, pl. v, fig. 3.

4 1885, de Koninck, ‘Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. v, p. 81, pl. xvi, fig. 6.

5 Thid., p. 148, pl. xxiv, fig. 25.

6 Tbid., p. 158, pl. xxvi, fig. 6.

MODIOLOPSIS. Al

1. Mopiotorsis tepipa, Whidborne, sp., Pl. I, fig. 5.

1889. Crrnoponta LEPIDA, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description —Shell elongate, equivalve, flat, oblique, almond-shaped, very
inequilateral. Umbo minute, proximate, direct, anterior, situate about one fourth
the length of the shell from the anterior side. Hinge-margin straight, about
half the length of the shell. Anterior margin narrow, very convex. Inferior
margin oblique, slightly but evenly convex. Posterior margin straight and
oblique in the upper part, and perpendicularly truncated in the lower part (this
irregularity, however, being probably due to the fracture of the edges, and its
true shape being an oblique slightly arched line, becoming very convex below).
Hind wing rather concave. Pallial line simple. Anterior muscle-mark rather
large. Shell-structure apparently very thin.

Size.—Length 20 mm., breadth 11 mm., depth 6 mm.

Locality.—There is a single cast of the closed valves in the Museum of
Practical Geology from Wolborough.

Remarks.—The specimen here described is a cast in coarse saccharoid calcite,
and hence its features are very indistinct. The characters of its hinge are
obliterated, and the anterior muscular impression and the pallial line can only be
made out with great difficulty. Consequently it is impossible to decide its genus,
but its near resemblance to several Bohemian and other species of Modiolopsis
renders it most probable that it belonged either to that genus or to Modiomorpha.

Affinities —It so closely resembles Modiolopsis tenera, Barrande,’ that it
may possibly be a variety of that shell; but it seems to differ in its front and rear
margins being less blunt, and its umbo smaller and more direct.

M. plebeia, Barrande,’ has a more elevated umbo and a rather shorter hinge-
line, and is broader and shorter in front.

Some of Hall’s fieures of Modiomorpha subalata, Conrad,’ var. Chemungensis,
Hall,* accurately agree with it, and so far might be identified, but there are signs
that it was much deeper than our shell. Its muscle-mark, moreover, seems to be
much smaller.

From Pullastra modiolaris, F. A. Romer,’ itis distinguished by its more central

1 1881, Barrande, ‘Syst. Sil. Bohéme,’ vol. vi, pl. eelxxxv, figs. 1, 1-5, Et. E.
2 Thid., pl. celviii, figs. 2, 1-7, Bt. F.
8 1841, Conrad, ‘ Geol. Surv. N. Y.,’ Ann. Rept., p. 83.
4 1885, Hall, ‘ Pal. N. Y.,’ vol. v, pt. 1, sect. 2, p. 284, pl. xxxix, fig. 15; and pl. xli, figs. 5—11.
5 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 60, pl. ix, figs. 21 a, 8.
VOL. Il. 6

42 . DEVONIAN FAUNA.

umbones, its more convex and narrower anterior margin, its greater flatness,
and its probably thin test.

Modiolopsis modiolaris, Conrad,’ sp., of the Lower Silurian, is very similar in
general shape, but has a still smaller umbo and a more attenuated front margin.

Nucula Krotensis, F. A. Romer,’ and Sanguinolaria amygdalina, F. A. Romer,’
are much more regularly oval shells, and are narrower behind.

Cardiomorpha alata, Sandberger,* is also in the same general style, but has a
more produced and narrower anterior side, a straighter base, a less oblique
posterior margin, and a much less marked diagonal angle.

Sphenotus contractus, Hall,’ is also very similar in shape and in its anterior
muscular impression, but is distinguished by a depression running across the valve
to the inferior margin.

2. Mopronoprsis pouita, Whidborne, sp. Pl. IV, fig. 5.
1889. CarpioMorPHa P potira, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description —Left valve very long and narrow, convex, transversely scimitar-
shaped. Umbo minute, depressed, proximate, situated almost at the anterior
extremity. Hinge-margin nearly straight, about two-thirds the length of the
shell. Anterior margin narrow, moderately convex. Inferior margin oblique and
slightly concave. Infero-posterior corner much produced and roundly convex.
Posterior margin obliquely convex. Line of greatest convexity running straightly
down from umbo to infero-posterior corner, on each side of which the surface
slopes almost flatly down. Front wing small, diffuse, and convex. Surface smooth.
Shell-structure very thin.

Size.-—Leneth 45 mm., breadth 20 mm., depth of one valve 10 mm.

Locality.—There is a single specimen of the left valve in the Torquay Museum
in suberystalline limestone, which may have come from Barton or Lummaton.

Remarks.—This specimen, with the exception of one small portion, is a cast.
It is distinguished by its great transverseness and its strong perpendicular
anterior constriction. In general shape it bears a strong resemblance to some of
the Mesozoic forms of Modiola.

Affinities.—Modiola Kahleburgensis, F. A. Romer,’ is less constricted anteriorly,

1 1838, Conrad, ‘Ann. Geol. Rep. N. Y.,’ p. 118; and 1848, Hall, ‘Pal. N. Y.,’ vol. i, p. 294,
pl. Ixxxi, figs. 1 a—g, and pl. Ixxxu, fig. 1.

2 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 18, pl. iii, fig. 5.

3 1866, ibid., pt. 5, p. 6, pl. xxxiil, figs. 8 a, b.

+ 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 284, pl. xxvii, figs. 4, 4a, 46.

* 1885, Hall, ‘ Pal. N. Y.,’ vol. v, pt. 1, sect. 2, p. 284, pl. xxxix, fig. 15; and pl. sli, figs. 5—11.

6 1855, F. A. Romer, ‘ Beitr.,’ pt. 3, p. 11, pl. vii, fig. 3.

MODIOLOPSIS. 43

has a more convex and less oblique inferior margin, and is much more rounded
over the median keel.

In Myalina Bodana, F. A. Romer,’ the anterior side is more produced, the line
of greatest elevation less pronounced, and the upper and lower margins more
arched.

Mytilus antiquus, Goldfuss,’ is decidedly more angulated, and has a larger and
more convex anterior lobe.

Goniophora trapezoidalis, Kayser,’ is narrower behind, has a stronger and
sharper keel, a more produced and convex anterior margin, and a much less
distinct anterior depression.

Modiomorpha submissa, Barrande,* as given by Barrois,® is very similar in
contour, but is very much less transverse ; as given by Barrande it differs more
widely.

3. Mopronopsis, sp. Pl. IV, fig. 7.

Remarks.—In Mr. Vicary’s Collection is a specimen/of the posterior part of
the left valve of a shell which is too defective for description, but which does not
belong to any of the associated species. It is rather large, flattish, and decidedly
transverse. These are signs of a rounded oblique keel, or line of greatest
elevation, which vanishes before it reaches the margin. The posterior margin
is oblique and slightly convex, the postero-inferior corner rapidly rounded, and
the inferior margin oblique. The surface is ornamented by a few abrupt, steep,
step-like ridges, between each of which are seven or eight fine rounded threads or
growth-strie.

It seems somewhat similar in shape and ornament to Modiomorpha submissa,
Barrois,° and to some of the species of Modiolopsis described by Barrande, and for
that reason I have placed it provisionally in the present genus. It appears to be
a less transverse shell than Modiolopsis polita.

Locality.—W olborough.

‘ 1860, F. A. Romer, ‘ Beitr.,’ pt. 4, p. 162, pl. xxv, figs. lla, 6.

? 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 173, pl. exxx, fig. 5.

3 1885, Kayser, ‘ Jahrb. Konig. Preuss. Geol. Landes.,’ 1884, p. 19, pl. ii, fig. 4.
4 1881, Barrande, ‘ Syst. Sil. Bohéme,’ vol. vi, pl. eclviii, figs. 4, 1-7, Et. F.

5 1889, Barrois, ‘ Faun. Cale. d’Erbray,’ p. 176, pl. xii, figs. 2 a—e.

6 1889, ibid.

AA DEVONIAN FAUNA.

II. Family.—Mytitivm, Fleming, 1828.
1. Genus.—Hoprromytitus, Sandberger, 1853.

Sandberger founded this genus for equivalve, triangular, arching mussels, with
sharp umbones situated at the extreme anterior point, and with a hinge which
bears an elongated septum under the beak, behind which is a linear transverse
tooth on the right valve and a corresponding groove on the left.

The inferior parts of the shell appear to be unknown.

It occurs in the Devonian rocks.

1. Hoptomytinus crassus, Sandberger, Pl. IV, figs. 2, 2 a, 3, 3 a.

1853. HortomyrTitus crassus, Sandberger. Verst. Rhein. Nassau, p. 281,
pl. xxix, figs. 18, 13 a—e.

1884. — — Tryon. Structural Conch., vol. iii, p. 267,
pl. exxix, fig. 26.

1889. — — Whidborne. Geol. Mag., dec. 3, vol. vi, p. 78.

1891. == — Frech. Abhandl. Geol. Specialk. Preuss., Band ix,

pt. 3, p. 161, fig. 19.

_Description.—Right valve large, rather flat, recurved. Umbo small, sharp,
proximate, forming the extreme anterior point of the hinge-margin. Hinge-
margin slightly convex. Hinge consisting of a low, flattened, elongate,
triangular flap or interior lgamental area, free on the lower and _ posterior
sides, above which are three very elongate, narrow, lateral teeth, which
are nearly parallel to the margin, and are separated by broad concave grooves.
Anterior margin very concave. Line of greatest elevation arching backwards
from the umbo very near and almost parallel to the anterior margin, and rendered
angular by a flattened oblique surface in front, which is in turn bounded by
another ridge about halfway to the margin, within which the shell recedes so
as apparently to form a long, lanceolate lunule. Surface, behind the line of
ereatest elevation, sloping gently and flatly to the margins. Ornament, and
posterior and inferior regions unseen. Shell-structure very thin except on the
margins.

Size-—Large: the specimens are too defective for measurement.

Locality.—Wolborough. ‘There are three specimens in the Museum of Practical
Geology, and three specimens in the Woodwardian Museum.

MYALINA. 45

Remarks.—These fossils clearly belong to the German species described as
Hoplomytilus crassus by Sandberger. ‘They are all fragmentary, consisting only
of the umbonal portions of the shell, so that its general shape is unknown. The
same is the case with the specimens figured by Sandberger, and his description
does not throw any further light on the subject. The reason of this appears to
be the extreme tenuity of the lower part of the shell.

Under the umbo, on the anterior side, there appears to be a narrow gap
between the two margins, which was probably the aperture for a byssus.

From Sandberger’s figures the shell appears to have been very deep.

Affinities.—Myalina luna seems very similar in the general contour of its
upper part, and I once thought it might be identical. As far as can be judged,
however, it is a much flatter shell, its umbo is not actually pointed, it has a
very small convex anterior wing, and its anterior side seems to sink to the
margins with a simple steep slope instead of being doubly angulated as in the
present species.

Myalina (olim Pterinea) Goldfussiana, de Koninck,' from the Carboniferous,
presents some points of likeness, but is distinguished by its very different contour.

2. Genus.—Myatuina, de Koninck, 1842.

This genus contains mytiliform, subequivalve shells, which are generally
higher than long. The umbones are arched, sharp, terminal, and anterior. The
hinge is thick, large, and long, and bears several longitudinal cartilage-grooves.
There are two muscular impressions; the pallial line is simple, and there is no
byssal notch. The supero-posterior region seems to be frequently produced and
flattened, so as to form an indistinct rudimentary wing. It is common in the
Carboniferous and Permian, and appears to extend from the Silurian to the Trias.

1. Myanina screcia, n. sp. Pl. III, figs. 4, 4a, 5.

Description.—Valves large, short, very broad, flattish, shghtly imequivalve.
Umbo small, depressed, proximate, situate at the extreme anterior point, and
arching forward so as to project laterally beyond the rest of the shell, but not to
overhang the hinge-margin. Hinge-margin long (giving the greatest length of

1 1842-4, de Koninck, ‘ Deser. Anim. Foss.,’ p. 126, pl. iii, figs. 7 a, b.

46 DEVONIAN FAUNA.

the shell), straight except that it arches slightly downwards at the umbo.
Anterior margin very broad, slightly sigmoidal, being gently concave in the upper
part and becoming convex below. Inferior margin narrow, regularly ovate.
Posterior margin apparently gently convex, and meeting the hinge-margin at a
high angle. Lunule lancet-shaped, indistinct. Ligament external (?). Deepest
part of shell about one-third from the umbo. Line of greatest elevation running
near the anterior side from the umbo to the inferior margin, over which the surface
is strongly convex, and from which it slopes very rapidly to the margin in front,
and very gently and flatly to the margins behind. Hind wing large, indefinite,
and slightly concave. Surface smooth except for a few indistinct growth-lines.
Shell-structure thin on the back, massive near the hinge-margin, consisting of
two layers, of which the inner is dense and papyraceous, and the outer thick and
crystalline.

Size —Length 27 mm., breadth 51 mm., depth of both valves 16mm. Another
specimen is 106 mm. in breadth.

Locality—Wolborough. There are two specimens in Mr. Vicary’s Collection,
and a third (indistinct) example in the Museum of Practical Geology. :

Remarks.—This species is the largest bivalve that I have seen from the present
localities. Its hinge and interior are unknown, but its external characters are
well displayed, and so much resemble those of the numerous Carboniferous species
of Myalina given by de Koninck that I have little hesitation in referring it to
that genus. These all, however, differ from it specifically, and in most of them
the front wing is rather more definite.

The species is distinguished by its flattish subovate form, being nearly
straight above and ovate below, gently flattened rearward and steep in front, and
having a small undefined umbo at the anterior extremity.

Affinities —Mr. Roberts suggested to me that it might be the same as
Mytilus Damnoniensis, Phillips, but an examination of Phillips’s type of that
species leaves no doubt that that view cannot be sustained. The umbo of that
species is much more erect, the contour of its back 1s much more evenly convex,
and its hind wing is decidedly more definite.

The larger of Mr. Vicary’s specimens has been labelled (apparently by
Salter) “ Pterinea plana, Goldfuss, ‘ Petref.,’ pl. cix, fig. 4.” This identification
is due to a rather odd mistake. The specimen is curiously like the Mesozoic
Inoceramus nobilis, to which the above reference belongs, but is totally unlike
Pt. plana, loc. cit., pl. exix, fig. 4. The smaller and more perfect shell, however,
shows that the likeness to J. nobilis is entirely superficial.

Mytilus Ibergensis, F. A. Rémer,’ has the anterior side much steeper, the
hinge-line shorter, and the posterior margin more arched.

1 1860, F. A. Romer, ‘ Beitr.,’ pt. 4, p. 162, pl. xxv, figs. 10a, 0.

MYALINA. A7

Myalina peralata, de Koninck,' is much more triangular in shape, and has a
slightly more definite anterior wing.

2. Myauina Damnoniensis, Phillips, sp. P1. III, fig. 6.

1841. Myrinus Damyoniensis, Phillips. Pal. Foss., p. 37, pl. xvii, fig. 61.
1854. — ? — Morris. Catal. Brit. Foss., p. 214.
1889. — — Etheridge. Foss. Brit., vol. i, Pal., p. 161.
21891. Myazina BrusnavseEnt, Mrech. Abhandl. Geol. Specialk. Preuss., Band ix,
pt. 3, p. 145, pl. xvi, figs. 16, 16a.

Description.—Shell ovoid, short, very high, convex, moderately large. Umbo
anterior, prominent, proximate. Hinge-margin straight. Anterior margin very
broad, straight. Inferior and posterior margins convex. Hind wing produced,
defined, and flat. Line of greatest elevation near, and parallel to, the anterior
side, over which the shell is gently convex, gradually becoming less so behind,
and being very steep in front near the margin.

Size.—The specimens are too imperfect for measurement.

Locality—Wolborough. Phillips’s type and a second, but doubtful, specimen
are in the Museum of Practical Geology.

Remarks.—From the accidental marks there can be no doubt that the shell in
the Museum of Practical Geology is the specimen which Phillips has figured,
though his figure does not accurately represent it, but presents the appearance of
a longer and flatter shell. It is so defective as to give very few specific
characters, and on that account Phillips himself only named it provisionally. On
the other hand, he has laid stress upon the defined flattened hind wing, which
clearly distinguishes it from the other species described from these beds. The
second specimen in the museum is still more defective, and can only be doubtfully
referred to the same species.

M. Beushauseni, Frech, seems to correspond almost exactly in shape. It has,
however, a delicate surface ornamentation, which Phillips’s specimen, perhaps
from its state of preservation, does not show.

Affinities—From Myalina egregia it differs by the definite angle which marks
off the hind wing, by its much less recurved umbo, by its more evenly convex
back, and probably by its greater width in the inferior regions.

Avicula obsoleta, Goldfuss,” seems to present a somewhat similar appearance in
the relations of the wing to the rest of the shell. It is, however, much more
transverse, and its umbo is less anterior.

1 1885, de Koninck, ‘ Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. 5, p. 172, pl. xxix, fig. 5.
2 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 125, pl. exvi, figs. La, b.

AS DEVONIAN FAUNA.

3. Myatina stutta, Whidborne, sp. Pl. III, fig. 8.

1889. Myritus stunrus, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description —Right valve rather higher than long, nearly semicircular, very
convex. Umbo rather large, recurved, compressed, proximate, situate at the
anterior extremity of the upper margin. Hinge-margin straight, almost as long
as the shell. Front margin very broad, straight. Inferior and posterior margins
regularly convex. Hind wing rather large, indistinct, and concave. Line of
greatest elevation close to and parallel with the front margin; the surface being
very convex over it, becoming gradually less convex in rear of it, and sinking
almost perpendicularly to the margin in front of it. Surface covered with
numerous close, elevated, regular, transverse threads, and two or three stronger
erowth-lines.

Size.-—Length 22 mm., breadth 18 mm., depth of single valve 8 mm.

Locality.—There is a single specimen from Wolborough in the Museum of
Practical Geology.

Remarks.—This fossil is distinguished from the species that accompany it by
its short, almost semicircular shape, its great convexity, and its strong, numerous,
and regular surface-markings. It is in a rather poor state of preservation, its
shape being obscured by rock, and its surface granulated by the coarseness of the
matrix,-besides being decorticated in the manner characteristic at Wolborough.
It is possible that it bore radiating as well as transverse threads, but it is difficult
to say how far these marks are natural or due merely to fossilization.

Affinities.—Two poor specimens of Myalina ornata’ in the British Museum,
from Winterberg, seem very similar in shape and ornament, but judging from
Romer’s description that species was much higher and sharper above.

From Myalina egregia it differs in its much greater convexity, its narrower and
more concave hind wing, and in other particulars.

Modiola amygdalina, Phillips,” is more coarsely ribbed and less abruptly
truncated on the anterior side.

4, MYALINA LUNA, n. sp. Pl. IV, fig. 1.
Description.—Left valve long, lunate, flattish. Umbo very small, depressed,
situate at the anterior point of the hinge-margin, bent forward. Hinge long,

1 1860, F. A. Romer, ‘ Beitr.,’ pt. 4, p. 162, pl. xxv, figs. 12 a, b.
2 1841, Phillips, ‘ Pal. Foss.,’ p. 38, pl. xvii, figs. 62 a—e.

MYALINA. 49

almost straight. Front wing very small, convex. Anterior margin very long and
very concave. Antero-inferior corner apparently so rapidly rounded as to be
almost angular. Posterior and inferior margins continuously and regularly
convex. Line of highest elevation arching round from the umbo to the antero-
inferior corner, so as to be nearly parallel to the anterior margin ; the contour being
rapidly convex over this line, spreading out flatly behind it to the margins, and
sinking rapidly in front of it to the anterior margin. Surface marked only with a
few very indistinct growth-lines and minute intermediate striz. Shell-structure
probably very thin.

Size.—Length 37 mm., breadth 43 mm., depth of one valve about 8 mm.

Locality.—A single specimen from Lummaton is in my Collection.

Remarks.—Although much of this specimen is hidden, there is no doubt about
its shape and character. Its highly lunate shape at once distinguishes it from
every other species I know.

5. Myatina prnnoipes, Whidborne, sp. Pl. IV, fig. 4.
1889. Myrintus pinnorpEs, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.—Right valve large, triangular, oblique, recurved. Umbo small,
acute, proximate, situated at the anterior point, and facing anteriorly. Hinge-
margin long, slightly convex. Anterior margin very broad, oblique, and slightly
concave. Posterior and inferior margins convex. Contour of back flattish,
oblique, tending to form an indistinct wing behind; deepest near the front, where
it curves rather suddenly, and becomes nearly perpendicular to the anterior
margin; marked in the centre by a slight, shallow, linear depression, which runs
from behind the umbo to the postero-inferior part of the shell. Surface smooth.
Shell-structure papyraceous as far as seen, but probably its outer layer is
entirely absent.

Approximate size.— Length 45 mm., height 60 mm., depth of one valve 7 mm.

Locality.—There is a single specimen from Wolborough in Mr. Vicary’s
Collection.

Remarks.—This specimen is almost entirely a cast, and its characters cannot
be very distinctly made out. The shell on the parts where it remains is very thin,
but it seems most likely that it is only the inner layer, and that the outer layer
has entirely disappeared. Behind the umbo there is a depression which appears
to indicate a thickening of the hinge at this point.

Affinities. —This is a much less arcuate shell than Myalina lina.

It appears less elongate than Mytilus uncinatus, Hichwald,' and has a less
arched umbo.

1 1860, Eichwald, ‘ Letha Rossica,’ p. 981, pl. xxxviii, fig. 7 a, 0.
VOL, II. vl

50 DEVONIAN FAUNA.

Mytilus priscus, Goldfuss,' is straighter posteriorly and narrower.
Mytilarca Canadensis, Billings,” and Cardiomorpha mytiloidea, F. A. Romer,”
are much deeper shells, with more acute umbones, and straight anterior sides.

II. Family.—Avicutipa, d Orbigny, 1843.
I. Sub-family.—Amponyouina, Miller.
1. Genus.—GosszLetia, Barrois, 1881.*

Shell equivalve, inequilateral, gibbous, oblique; greatest thickness along a
line near the front margin dividing the shell into two regions, of which the
posterior forms an obtuse wing, while the anterior is short and steep. Beaks
prominent, not recurved, facing forward. Surface marked with numerous fine
growth-striz. Hinge with a ridge running backwards, on each side of which is a
grooved ligamental area. Cardinal teeth three.

This genus has been deseribed from the Devonian of Spain and America.

1. GossELETtA (?) sp. Pl. IV, figs. 6, 6 a.

Deseription.—Lower part of left valve of moderate size. Anterior margin
oblique, straight. Inferior margin short, very convex. Posterior margin nearly
straight Back divided by a rounded angle of greatest elevation running near and
parallel to the front margin, before which the shell is steep, and behind which it is
obliquely flattened. Surface covered with very fine, distant, minute, regular,
concentric lines.

Localitya—Lummaton. <A single fragmentary specimen is in my Collection.

Remarks.—The only specimen I know is too fragmentary for anything like a
full description, as the umbo, hinge, and upper part of the shell is entirely wanting.
The part, however, which remains falls well within the limits of Barrois’s genus,
and so nearly resembles the American species G. triquetra, Conrad,’ sp., both in
shape and ornament as to render it most probable that this is its true position.
Specifically, however, I think it differs from the American form, as the base is
more evenly rounded, and it seems a wider shell.

1 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 284, pl. cl, fig. 18.
2 1874, Billings, ‘ Paleozoic Fossils,’ vol. ii, pt. 1, p. 52, pl. iv, figs. 2, 2 a.
3 1860, F. A. Romer, ‘ Beitr.,’ pt. 4, p. 163, pl. xxv, figs. 14 a, b.
4 1881, Barrois, ‘Ann. Soc. Géol. Nord,’ vol. viii, p. 176.
5 1838, Conrad, ‘Geol. Surv. N. Y. Ann. Rept.,’ p. 116; and 1885, Hall, ‘Pal. N. Y.,’ vol. vy,
pt. 1, sect. 1, p. 265, pl. xxxi, figs. 9—17 ; and pl. Ixxxvii, fig. 12.

MYTILARCA. 51

2. Genus.—Mytitarca, Hall, 1870.

This genus contains mytiliform shells with sharp terminal umbones, straight
hinge-lines, and straight perpendicular anterior margins. The hinge has two or
three strong cardinal teeth, and is obliquely striated behind. It belongs to the
Devonian age.

Whether the shell next to be described belongs to this genus must remain
doubtful for the present, as its hinge is unseen. I have provisionally placed it
here on account of its great similarity in general shape to some of the other
species referred to the same genus by different authors. It may, however, prove
to be a Mytilus or Myalina.

1. Myritarca (?) Rosertsir, Whidborne, sp. Pl. III, figs. 7, 7 a.
1889. Mytitus Ropurrsit, Whidborne. Geol. Mag,, dec. 3, vol. vi, p. 79.

Description.—Shell almond-shaped, rather large, very high, convex. Umbo
prominent, highly incurved, proximate, anteriorly truncated, slightly turned
forward. Hinge-margin short, oblique, slightly curved. Anterior margin very
broad, straight, and perpendicular, having a long linear slit for the byssus under
the umbo. Posterior margin slightly convex. Inferior margin probably roundly
convex. Hind wing small, concave, and very narrow. Line of greatest elevation
running from the umbo parallel with and close to the front margin; the contour
of the shell being gently convex over and behind it, and perpendicular and flat
in front of it. Surface and hinge unseen.

Size of double shell—Length 20 mm., breadth about 35 mm., depth 16 mm.

Locality—Wolborough. There is a specimen in Mr. Vicary’s Collection, and
another in the Museum of Practical Geology.

Remarks.—This shell is distinguished among other features by its straight,
flat, anterior side, its narrow, concave hind wing, and its deep, incurved umbones.
Its greatest depth is very high up and near the umbo.

Affinities.—It bears a general external resemblance to Myalina crassa, Sand-
berger.’ Mr. Roberts, however, does not think that it ought to be placed with
that species. Thereis a little ambiguity in Sandberger’s drawing which makes the
exact shape of his shell uncertain ; but it appears to have been much more evenly
convex, and more acute and flattened above, and to have had a sharper umbo than
the present species.

1 1858, Sandberger ‘ Verst. Rhein. Nassau,’ p. 281, pl. xxix, figs. 12, 12 a.

52 DEVONIAN FAUNA.

From the type specimen of Mytilus Damnoniensis, Phillips, this species differs
by its very narrow and concave hind wing.

Mytilus dimidiatus, Goldfuss, sp.,1 and Ferd. Rémer,’ is less ovoid inferiorly,
and less produced in the postero-superior region.

Mytilus intwmescens, F. A. Rémer,® is also very similar, but as seen in a
German example in the British Museum is a broader and much deeper shell, with
a longer umbo. Its back appears to be more evenly convex, and the greatest
depth is much nearer the inferior margin.

Myalina ornata, F. A. Rémer,* and Cardiomorpha mytiloides, F. A. Romer,’
are both more decidedly cuneiform shells.

Mytilarca witida, Billings,’ is exceedingly similar in general form. Its umbo
seems larger and more prominent, its anterior side is concave near the beak, and
there are several other features which show it to be distinct.

Mytilus pygmeus, Goldfuss,’ of the Mountain-limestone, is a smalier, broader,
and much less angulated shell.

Mytilarca gibbosa, Hall,*® is also extremely like. It chiefly differs in having a
more rounded and shorter umbo, and a shorter and less oblique hinge-line.

Myalina solida, Maurer,’ is rather longer, and not so deep above.

3. Genus.—Puietaomytitus, Hall, 1883.

This genus is said to differ from Mytilarca im its erect form, its transverse
and shorter hinge-line, the absence of teeth, and its non-truncate anterior side.

1. PLETHOMYTILUS RETORTUS, n. sp. PI. V, fig. 1.

Description.—Left valve rather small, short, broad, ovoid, direct, flattish.
Umbo small, acute, elevated, proximate, compressed, arching rather forward, and
situate at the anterior extremity. Hinge-margin apparently short and straight.

1 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 284, pl. clx, figs. 16 a, 8.

2 1876, F. Romer, ‘ Lethea Pal.,’ pl. xxix, figs. 3 a, b.

3 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 32, pl. v, fig. 1; and 1891, Frech, ‘ Abhandl. Geol.
Specialk. Preuss,’ Band ix, pt. 3, p. 156, pl. xvii, figs. 16—16 0.

4 1860, ibid., pt. 4, p. 162, pl. xxv, figs. 12a, b.

> Ibid., p. 163, pl. xxv, figs. lla, 6.

6 1874, Billings, ‘ Paleozoic Fossils,’ vol. ii, pt. 1, p. 53, figs. 22, 23.

7 1834-40, Goldfuss, ‘ Petref. Germ.,’ vol. ii, p. 168, pl. exxviii, figs. 6 a, b.

8 1885, Hall, ‘ Pal. N. Y.,’ vol. v, pt. 1, sect. 1, p. 262, pl. xxxiii, fig. 20; pl. Ixxxvii, fig. 7.

® 1886, Maurer, ‘Fauna Rechtsrhein. Unterdevon., p. 18; and 1891, Frech, ‘Abhandl. Geol.
Specialk. Preuss,’ Band ix, pt. 8, p. 143, fig, 15.

POSIDONOMYA. 53

Anterior side very broad and nearly straight. Inferior margin broad and convex.
Posterior margin gently convex. Contour steep on the anterior side, very flat
elsewhere. Posterior wing small, short, broad, triangular, flat, defined by a
depression bounding the rear of the umbo. Surface marked with numerous
minute, distant, irregular strie or growth-lines. Shell-structure thin.

Size of single valve-—Length 20 mm., breadth 26 mm., depth 5 mm.

Localityi—Lummaton. <A single specimen is in my Collection.

Remarks.—The evidence afforded by this specimen is far from satisfactory.
The shell appears to be distinguished by its direct ovoid form, which is broader in
the lower part, its flatness, its broad low umbo which arches forward and is bounded
on each side by steep lines, and its small triangular hind wing, which is right-
angled and isosceles. Thus it seems to be distinctive, and is certainly unlike any
of the species which accompany it.

Affinities —It appears to be very similar in general shape to Mytilarca
(Plethomytilus) oviformis, Hall,’ but to be a shorter and flatter shell, with a less
incurved umbo.

Il. Sub-family.—Avicurina, Stoliczka, 1871.
1. Genus.—Postponomya, Bronn, 1837.

This genus extends from the Silurian to the Trias, but is especially charac-
teristic of the Culm, and appears rare in the Devonian. It is, therefore,
interesting to find it represented in the present beds. The species described
below appears to belong to Posidonomya as restricted by de Koninck in 1887,
who separated many of its forms under the name of Posidoniella.

1. Postponomya optonea, Trenkner, sp. Pl. IV, fig. 8.

1867. AvrovuLa oBLoNGA, Trenkner. Paliont. Novit., pt. 1, p. 22, pl. iii, fig. 48.
1889. Postponomya LaTERALIs, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 78.

Description.—Shell rather small, direct, semioval, much higher than long,
shehtly convex. Umbo small, low, sharp, slightly twisted anteriorly, apparently
not elevated above the hinge-line. Hinge-line apparently straight, and equal
to the length of shell. Anterior and posterior margins very broad, probably
slightly sinuous, and meeting the hinge-margin at high angles. Inferior margin

1 1884, Hall, ‘Pal. N. Y.,’ vol. v, pt. 1, sect. 1, p. 255, pl. xxxi, figs. 1—8 ; and pl. Ixxxvii, fig. 8.

54. DEVONIAN FAUNA.

short and roundly convex. Contour of back gently convex horizontally, almost
straight perpendicularly. Anterior and posterior wings broad, triangular, flat,
defined by indistinct depressions on each side of the umbo, which meet the
margins about halfway down. Surface covered by seven or eight very much
elevated, sharp, triangular, foliaceous ridges, separated by broad, concave inter-
spaces, and becoming much larger and more distant as they approach the margins.

Size-—Length about 14 mm., breadth about 21 mm.

Locality.—There is a single specimen from Wolborough in the Torquay
Museum, and two from the same locality in Mr. Vicary’s Collection.

Remarks.— These shells are mm poor condition, and their surface is decayed.
They are distinguished by their few and very elevated ridges, their very central
umbones, their slight obliquity, and, as far as can be judged, their wide straight
hinge-lines and angular wings. They appear so exactly to correspond with
Avicula oblonga of Trenkner that I have no hesitation in referring them to
that species.

Affinities—Phillips' figures two young specimens of Posidonomya lateralis,
Sowerby,” from the Culm, which resemble ours in the strength and fewness of the
ridges ; but they seem to be more oblique, to be more rounded superiorly, and to
have less central umbones. Sowerby’s species as originally described is clearly
distinct, as these differences are more clearly seen in it, and the ridges are,
moreover, much more numerous.

Posidonomya (?) elongata, F. A. Romer,’ seems extremely similar as far as can
be judged from its very slight description, but it differs in being very much smaller,
higher, and more oblique, and therefore is not, I think, specifically identical.

F. A. Romer* regards P. lateralis, Sow., as a variety of P. Becheri, Bronn,°
and the figure which he gives of it differs from our shells in being much wider and
having much finer ornament.

Tryon’s® figure of P. Bechert is rather similar in shape, but is more oblique
and has finer ridges.

Trenkner compares his A. oblonga with Avicula (Leiopteria) Benedeniana,
de Koninck,’ but that shell differs from it in many particulars, generic as well
as specific. |

The ridges in Avicula vasta, Trenkner,* are very much weaker.

1 1841, Phillips, ‘ Pal. Foss.,’ p. 45, pl. xx, figs. 74a, b.

2 1840, Sowerby, ‘ Geol. Trans.,’ ser. 2, vol. v, pt. 3, pl. lii, fig. 1.

3 1850, F. A. Romer, ‘ Beitr.,’ pt. 1, p. 13, pl. iii, fig. 2.

4 1843, F. A. Romer, ‘ Verst. Harzgeb.,’ p. 21, pl. vi, fig. 1 d.

5 1828, Bronn, ‘ Jahrb.,’ p. 262, pl. ii, figs. 1—4.

6 1884, Tryon, ‘Struct. Conch.,’ vol. iii, p. 274, pl. exxx, fig. 46.

7 1885, de Koninck, ‘Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. 5, p. 194, pl. xxx, fig. 19.
8 1868, Trenkner, ‘ Paliiont. Novitat.,’ pt. 2, p. 18, pl. x, fig. 11.

RUTOTIA. 55

2, Genus.—Rvurotia, de Koninck, 1885.

These shells are described as smooth, oval or suborbicular, inequilateral,
inequivalve, with an elevated and prominent umbo, undefined ears, a short
anterior and obliquely prolonged posterior side, smooth or slightly striated
surface, and a short, straight, linear, edentulous hinge.

The genus was described from Carboniferous beds, but it seems to me
that some foreign Devonian shells, referred to Inoceramus and Posidonomya, may
belong to it.

It is distinguished from Posidonomya by its smoothness and its prominent
elevated umbo.

1. Ruroria xELuiprica, Whidborne, sp. Pl. IV, figs. 9, 9a, 10; and Pl. V,
figs. 2—9.

1889. Myatina ELLiIprica, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79.

Description.—Shell large, ovoid, convex, broader than long, oblique, rath
inequilateral. Umbo prominent, incurved, rounded, sharp at the point, tending
forward but facing slightly backward, situated nearly in the centre of the upper
margin. Hinge-margin short, apparently excavate behind the umbo. Lunule
small, deep, and indefinite. Anterior margin broadly and obliquely convex.
Inferior margin short and very convex. Posterior margin gently convex. Contour
of back roundly convex in the central parts, becoming steeper behind so as to be
sometimes almost perpendicular to the posterior edge, and flattening out to the
inferior and anterior margins, forming a small, slightly concave, undefined wing
about the supero-anterior corner. Hinge unseen. Surface smooth, with only a
few very indistinct lines of growth. Shell-structure very thin.

Size of single valves.—Length 32 mm., breadth 40 mm., depth i2 mm.; or
length 35 mm., breadth 40 mm., depth 10 mm.

Localities.—From Lummaton there are thirteen specimens in my Collection,
and one in the Woodwardian Museum. From Wolborough there are six in
Mr. Vicary’s Collection/and one in the Museum of Practical Geology.

Remarks.—This is a very variable species, with few distinctive characters. The
variation is chiefly seen in the width, the obliquity, the convexity, and the contour
of the postero-superior part, which is usually steep but occasionally somewhat
expanded. It would be easy to regard several of the shapes as specifically distinct
if they occurred alone; but, on comparing a number of specimens together, it is

56 DEVONIAN FAUNA.

seen that hardly two can be found alike, and that they pass one into another by
imperceptible differences. It is one of the commonest bivalves at Lummaton.

It seems to have been usually mistaken for and labelled Megalodon cucullatus,
Sowerby, but from that shell it is totally distinct. Mr. Roberts and I carefully
compared it with the figures and descriptions of the latter species given by
Sowerby, Goldfuss, and Phillips, and with German specimens in the Woodwardian
Museum, and we found them to be in every case utterly unlike, and not even
to belong to the same genus.

On my showing it to Mr. R. Etheridge, F.R.S., he suggested Cardiomorpha as
possibly its genus ; but the numerous species figured by de Koninck seem to show
that it differs essentially from that genus, especially in the much less erect and
simple character of its umbo. On the other hand, as far as can be judged from
external characters, it meets all the requirements of the genus Rutotia ; and one of
the Carboniferous species, Rutotia ovalis, de Koninck,' comes so close that there
is great difficulty in differentiating it, considering the great variability of our shell.
However, de Koninck’s two figures are much smaller than our full-grown shells,
while they are very unlike our young specimens of the same size. Their anterior
wing also seems to be higher and more angular than usual, and their umbones
rather blunter. On the whole, though they ultimately may prove identical, the
Belgian evidence seems too slight at present to justify us in uniting shells which
come from different formations.

Affinities — Unio castor, Kichwald,’ seems to be a deeper and narrower shell,
with a more arched and incurved umbo and narrower wings.

Myalina tenwistriata, Sandberger,’ closely resembles young specimens in shape,
but is distinctly radiated.

Pterinea arduensis, Steiminger,* has definite front and hind wings, and numer-
ous concentric striz. .

Inoceramus regularis, Minster,’ which is the same as Posidonomya regularis,
Geinitz,° is larger and flatter, and has some concentric striw and less distinct
wing's.

Inoceramus semistriatus, Minster,’ bears radiations on the anterior side.

Posidonomya (2) grandis, Mimster,® is an imperfectly described species which,
though much larger, has some likeness to the more equilateral varieties of our
shell, but does not show sufficient characters for full comparision.

1 1885, de Koninck, ‘ Ann. Mus. Roy. H. N. Belg.,’ vol. ix, pt. v, p. 200, pl. xxii, figs. 36, 40.

2 1860, Hichwald, ‘ Lethea Rossica, p. 1003, pl. xxxix, figs. 20 a, 0d.

’ 1853, Sandberger, ‘ Verst. Rhein. Nassau,’ p. 280, pl. xxix, figs. 10, 10 a.

4 18538, Steininger, ‘Geogn. Beschreib. Eifel,’ p. 55, pl. ii, figs. 8—11.

1840, Minster, ‘ Beitr.,’ pt. 3, p. 48, pl. x, figs. La, d.

1858, Geinitz, ‘ Verst. Grauw. Sachsen,’ pt. 2, p. 51, pl. xiii, figs. 3, 3a, 4, 4a.
1840, Minster, ‘ Beitr.,’ pt. 3, p. 49, pl. x, figs. 7 a, b.

8 Tbid., p. 50, pl. x, fig. 10.

“1 for) or

Sut

fe
A)

PLATE I.

(The separate lines indicate the length of the specimens.)

PARALLELODON ATAVUS, n. sp. (Page 39.)
Fia.

1. Left valve, injured at the sides but showing the ornament. 1 a, upper view. Wolborough.
Vicary Collection.

ALLORISMA DUBIUM, Whidborne, sp. (Page 4.)

2. Lett valve, retaining a fragment of the shell. 2a, upper view. Wolborough. Vicary Collection.
3. A larger but very defective specimen, in which the anterior side is more produced. Lummaton.
My Collection.

EpMONDIA C@LATA, n. sp. (Page 2.)

4. Right valve, injured in front. Wolborough. Vicary Collection.

Moptotopsis LePIpA, Whidborne, sp. (Page 41.)

5. Cast of a specimen with the valves in contact. Wolborough. Museum of Practical Geology.

CYPRICARDINIA SCALARIS, Phillips, sp. (Page 5.)

6. Elongate specimen. 6 a, upper view. 6 6, anterior view. Lummaton (?). Torquay Museum.

7. Another elongate specimen, with very prominent beak and strong sinus. Lummaton. My
Collection.

8. Less transverse specimen, with smaller umbo and more evenly convex anterior side. Lummaton.
My Collection.

CYPRICARDINIA STRIATISSIMA, n. sp. (Page 9.)

9. Left valve, somewhat worn, and slightly fractured. 94a, upper view. Wolborough. Vicary
Collection.

. 10. Right valve, obscured by matrix in front, and with rather coarser strie. Barton. Lee Collection.

CYPRICARDINIA RETICULATA, Phillips, sp. (Page 11.)

11. Right valve, showing the ornamentation very clearly, but a little defective at the infero-posterior
region. lla, upper view. Lummaton. My Collection.

12. Closed shell, with surface so much worn that the radiating strie are unseen. Wolborough.
Museum of Practical Geology.

13. Right valve, similar in shape, but with rather closer radiating striwe. Lummaton (?), Torquay
Museum.

CYPRICARDINIA ENSIFORMIS, Whidborne, sp. (Page 13.)

14, Left valve, wanting umbo and perhaps rather flattened. Wolborough (?). Torquay Museum.
15. Left valve, very defective. Lummaton. My Collection.
16. Another left valve, very nearly perfect. Barton. Lee Collection, British Museum.

ConoOcARDIUM CLATHRATUM, d’Orbigny. (Page 18.)

17. Large specimen with the median region well defined. 17 a, anterior view. Lummaton. My
Collection.

18. Left valve of another specimen. 18 a, portion of surface enlarged. Lummaton. My Col-
lection. ;

19. A more transverse specimen, injured below. 19 a, upper view. 19 8, portion of surface of
anterior slope enlarged. 19 ¢, portion of surface of posterior side enlarged. Lummaton.
My Collection.

20. One of Phillips’s figured specimens, which is very much worn and injured, but shows the shape of
the rostrum. Wolborough. Museum of Practical Geology.

A.Gawan del. et lith. Mintern Bros. imp

PLATE II.

CoNOCARDIUM CLATHRATUM, d@’Orbigny. (Page 18.)

Fra.

ie
2.
3.

10.

11.

12.
13.
14.

15.

Large and flattish specimen. 1 a, anterior view. 1 6, upper view. 1 c¢, portion of surface
enlarged. (The strie are here represented too close.) Lummaton or Barton. Torquay Museum.

Left valve of a very broad specimen, with very strongly marked median keel, and very coarse
transverse striz. 2a, portion of surface enlarged. Barton. Torquay Museum.

A similar but smaller and less perfect specimen, Uummaton. British Museum.

ConocaRrDIUM PUGNANS, Whidborne, sp. (Page 24.)

. An almost perfect specimen. 4 a, anterior view. 4 b, upper view. 4 ce, portion of posterior

side enlarged, showing the very fine strie. Lummaton. My Collection.

. Another and more transverse specimen. 5 a, anterior view. Lummaton. My Collection.

ConocarpIuM HystERICUM, Schlotheim, sp. (Page 26.)

. Specimen showing the large smooth ribs and wide posterior gape. 6 a, upper view, showing the

great depth of the shell. 6 6, anterior view. Chudleigh. Vicary Collection.

. Another worn but very globose specimen, showing the convex hinge-margin. This specimen is

almost exactly like Schlotheim’s original figure. 7 a, upper view. Chudleigh. Vicary
Collection.

ConocaRrpIuM VILLMARENSE, d’ Archiac and de Verneuil, sp. (Page 28.)

. Large transverse specimen. 8 a, anterior view, showing the small and defined concave anterior

slope. 8 6, upper view. 8 ¢, portion of the surface of the back enlarged. Lummaton. My
Collection.

. Smaller and less transverse specimen. Lummaton. My Collection.

CoNOCARDIUM FRATER, n. sp. (Page 30.)

Specimen showing the very fine ornament, the large anterior slope, and prominent umbones.
10 a, portion of surface of dorsal region enlarged. Lummaton. My Collection.

Isocarpra CRoKERI, n. sp. (Page 15.)

Right valve, showing its large and convex anterior side. 11 a, upper view, showing the lanceolate
truncated escutcheon. Wolborough. Vicary Collection.

MEcyNnopon conuMBINUS, Whidborne, sp. (Page 33.)

Perfect specimen with very lofty keel. 12a, upper view, showing the posterior elongation of
the keel. Chudleigh. Vicary Collection.

Left valve of another perfect specimen. 13 a, inner view, showing hinge, pedal impression,
posterior muscle-mark, and pallial line. Chudleigh. Vicary Collection.

Much larger but less perfect specimen, showing the umbo overhanging the anterior side. Chud-
leigh. Vicary Collection.

Mecynopon carinatvs, Goldfuss, sp. (Page 34.)

Left valve of a very aged specimen, showing the contour of the keel. 15 a, upper view, showing
the very great concavity of the escutcheon. 15 6, inner view, showing the concave hinge-line.
“ Wolborough ” (?). Museum of Practical Geology.

mies

@
a

imp

Mintern Bros.

A. Gawan.del. et lith.

PLATE III.

GoNnrIoPHORA OBLIQUA, Whidborne, sp. (Page 16.)
Fria.

1. Left valve, showing the lofty keel arching downwards. 1 a, inner view,
showing the umbo and the hinge. 1 b, oblique view, showing the ornamen-
tation. (Phillips’s figure of his type seems to have been drawn in this
aspect.) Wolborough. Museum of Practical Geology.

PROTOSCHIZODUS P TRIGONELLUS, n. sp. (Page 36.)

2. Right valve, slightly injured on the margins. Lummaton. My Collection.

Nucuna Provet, Miinster. (Page 37.)
3. Left valve, showing the ornament. 3 a, upper view. Lummaton. My
Collection. ;
MYALINA EGREGIA, n. sp. (Page 45.)

4. Very perfect specimen retaining the shell, and only injured at the supero-
posterior corner. 4 a, anterior view. Wolborough. Vicary Collection.

5. Very large but imperfect specimen, showing the thickness of the shell near
the umbo. Wolborough. Vicary Collection.

Myautna Damnontensis, Phillips, sp. (Page 47.)
6 Phillips’s type specimen, showing the definite posterior wing. Wolborough.
Museum of Practical Geology.

Myrtitarca (?) Rosertsu, Whidborne, sp. (Page 51.)

7. Specimen showing the narrow posterior wing. 7 a, posterior view, showing
the shape of the umbones. Wolborough. Vicary Collection.

Myatina stutta, Whidborne, sp. (Page 48.)

8. Right valve, showing the surface-ornament though rather worn. Wol-
borough. Museum of Practical Geology.

WO eal

A. Gawan. del. et: lith.

Fra.
1.

6.

10.

11.

PLATE IV.
MYALINA LUNA, n. sp. (Page 48.)

Left valve, showing the small subterminal umbo and the concave anterior side,
Lummaton. My Collection.

Hortomytitus crassus, Sandberger. (Page 44.)

. Upper portion of a flattish right valve apparently with surface much worn,

showing the acute terminal umbo. 2 a, inner view. Wolborough.
Museum of Practical Geology.

. Inner view of another, much worn specimen. 3 a, anterior view. Wol-

borough. Woodwardian Museum.

Myatina Pinnoipes, Whidborne, sp. (Page 49.)

. Internal cast of right valve, showing median depression. Wolborough.

Vicary Collection.

Moptotorsts pouita, Whidborne, sp. (Page 42.)

. Left valve, showing the small anterior lobe and the great transverseness of

the shell. Barton (?). Torquay Museum.

GossELETia (?), sp. (Page 50.)

Portion of right valve, very deep anteriorly. 6 a, portion of surface x 3.
Lummaton. My Collection.

Moptonoprsis, sp. (Page 43.)

. Posterior part of a very transverse left valve, showing ornamentation.

Wolborough. Vicary Collection.

Postponomya oBLONGA, Trenkner, sp. (Page 53.) |

. Right valve, showing the small central umbo, the flat triangular wings, and

the distant acute ridges. Wolborough. Torquay Museum.

Rorotra etirprica, Whidborne, sp. (Page 55.)

. Right valve of a small broad specimen. 9 a, anterior view. Lummaton.

My Collection.
Left valve of another small specimen. Lummaton. My Collection.

PTERINEA BELLULA, Whidborne. (Page 57.)

Left valve of a defective specimen, partially retaining the shell. Wolborough.
Museum of Practical Geology.

EAE IV;

A.Gawan del.et lith. M

Fie.

1.

bo

PLATE V.
PLETHOMYTILUS RETORTUS, n. Sp. (Page 52.)

Specimen showing the expanded wing and recurved umbo. Lummaton. My
Collection.

Ruvoria evuiptica, Whidborne, sp. (Page 55.)

. Left valve with very much expanded front wing. 2 a, posterior view.

Lummaton. My Collection.

. Imperfect right valve of a very broad specimen.. Wolborough. Museum of

Practical Geology.

. Right valve of a flat shell with expanded front wing and very oblique umbo

4a, posterior view. Lummaton. My Collection.

. Right valve of a flat shell with very expanded front wing. Wolborough,

Vicary Collection.

. Left valve of a convex shell with nearly equal wings. Lummaton. My

Collection.

. Left valve of a convex shell with truncated anterior side. 7 a, upper view.

Lummaton. My Collection.

. Left valve of a rather flat and transverse shell with truncated anterior side.

8 a, posterior view. Lummaton. My Collection.

. Left valve of a broad convex shell with truncated anterior side. 9 a, anterior

view. Wolborough. Vicary Collection.

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