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Ayo ote N. OR eal Ss

OF THE

CHARACTERS

OF THE

CARBONIFEROUS LIMESTONE FOSSILS

OF IRELAND.

DUBLIN:
PRINTED AT THE UNIVERSITY PRESS,
BY Mom Gill.
1844.

MCZ LIBRARY
HARVARD UNIVERSITY
CAMBRIDGE. MA USA

NO LCi.

Tur descriptions contained in the following Synopsis have been prepared under my direction by

Mr. Frederick M‘Coy, F.G.S., Dublin.
In addition to the Fossils previously known, the Synopsis contains upwards of four hundred

and fifty new species, which have been named and described by Mr. M‘Coy, the whole of
which are contained in my Cabinet, and have been collected by myself and friends from the

Carboniferous Limestone System of Ireland.

RICHARD GRIFFITH.

Firzwitiiam-Piace, DuBLin,
August 28th, 1844.

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ADVERTISEMENT.

In drawing up the following characters of those Fossils of the Irish Carboniferous Series which
I have myself seen, I have endeavoured to express, first, all those characters which seemed
permanent, or of specific value, in each species; second, the principal varieties to which they
are liable; and finally, to point out, when necessary, the distinctions between the nearly allied
species. The Genera have been placed in accordance with their affinities, commencing with
the most highly organized; the Species have been arranged in alphabetical order under each
generic head, to facilitate reference.

I have not noticed either the geological or geographical localities of the species, as from
having examined and named the Collections made by Mr. Griffith, from nearly every carbonife-
rous district in Ireland, the lists are so extensive that it has been thought better to keep them
distinct.

The Collections of Fishes and Plants, although large and interesting, have not, as yet, been
sufficiently examined for publication.

With regard to the drawings, I have spared no pains to make them as accurate as possible;
a large number are entirely from my own pencil, and the others have been most carefully cor-
rected, both as to outline, measurements, and effect, by my own hand.

Since the following Synopsis was sent to Press, and a large portion of it printed off, I
received Koninck’s “ Descriptions des Animaux Fossiles,” &c., Parts I to XII. and although
from the relative positions of the carboniferous deposits of Ireland and Belgium, an almost
perfect similarity might be expected in their organic remains, yet of the large number of new
fossils here put forward, the following only seem identical with M. de Koninck’s species:—
The Nautilus hexagonus, De Kon., is the Nautilus (Discites) planotergatus of this work,
but as there is already a Nautilus hexagonus in the middle Oolite, the name I have proposed
may perhaps be adopted. One of the varieties of the Solarium fallax, De Kon., is my Pla-
tyschisma zonites ; as there are, however, two distinct forms confounded by that author, my

specific name may, perhaps, be retained for this species, and thus the term fallax be limited
b

vi ADVERTISEMENT.

to the second shell figured by Koninck; the fossil seems to me congeneric with those ecarinate
Pleurotomarie, for which I have proposed the name Platyschisma ; its affinity to Solarium is
certainly more remote. Pleurotomaria Hainesii of this work should be changed to Pleuroto-
maria naticoides, De Kon., the species being identical. And finally, the Producta tortilis of
this Synopsis is figured by Koninck as the Productus undatus, Defrance.

In drawing attention to those corrections which have arisen from the almost simultaneous
discovery by M. de Koninck and myself, of a few species, I must express a hope, that I have
not similarly erred with regard to any other authors, either by overlooking or misunderstanding
their descriptions; no one, at least, can be more anxious to avoid such errors, or to correct
them, when in my power.

FREDERICK M‘COY.

Actinoceras
Actinoconchus
Actinocrinus .
Acroculia .
Adelocrinus
Amphidesma .
Amplexus .
Anatina
Anomia

Arca

Astacus
Astarte
Astrea .
Astreopora
Athyris
Atocrinus .
Atrypa .
Aulopora .
Avicula
Axinus .
Bairdia
Bellerophon .
Berenicea .
Brachythyris .
Byssoarea .
Calceola
Calymene .
Campyloceras
Cardiomorpha
Cardium
Caunopora
Ceriopora .
Clymenia .
Conularia .
Corbis .
Crania .
Crenella
Cucullea .
Cyathocrinus .
Cycloceras

TABLE

OF THE GENERA.

ee ee
PAGE.

11 | Cypricardia
149 Cyprina
181 Cyrtia .

44 | Cyrtoceras
174 | Cythere

53 Daphnia

185 Dentalium

51 | Dictuophyllia.
86 | Dirinus

71 Discites

159 | Dithyrocaris .
55 Dolabra

187 | Donax .

191 Echinocrinus .
146 Edmondia .
183 Elenchus .
150 Entomoconchus .
190 | Euomphalus .
82 | Euphemus

63 Favosites .
164 Fenestella .

23 Fissurella .
195 Flustra
144 Fusella.

"7 Gilbertsoerinus .
: 105 Glauconome .
159 Goniatites .

9 Gorgonia .
56 Hemitrypa
56 Ichthyorachis.
193 Inoceramus
194. Jania
17 Kellia .

216 Lacuna

53 Lanistes

105 | Leptagonia
73 Leptena

72 | Leptodomus .
178 Lima

10 | Lingula

Vill

Lithodendron
Lithodomus
Lithostrotion
Littorina .
Loxoceras
Loxonema
Lucina
Lutraria .
Macrocheilus
Mactra
Malleus
Manon
Meleagrina .
Millepora
Modiola .
Monotis
Murchisonia
Mytilus
Naticopsis
Nautilus
Nucula
Orbicula
Orbiculites .
Orthis
Orthoceras .
Palechinus .
Pandora .
Patella
Pecten ..
Pentremites
Phillipsia

Phillipsocrinus .
Phragmoceras .

Pinna .
Platycrinus .
Platyschisma

Pleurodictyum .
Pleurorynchus .
Pleurotomaria .

Polypora
Posidonia

TABLE OF THE GENERA.

PAGE.
. 188
a (6)
. 188

32

Poterioceras
Poteriocrinus
Producta
Psammobia .
Pterinea .
Pteronites
Ptylopora
Pullastra
Retepora .
Reticularia .
Rhodocrinus
Sabella
Sanguinolites
Sedgwickia .
Seminula
Serpula .
Serpulites
Siphonaria .
Siphonophyllia
Solenopsis
Spirifera .
Spiroglyphus
Spirorbis .
Stromatopora
Syringopora
Temnocheilus
Teredo
Toxocrinus .
Tragos
Trigonoceras
Trochella
Turbinolia .
Turbinolopsis .
Turbo
Turritella
Umbrella.
Ungulina
Venerupis
Venus .
Verticillopora .
Vincularia

MOLLUSCA.

Tue Mollusca, or as anatomists more correctly call them, the Heterogangliata, include all the shell-fish, toeether
with several naked groups of little interest to the geologist. The principal divisions of the class are, Ist. The
Cephalopoda, which are the most highly organized, active, and rapacious of the entire group, having a distinct
head, furnished with powerful horny mandibles, large, perfectly-formed eyes, a rudimentary skull and brain,
powerful fins for swimming, and several other peculiarities of structure only found in the Vertebrata, to which
they lead by means of the Fishes; the sexes are distinct. 2nd. The Gasteropoda, including all the spiral
univalve shells, together with some naked groups, but all characterized by having the foot expanded into
a dise for walking ; they have also a head, and two eyes, and usually two or four tentacula; sexes distinct.
3rd. The Dithyra, or bivalves; those are much less highly organized than either the Cephalopoda, or Gastero-
poda, having no head, tentacula, or eyes, and scarcely any powers of locomotion, having no fins for swimming,
or disc-like foot for walking; many of the genera are permanently attached to foreign bodies, either by a
byssus, or by the substance of the shell; they are all females. 4th. Brachiopoda, or arm-footed bivalves, of
which we shall speak more when we come to them. There are, also, the Pteropoda and T'unicata.

oe

CEPHALOPODA.

The Cephalopoda possess the power of swimming in greater perfection than any other Molluscous animals,
and are purely carnivorous in their habits ; they are provided with large arms or feet, which surround the head,
and with which they can walk, seize their prey, and swim. There are several distinct groups. Ist. We have
the Dibranchiata (fig. 1) or naked cuttle fishes, with two gills and three hearts ; they possess Fig. 1.
the power of grasping, in a very remarkable degree, most of the species having two long =~

fleshy arms, furnished with numerous suckers for the purpose ; they are most highly or-
ganized, and approach nearest to the Vertebrata in size, structure, appearance, and habits ; ce
they can swim with tolerable velocity by means of fleshy fins, are very rapacious, and
have the senses of hearing, seeing, and smelling, in higher perfection than any others of
the class ; besides the cranial cartilage, or skull, they have a large dorsal internal support,
which though really analogous to the internal shell of a Limax, and having no organic
connexion with the soft parts of the animal, still forcibly reminds the observer of the dorsal ;,|
spine of the skeleton of the Vertebrata, to which, in their organs of nutrition, prehension, i
respiration, circulation, and the brain and nervous system, and organs of sense, they ap- S
proach more nearly than any other of the molluscous group. 2nd. We have the Sipho-
nifera, or Tetrabranchiata, including all the polythalamous shells which have their chambers connected by a
siphuncle. Those appear to have been of the highest importance in the earlier periods of the earth’s history, the
immense multitudes of Ammonites, Baculites, Scaphites, Hamites, Orbulites, and Nautili, which crowd the

B

6 SYNOPSIS OF THE CHARACTERS OF THE

strata from the chalk to the lias inclusive, and the Goniatites, and gigantic Orthoceratites of the older rocks,
seeming to have been among the chief carnivorous animals of those periods. They have all nearly disappeared
from our seas, Nautilus and Spirula alone remaining to show us the nature of the animals which inhabited the
many chambered shells familiar to the geologist. The Siphonifera are in their internal anatomy most nearly
allied to the Gasteropoda ; they differ remarkably from the Dibranchiata in having four gills, and only one
heart, and most particularly in wanting the internal dorsal lamina, and being covered by an external polythala-
mous shell, the chambers of which are connected by asiphuncle differing in structure according to the family.
The subdivisions of this tribe are so numerous, and would lead us so far away from our subject, that it is better
not to notice them.

Famiry ORTHOCERATID 2.
Genus ORTHOCERAS.

Gen. Ch.—Shell gradually tapering ; smooth; siphuncle central.

There appear to be several subgeneric types even of the genus as here restricted, the first of those is
Orthoceras proper (fig. 2), in which the form is straight conic, the section is circular or nearly so, the si-
phuncle central or nearly so, and the septa simple and placed at right angles to the long axis of the shell.
The econd is Lozoceras*, M‘Coy (fig. 3), in which the section is oval, the septa waved and placed ob-
liquely with respect to the axis of the shell, and the siphuncle is excentric. The third is Trigonoceras’,
Moy (fig. 4), in which the section is heart-shaped, the shell curved, with a concave back bounded on either
side by a distinct ridge or keel, surface smooth, and the siphuncle central. The fourth is Campyloceras®,
M‘Coy (fig. 5), in which the section is circular, the septa simple, and the surface smooth, but the shell
is curved and the siphuncle dorsal. Fifth, Cycloceras', M‘Coy (fig. 6), or those conical species marked with
prominent concentric rings, and having the surface frequently sculptured with transverse scaly lamine, and
often decussated; siphuncle dorsal.

Fig. 2.

Fig. 4. Fig. 5.

This family also contains the genera Poterioceras*, M‘Coy (fig. 7), or the short fusiform orthoceratites, with
contracted mouths, and Actinoceras, Stokes : the latter a doubtful genus.

ORTHOCERAS ATTENUATUM. Flem. (Not of Sow.)
Orthocera attenuata. Fem. An. Phil.

Sp. Ch.—Slender, subcylindrical, very gradually tapering ; septa distant; surface very finely striated
transversely.

This species is allied to the O. Steinhaueri, but is smaller and more slender, and the transverse strize
very much finer; it is seldom more than the eighth of an inch in diameter. This is a more slender shell than
the O. elongato-cinctum of Captain Portlock’s Geological Report, which it otherwise very much resembles.

a = ~

Aogos, oblique, and xepes, a horn. > Tpeic, three; yavic, an angle; and xspz, a horn.
“ Keyervdos, incurved, and xsges, a horn. 4 KyzAcs, a ring, and nEgds.
© Tlozygsov, a vase, and xegas.

CARBONIFEROUS FOSSILS OF IRELAND. 7

ORTHOCERAS crINcTuM. Sow. (not of Phil.)
Orthoceras cinctum: Sov. Min. Con.

Sp. Ch.—Shell very gradually tapering, section circular ; siphuncle central ; septa simple, distant ; surface
with fine, close, sharp, transverse striz.
A few cylindrical fragments of this species have occurred.

ORTHOCERAS CYLINDRACEUM. lem. (Not of Sow.)
Orthocera eylindracea. em. An. Phil.

Sp. Ch.—Very gradually tapering, septa slightly waved, numerous; one and a-half lines apart; siphuncle
very small, central.

This species is not nearly so cylindrical as some others, a specimen four inches in length, tapering about
four lines. The O. inequiseptum (Phil.) is very closely allied to this species, but has the septa closer together.
The O. cylindraceum of Sowerby is quite distinct, and should have the specific name changed.

ORTHOCERAS FILIFERUM. Phil.
Orthoceras filiferum. Phil. Geol. York.

Ch. Sp—Very gradually tapering ; siphuncle central; septa simple; surface with simple transverse striz
or ridges.

The specimens I have referred to this species have the annular ridges larger and more obtuse than in the
O. cinctum.

ORTHOCERAS MuCRONATUM. M‘Coy. (PI. I fig. 1.)

Sp. Ch.—Shell rapidly tapering, smooth; tip mucronate; section oval; siphuncle slightly excentric.

This very curious Orthoceras reminds us by its form of the Belemnites mucronatus of the chalk. The
mucronate tip is a character I have not observed in any other Orthoceras*. Tapers more rapidly than O. ovale.
Length of specimen two inches; breadth at base six lines, tapers three lines.

ORTHOCERAS OVALE. Phil.
Orthoceras ovale. Phil. Geol. York.

Sp. Ch.—Shell very gradually tapering; section broad oval, septa simple; siphuncle nearly central.
This abundant species tapers very slowly ; a specimen three inches long and nine lines in diameter at the
base, diminishes three lines ; the septa are one and a half lines apart; surface smooth.

ORTHOCERAS PYRAMIDALE. Flem.
Orthocera pyramidalis. em. An. Phil.

Sp. Ch.—Shell rapidly tapering ; septa slightly waved, distant ; siphuncle small, central.
This species tapers rather rapidly, a specimen, four and a half inches long, measuring an inch in diameter

* Captain Portlock has figured some mucronate species since the above was written, See Geol. Report, &c.

8 SYNOPSIS OF THE CHARACTERS OF THE

at the larger end, and only four lines at the smaller; the septa are about two lines distant from each other,
rather more at the large end, and about half a line less at the small end.

ORTHOCERAS STEINHAUERI. Sow.
Orthocera Steinhaueri. .Sow. Min. Con.—Orthoceras Steinhaueri. Phil. Geol. York.

Sp. Ch.—Shell very gradually tapering ; section circular ; septa about one and a half lines distant ; very
convex, simple ; siphon lateral ; surface strongly striated transversely.

This species is principally distinguished by the distance and great convexity of its septa. Usually about
quarter of an inch in diameter ; tapers one lne in an inch.

ORTHOCERAS STRIATUM. Sow.
Orthocera striata. Sow. Min. Con.

The O. striatum described by Sowerby, in the Mineral Conchology from the Cork limestone, is stated
to be striated longitudinally. Professor Fleming, in copying Mr. Sowerby’s characters into his work on British
Animals, alters it to transverse striz, specimens agreeing with this latter description are common in the Cork
limestone, and I at first thought, with Professor Fleming, that they might be the true O. striatum. Mr.
Sowerby, however, mentions, in the Sil. System, that the O. striatum differs from the O. filosum (which has
sharp, longitudinal ridges), in the fineness of its striz. I have, however, seen no specimen corresponding with
the original description im this particular, nor does Mr. Sowerby’s figure afford any information.

ORTHOCERAS suULCATULUM. M‘Coy. (PI. L fig. 4.)

Sp. Ch._—Gradually tapering, conic ; section slightly elliptical ; septa one-fifth the diameter, distant from
each other ; surface with coarse, waving, unequal transverse striz.

This species closely resembles Professor Phillips’ figure of the O. cinetum, Sow., but differs from his
description in the coarseness of the transverse sulci (which also distinguishes the surface from O. subflexuosum,
Mist.) From Sowerby’s original figure and description of his O. cinctum it differs entirely, that species being
nearly cylindrical, and with very fine, direct, transverse strie, while the present shell has very coarse, waving,
unequal ridges, and tapers more rapidly in form ; specimens of the true O. cinctum, with those characters, are
not uncommon ; the present species is very rare. A specimen, two inches long, and one inch six lines in dia-
meter at the base ; tapers five lines.

Orruoceras (Loxocrras) Breynu. Mart. sp.
Orthoceratites Breynii. Mart. Pet. Derb.—Orthocera Breynii. Sow. Min. Con.

Sp. Ch.—Shell tapering ; section elliptical; siphuncle in one focus, at the raised edge of the septa;
septa very oblique, numerous ; very slightly concave.

This species has the septa remarkably oblique, and what is very unusual, they are nearly flat ; a specimen
two inches and eight lines long, and one inch three lines at base, tapers four lines; the septa are from one and
a halfto two:lines apart.

Otnoceras (Loxoceras) pistans. M‘Coy. (Pl. IV. fig. 1.)

Sp. Ch.—Tapering five lines in two inches; section elliptical ; septa concave, one-half their lesser dia-
meter distant from each other, oblique in the direction of the shorter diameter of the shell, with a broad, shal-
low wave in the side ; siphuncle nearly central.

CARBONIFEROUS FOSSILS OF IRELAND. 9

This species differs from the O. laterale, Phil. O. imbricatum, Wal. and O. undulatum, Sow., in its
very distant chambers, and from the last species by its nearly central siphuncle ; it also tapers more rapidly
than any of those species. Length of specimen, imperfect at both ends, two inches, three lines, long diameter
at base, one inch one line, short diameter nine lines.

OrtHoceras (Loxoceras) rncomitatum. M‘Coy. (PI. I. fig. 6).

Sp. Ch.—Conical, very rapidly tapering towards the apex; section broad oval; septa slightly oblique,
without wave, or with a very slight one, slightly convex, varying from a fifth to a sixth of their longest diame-
ter in distance from each other; siphuncle slightly excentric.

In the great approximation of the septa, this species resembles the O. imbricatum, Wahl., but differs in its
short, conical form towards the apex, and the septa wanting the strong lateral wave of that species ; it is perhaps
most nearly allied to the O. cylindraceum, Flem., but differs in its proportion, section, and siphuncle. One
specimen of the last, chamber ten lines long, and seven lines in diameter at the base, tapers two lines ; a spe-
cimen, near the apex one inch two lines long, and five lines in diameter at the base, tapered four lines ; the
septa vary from one-half, to one and a half lines apart. Very common in the black slate of Cove of Cork,
but has not occurred elsewhere, and it is unaccompanied by any other fossil.

OrTHOCERAS (LOXOCERAS) LATERALE. Phil. sp.

Orthocera undulatum. Sow. Min. Con.—Orthoceras undulatum and Orthoceras laterale. Phil. Geol. York.—Orthoceras
laterale. Phil. Pal. Foss. Orthoceras subimbricatum. Portk. Geol. Rep.
Sp. Ch.—Shell tapering, thin, smooth; septa numerous, oblique, their edges rising with a wave on each
side; about one and a half lines distant from each other; siphuncle excentric; section oval.
This species is very remarkable for the two lobes in the edge of the septa; a specimen two inches long
and one inch in diameter at the base, tapers four lines.

ORTHOCERAS (TRIGONOCERAS) PARADOXICUM. Sow. SP.
Orthocera paradoxica. Sow. Min. Con.
Sp. Ch.—Shell rapidly tapering, abruptly curved towards the apex; back flat, bounded by two prominent
rounded keels ; front angular, rounded; sides convex in the middle, equal in width to the back ; surface smooth ;
siphuncle nearly central.

The only perfect specimen I have seen, of this curious shell, is in the Collection of the Rev. Dr. Sirr,
from the lower limestone of Kildare.

ORTHOCERAS (CAMPYLOCERAS) ARCUATUM. Phil. sp.

Orthoceras arcuatum. Phil. Geol. York.

Sp. Ch.—Obliquely conical, short, very rapidly enlarging, arched towards the apex; septa very nume-
rous; siphuncle dorsal.

This is the shortest species of the genus with which I am acquainted, and is easily distinguished by its
curved form and smooth surface.

ORTHOCERAS (CAMPYLOCERAS) uNGUIS. Phil. sP.
Orthoceras unguis. Phil. Geol. York.
Sp. Ch.—Elongate, tapering, smooth, curved towards the apex; septa simple, approximate, from one and
a halfto two lines apart; siphuncle nearly dorsal.

This species is larger, and tapers much more gradually than the O. arcuatum, to which it is otherwise
similar.

Cc

10 SYNOPSIS OF THE CHARACTERS OF THE

CYCLOCERAS ANNULARE. Fem. sp.
Orthocera annularis. //em. An. Phil.
Sp. Ch.—Cylindrical, girt with numerous, distant, even transverse rings or ridges, surface smooth.
This beautiful little species is usually found in fragments about an inch in length, and quarter of an inch
in diameter; there are usually about two chambers between two of the external rings.

CycLoceras L&vicATuM. M'‘Coy. (PI. I. fig. 3).

Sp. Ch.—Very gradually tapering, regularly girt with equal rounded rings very slightly oblique, rather
more than their own thickness apart, surface smooth.

This species belongs to the very interesting but difficult division of the Orthoceratites, to which, from the
prominent ring-like elevations on the surface, I have given the name of Cyeloceras; the present species is closely
allied to the O. Ibex (of Sow. not of Phil.), and to the O. annulatus of Heisinger (not of the Min. Conch.) It
is most likely to be confounded with the O. lineolatum, Phil. (O. annulatum of the Geol. York) from which
it is distinguished by its perfectly smooth surface. A specimen one inch three lines in length, and nine lines in

diameter, does not taper more than half a line.

CYCLOCERAS LINEOLATUM. Phil. sp.
Orthoceras lineolatum.—P/zl. Pal. Fos.—Orthoceras annulatum.—P2il. Geol. York. (Not of the Min. Con.)

Sp. Ch.—Very gradually tapering ; surface with numerous rounded oblique rings, the intervening spaces
with fine, obtuse, slightly waving transverse striz.
I have only seen one flattened fragment of this rare species.

Poterroceras. MM‘ Coy.

Gen. Ch.—Shell fusiforme, short; mouth contracted ; siphuncle dilated between the chambers, excentric.

Distinguished from the true Orthoceratites by its short, fusiform contour, and contracted mouth.

Mr. Sowerby proposed the name Gomphoceras for a fusiform species of the Silurian rocks, but that is a
well known genus of Insects.

POTERIOCERAS FUSIFORME. Sow. sp.

Orthocera fusiformis. Sow. Min. Con. Orthoceras fusiforme. Phil. Geol. York.

Sp. Ch.—Elongate, fusiform ; length three times the width; siphuncle excentric towards the dorsal side.

This elegant species is distinguished from all others of the genus by its more elongate form, a specimen
six inches long only measuring one inch seven lines in the widest part. In the same specimen the mouth only
measured nine lines in diameter, the smaller end was six lines in diameter.

PoTERIOCERAS VENTRICOSUM. M‘Coy. (PI. I. fig. 2).

Sp. Ch.—Fusiform, width nearly half the length.

This fine species is one of the largest of the fusiform group of Orthoceratites, to which I have given the ge-
neric name of Poterioceras. It most nearly resembles the common P. fusiforme, but is easily distinguished by its
great proportional width; the section is a very broad oval, siphuncle large, inflated, and slightly excentric.
Length of chambered portion figured three and a half inches, diameter of last chamber four and a half inches,
diameter of thirteenth chamber from the last one inch four lines, septa three lines apart.

CARBONIFEROUS FOSSILS OF IRELAND. 1]

Acrinoceras. Stokes.

Gen. Ch.—Siphuncele containing an internal tube connected with the walls of the siphuncle by radiating
lamellee.

ACTINOCERAS GIGANTEUM. Sow. SP.

Orthocera gigantea.— Sow. Min. Con.—Actinoceras Simmsii.—Stokes, Geol. Trans.

Sp. Ch.—Elongate conic, smooth, or faintly striated across; siphuncle excentric, moniliform, internally
compound as in Ormoceras, radii about four (?), septa numerous, concave, composed of several thick lamelle.

I have ascertained that this fossil has precisely the same structure of siphuncle, both in external form and
internal complexity, as we see in the Ormoceras Bayfieldii: in fact, from the sections I have made, I do not
find a single character to distinguish the genera Actinoceras and Ormoceras from each other. The Orthoceras
giganteum of Sowerby presents all the characters, both of size and external and internal conformation, of the
Actinoceras Simmsii of Stokes. I have, therefore, restored the old specific name, but retained Mr. Stokes’
generic name. Common in the red limestone of Castle Espie Comber, where it sometimes attains a length of
four feet, imperfect at each end. Sowerby, in the Min. Con., when describing the O. giganteum, notices its oc-
currence in this locality.

ACTINOCERAS PYRAMIDATUM. M‘Coy. (PI. I. fig. 5).

. Ch.—Rapidly tapermg; siphuncle moniliform, contracted between the septa, longitudinally wrin-
kled, are tube small, radiating lamelle, three or four; septa double, having a considerable space between
the layers on one side.

This species is easily distinguished from the A. giganteuwm (Simmsii of Stokes) by the rapidity with
which it tapers and the simplicity of the siphuncle.

Cyrtoceras. Gold.

Gen. Ch.—Involute, slightly depressed ; whorls disjoined; septa simple, siphuncle dorsal.

CyrTOCERAS TUBERCULATUM. M‘Coy. (PI. IV. fig. 2).

Sp. Ch.—Elongate, tapering, slightly curved ; section very broad, oval ; surface with about twenty-six
narrow, equal, longitudinal ridges, strongly and regularly tuberculated; intervening spaees rather broader than
the ridges, shall, concave, smooth.

In proportions, curvature, and number of ridges, this closely resembles the O. Gesneri, Mart., but differs in
the tuberculation of the ridges. The smooth intervening spaces, and nodular (not scale-lke) tuberculation of the
ridges, separates it from the C. quindecimale and C. obliquatum ; the form of the latter is also perfectly distinct.
A specimen, imperfect at both ends, one inch and seven lines in length, and eight lines in width at the base,

tapers to five lines.
Puracmoceras. Brod.
Gen. Ch.—Involute compressed, conical; septa simple, crossed by the lines of growth; siphuncle usually
ventral; mouth contracted, outer extremity produced.
PHRAGMOCERAS FLEXISTRIA. (PI. I. fig. 7). M‘Coy.

Sp. Ch.—Discoid, compressed, involute, surface marked with numerous coarse, waving, longitudinal striz,
crossed by fine sigmoidal wrinkles of growth.

12 SYNOPSIS OF THE CHARACTERS OF THE

If this be a species of Phragmoceras, it must have been nearly as involute as P. nautilium; on the other
hand, in the absence of chambers, the portion preserved bears some resemblance to certain of the silurian
Euomphali, as E. lineatus, but from all those it is distinguished by the small size of the inner or ventral curve,
and in either case the species is easily known by its close, flexuous, thread-like strie.

Famity NAUTILIDZ.

Ist. The genus Nautilus may be viewed as the type of the whole ; the species it contains are large, simply
formed shells, having a very wide geological range; they are involute, the last chamber usually enveloping
all the rest, and being large enough to contain the animal ; the septa are simple, or entire at their edges, and
concave outwardly ; the siphuncle is discontinuous, and usually central. I have separated two groups, T'emno-
cheilus and Discites, the characters of which will be given under those heads. 2nd. Seems to be the genus
Goniatites, De Haan, which has the edges of the septa bent angularly, so as to assume a complexity little short
of what we see in the true Ammonites. 3rd. Bellerophon, although strongly allied to Argonauta, may, per-
haps, be left in this family for the present, on account of the greater thickness of the shell, and its larger and
more perfectly formed spire. The genus Phragmoceras of Brodrip, appears to belong to the present family,
rather than to the Orthoceratide, to which, however, it obviously approaches ; the compressed, curved form
of these shells is very different from that of Orthoceras, but approaches closely to what might be considered
as a partially unrolled Nautilus, from which it differs in no very important point of structure; some of the spe-
cies are almost perfectly volute, as the P. nautilium.

GonraTiTEs. De Haan.

Gen. Ch.—Shell discoid, involute; edges of the septa bent into distinct angles ; siphuncle dorsal.

This remarkable genus appears to be characteristic of the carboniferous series (including the carb. slate
or upper Devonian). It is found in every marine member of this group, andin some of them it is the most abun-
dant fossil, while neither above nor below do we find any shells possessing the peculiar structure of the genus.

GontraTites Brown. M/' Coy. (PL IV. fig. 17).

Sp. Ch.—Discoid, subglobose, sides flattened; umbilicus large, acute-edged, exceeding one-third the
diameter of the shell; surface smooth; septa, dorsal lobe small, bifid; dorsal sinus acute ; first lateral lobe slightly
exceeding the dorsal in length, very wide, rounded; lateral smus twice as long as the dorsal, acute, lmguiform ;
second lateral lobe very wide, obtusely rounded.

From the G. striatus, Sow., which the species most resembles, it is distinguished internally by its much
shorter and wider first lateral lobe; the same character distinguishes it from the G. sphericus, Sow., and from
both it is distinguished externally by its smooth surface, and from all the species of the same form, by the large
size of the umbilicus. Diameter two inches two lines, thickness one inch one line.

GONIATITES CRENISTRIA. Phil.
Goniatites crenistria.— Phil. Geol. York.

Sp. Ch.—Spheroidal, umbilicus very small ; surface with delicate, slightly waving, transverse striz, which
are crenulated by very fine spiral lines.

This beautiful shell is completely reticulated by the crossing of the most delicate spiral and transverse
striz ; it varies considerably in shape, being sometimes almost spherical, and at other times compressed; the
markings of the surface will, however, at all times distinguish it; the septa are exactly similar to those of the
G. striatus ; diameter one and a half inches, thickness ten lines.

CARBONIFEROUS FOSSILS OF IRELAND. 13

GonratTiTEs Discus. M'Coy. (Pl. II. fig. 6).

Sp. Ch.—Discoid, compressed, smooth ; sides flattened, back rounded ; volutions six ; entirely exposed ;
septa, dorsal sinus single, acute; dorsal lobe short, rounded; first lateral sinus bifid ; first lateral lobe twice as
long as the dorsal lobe, rounded, sides parallel ; second lateral sinus narrow, pointed, mucronate, equal in
length to first lateral smus ; second lateral lobe short, rounded ; marginal sinus very short, acute.

This Goniatite belongs to the remarkable little group including the G. Henslowi, G.cyclolobus, G. mixo-
lobus, &c. and which, from the peculiarities both of septa, and external form, might make a very natural genus.
Diameter one inch seven lines; length of mouth five lines; width four lines.

GONIATITES EXCAVATUS. Phil.
Goniatites excavatus. Phil. Geol. York, and Pal. Fos.

Sp. Ch.—Discoid, depressed ; back rounded ; umbilicus large, margin acute ; surface with fine, branching,
curved, transverse stria ; septa, dorsal lobe short, bifid; first lateral sinus acute, angular ; first lateral lobe
very large, obtusely rounded ; inner margins parallel ; lateral sinus acute.

This species is lable to be confounded with the G. reticulatus, but is distinct both by its septa (having the
lateral sinus angular, pointed, instead of being wide and obtuse, or with a small mucronate point, as in that spe-
cies) and in wanting the spiral striation: the form too is not so depressed, and the back is more rounded than
in that shell.

GonratiTes FAscicutatus. M‘Coy. (PI. II fig. 8).

Sp. Ch.—Discoid ; umbilicus very large ; inner whorls partly exposed ; back very convex, broad, crossed
by numerous unequal bundles of fine transverse ridges, having a deep retral wave on the back ; the bundles of
transverse ridges about their own diameter apart, the intervening spaces being concave and smooth.

This beautifully marked species is distinguished from the G. Listeri, to which it is nearly allied, by the
transverse ribs, instead of being simply rounded, as in that species, being formed each of a bundle of thin, un-
equal ridges ; the umbilicus is also smaller, and with a rounded edge ; the margin is plicated by the passage
over it of the ridges ; this part bears large tubercles in the G. Listeri, which is a much more common species.
Diameter one inch six lines, thickness of last whorl eleven lines.

GontatTitEs Gissont. Phil.
Goniatites Gibsoni. Phil. Geol. York.

Sp. Ch.—Discoid, whorls, five or six, one-third exposed; back rounded; mouth broad, oval, a little wider
than long; whorls crossed by sharp, forked ribs, most prominent at the edge of the umbilicus.

T am not acquainted with the septa of this remarkable little shell, which'in general form, and in the mark-
ing of its surface, more closely resembles an Ammonite than the present genus. There are about five or six turns
in the spire; the volutions are convex ; the back broad and rounded ; the radiating ribs rise boldly from the
edge ofthe umbilicus, and, bending slightly forward, branch about the middle of the side into two smaller ones,
which pass over the back ; the surface between the ribs is perfectly smooth. Diameter four lies, thickness

one line.
GONIATITES INTERCOSTALIS. Phil.
Goniatites intercostalis. Phil. Geol. York.
Sp. Ch.—Discoid depressed ; whorls two-thirds exposed ; back broad, obtusely angular in the middle ;

sides with radiating ribs, which form distinct tubercles at the dorsal angle; between these there are coarse
spiral striz.

D

14 SYNOPSIS OF THE CHARACTERS OF THE

I have not as yet seen the septa of this very rare shell; the back is broad, bounded by an obtuse
angle, from whence the sides are concave, exposing rather more than one half of each whorl; the whorls are
about four in number, spirally striated, with rather distant, strong, radiating ribs, forming tubercles when they
reach the ridge which bounds the back, where they cease. Diameter one inch, thickness seven lines.

GoNIATITEs LATUS. M‘Coy. (Pl. II fig. 7).

Sp. Ch.—Globose, back very broad, rounded ; mouth transversely elliptical, twice and half as wide as
long ; umbilicus rounded, angular, very deep, exposing the edges of the preceding whorls; surface smooth,
with a few distant, bent constrictions ; septa, dorsal lobe simple, twice as long as wide, rounded ; dorsal sinus
very wide, rounded ; lateral lobe half the length of the dorsal, width equal to the length, acute ; lateral sinus
wide, shallow ; surface smooth.

This is one of the very few Goniatites of the mountain limestone, in which the dorsal lobe is simple, as
in those of the inferior rocks, it resembles the G. Newggerathii, but is much more globose, and has fewer
whorls. Diameter one inch three lines, width of mouth ten lines, length of mouth four lines.

GONIATITES ListTERI. Mart. sp.

Ammonites Listeri. Mart. Pet. Derb—Ammonites Listeri. Sow. Min. Con.—Goniatites Listeri. Phil. Geol. York.

Sp. Ch.—Spheroidal depressed ; mouth twice as wide as long ; umbilicus very deep, conical, exposing
the angle of the internal whorls ; edge of the umbilicus tuberculate ; surface with distinct transverse striz, or
ridges, having a shallow, retral wave as they pass over the broad back ; septa, dorsal lobe bifid, dorsal sinus
long, acute; first lateral lobe very large, rounded ; lateral sinus little deeper than the dorsal sinus ; wide,
mucronate, or suddenly pointed.

Tn this species the umbilicus is so large that all the whorls are half exposed, so that the toothed or plaited
edge of the umbilicus can be seen all the way; the back is broad, slightly convex, and transversely striated.
Diameter one and a half inches, thickness one inch.

GONIATITES Micronotus. Phil.

Goniatites micronotus. Pi. Geol. York.

Sp. Ch.—Discoid, depressed, back rounded; umbilicus very small, rounded; surface with delicate, trans-
verse, curved striz; septa, dorsal lobe very small, acute, first lateral lobe very large, rounded at the extremity,
with their imner edges nearly parallel, dorsal and lateral sinus small and rounded.

This obscure species is known from the young of G. obtusus and G. striolatus by the small size
of the umbilicus, the form of the septa distinguishes it from all the allied species. Diameter one inch, thick-
ness six lines.

GONIATITES MUTABILIS. Phil.
Goniatites mutabilis. PA. Geol. York.

Sp. Ch.—Globose, smooth; umbilicus wide, acute-edged; mouth more than twice as wide as long; back
broad, rounded; constrictions direct.

One or two specimens of this simply formed shell have occurred ; the septa have not been seen as yet, nei-
ther have I seen any specimens corresponding to Professor Phillips’s figure of the adult. Diameter four lines,
thickness three lines.

CARBONIFEROUS FOSSILS OF IRELAND. 15

GONIATITES optusus. Phil.
Goniatites obtusus. Pl. Geol. York.

Sp. Ch.—Discoid, gibbous, somewhat compressed, with nearly parallel sides, and broad, obtusely-rounded
back ; umbilicus very small; surface, when well preserved, very finely striated transversely ; striae waved ;
septa, dorsal lobe small, obscurely bifid, dorsal sinus angular, acute ; first lateral lobe three times the length of
the dorsal, oblong, rounded; lateral sinus wide, mucronate.

This species bears some resemblance to the Goniatites striatus and G. crenistria in general appearance,
but is distinguished from the first by its transverse striz, smaller umbilicus, and by its rounded lateral lobes,
and from the latter by the surface not being reticulated ; the back is broad and rounded, but the sides are but
slightly convex; diameter one inch six lines, thickness ten lines.

GONIATITES RETICULATUS. Phil.
Goniatites reticulatus. Phil. Geol. York.

Sp. Ch.—Discoid, depressed, back angulated; umbilicus conical, smooth, with an angular margin; surface
with acute transverse branching, curved striz, crenulated by fine spiral lines ; septa, dorsal lobe short, obscurely
bifid, dorsal sinus small, rounded; first lateral lobe narrow, rounded; lateral sinus large, mucronate.

It sometimes happens that casts only of the smooth conical umbilicus remain, but more frequently it
occurs crushed or flattened, with the surface perfect, shewing distinctly the beautifully curved dichotomous striz,
which, under the lens, are seen to be crossed by delicate spiral stria. The young shells are more globose, and
have a rounded umbilicus. Diameter from one to two inches.

GONIATITES spHzARIcUS. Mart. sp.

Goniatites sphericus. Mart. Pet. Derb.— Ammonites sphericus. Sow. Min. Con.—Goniatites sphaericus. Phil. Geol. York.

Sp. Ch.—Globular, umbilicus small, acute-edged; surface spirally striated; septa, dorsal lobe bifid, dorsal
sinus short, acute, first lateral lobe obtuse, four times the length of the dorsal lobe; second lateral lobe very
obtuse, nearly as long as the first.

This species is almost perfectly spherical in general form; the umbilicus is small, rounded, and with a sharp
edge; when finely preserved the surface is spirally striated, but it is more commonly found without the exter-
nal shell. Diameter one inch ten lines, thickness one inch five lines.

GoNIATITES SPHEROIDALIS. M‘Coy. (PI. IV. fig. 18).

Sp. Ch.—Spheroidal, sides slightly flattened, thickness equal to two-thirds the diameter; umbilicus rathe
large, acute-edged; shell marked with very fine transverse strie, and having faint, internal, sigmoidal ridges;
septa, dorsal lobe bifid; lateral lobe very short, scarcely exceeding the dorsal lobe in length, broad, rounded, with
parallel sides; dorsal smus acute; lateral sinus very large, mucronate.

This species is much thicker, or more nearly spherical, than either the G. crenistria, G. obtusus, or G.
striolatus; from the first and second it differs, besides its thickness, in the greater size of the umbilicus, and
width of the lateral lobes of the septa, and from the latter, by its large size, very long lateral sinus, short lateral
lobe, and spherical form; from the G. sphericus it differs in the short, wide, lateral lobes, longer lateral sinus,
and the absence of spiral stria. Diameter one inch six lines, thickness one inch, diameter of umbilicus six
lines. =

16 SYNOPSIS OF THE CHARACTERS OF THE

GONIATITES SPIRALIS. Phil.

Goniatites spiralis. Pl. Pal. Fos.—Goniatites granosus. Porth. Geol. Rep.

Sp. Ch.—Discoid (compressed?) umbilicus very small, rounded; surface, with numerous close, equal, finely
granulated, spiral striz, the spaces between which are transversely striated.

All the specimens of this shell which I have seen were quite flat from compression, and I am not aware

of the true proportion which the thickness should bear to the diameter, nor have I seen the septa. Diameter

usually about two inches.

GONIATITES STRIATUS. Sow. SP.

Ammonites striatus. Sow. Min. Con,—Goniatites striatus. Phil. Geol. York.

Sp. Ch.—Spheroidal, slightly depressed, finely striated longitudinally ; umbilicus small, rounded, with an
obtuse margin ; septa, dorsal lobe bifid ; dorsal sinus angular, acute ; first lateral lobe angular, acute, rather
more than twice the length of the dorsal lobe ; second lateral lobe blunt, shorter than the first lateral lobe ; late-
ral sinus angular, acute, not longer than the dorsal sinus.

This species is known at once from the G. sphericus, by its more compressed form, and acutely angular
first lateral lobe. Both these species exhibit variable internal ridges on the cast. Diameter two inches, thick-
ness one inch.

GONIATITES STRIOLATUS. Phil.
Goniatites striolatus. Phil. Geol. York.

Sp. Ch.—Subglobose ; sides slightly convex, gently sloping towards the back, which is narrow, rounded ;
umbilicus large, acute-edged ; surface with fine, rather distant, straight, transverse strie ; septa, dorsal lobe
very short, bifid ; dorsal sinuses wide, pointed ; lateral lobes large, obtusely rounded ; lateral sinus moderate,
mucronate.

This pretty species differs from the young of G. obtusus, by having the back narrower, and the sides
sloping towards it, not parallel, its larger umbilicus, and more obtusely rounded first lateral lobe. Diameter
about one inch, thickness five lines.

GONIATITES TRUNCATUS. Phil.
Goniatites truncatus. Phil. Geol. York.

Sp. Ch.—Discoid, compressed ; sides flattened ; back flat, or slightly convex, meeting the sides nearly at
right angles ; umbilicus very small ; surface with very fine transverse strix.

Resembles the G@. obtusus, but easily distinguished by its more compressed form, flatter sides, and flat,
truncate back. Diameter one inch and a half, thickness six lines.

GONIATITES virTIGER. Phil.
Goniatites vittiger. Phil. Geol. York.

Sp. Ch.—Discoid, compressed, smooth; sides convex, concave towards the keel; back with a large,
square keel ; umbilicus wide, shallow, exposing the edges of the whorls ; whorls five or six.
I have not yet seen the septa of this curious shell ; it resembles a Spirorbis when one side only is seen.

CARBONIFEROUS FOSSILS OF IRELAND. 17

CrymentA. Dhinst.
Endosiphonites. Ansted.

Gen. Ch.—Discoid involute; septa with one forward bend on the back; siphuncle ventral.

This genus is very distinct from Goniatites, by its ventral instead of dorsal siphuncle, and the comparative
simplicity of the septa. There is an undetermined species common in the limestone of Cregg Nobber, resem-
bling the C. levigata, but with fewer, and more compressed whorls, and rounded back, without keel.

CLYMENIA PLURISEPTA. Phil.
Clymenia plurisepta. Pil. Pal. Fos.

Sp. Ch.—Discoid (smooth ?) umbilicus large, edge rounded; sides very slightly convex; thickness rapidly
diminishing from the edge of the umbilicus to the back, which is narrow, rounded ; septa about one line apart.
Diameter one inch, thickness half an inch.

CLYMENIA SAGITTALIS. Phil.
Clymenia sagittalis, Phil. Pal. Fos.

This species differs from the last principally in bemg more compressed, and having a much smaller umbi-
licus.

Discites. MM‘ Coy.

Gen. Ch.—Shell discoid, whorls exposed, quadrangular; back flat or concave; septa
concave outwardly, with an acute sinus at each of the latero-dorsal angles, and a deep,
rounded, dorsal sinus on the back, the concavity towards the mouth; siphuncle towards
the dorsal margin.

This genus is distinguished from all others of the family by the quadraneular form of
the whorls, these are all exposed, and are more numerous and more nearly equal in size than
in any of the other genera; the angle formed by the meeting of the flat side with the flat or
concave back, produces a long, acute, lateral sinus in the edge of the septa, reminding us of
Clymenia, the point directed towards the mouth; between these on the back, there is a large
obtuse sinus, the concavity of which is towards the mouth (fig. 8). The siphunele is dorsal,
or nearly so.

Nautiwus (Discires) costettatus. M‘Coy. (PI. II. fig. 4).

Sp. Ch.—Discoid, inner whorls exposed ; volutions very convex; back rounded; umbilical edge steep,
smooth, whorls ornamented with about nineteen narrow, equal, prominent longitudinal ridges, separated by a
space rather greater than twice their own diameter; septa very convex; siphuncle central.

This species is easily distinguished by the width of its volutions, broad, rounded back, and few dis-
tant longitudinal ridges; the number of whorls is about four; the width of the mouth from side to side is rather
greater than the length from before backwards; the volutions are almost wholly exposed in a steep, smooth,
umbilicus, the spaces between the ridges on the surface appear nearly smooth to the naked eye, but under the
lens are seen to be marked with very fine transverse retroflexed striw. Diameter one inch four lines; width of
mouth eight lines, leneth six lines.

Nautiwus (Discrrss) piscors. M‘Coy. (PI. III. fig. 5).

Sp. Ch.—Discoid, compressed, whorls five, entirely exposed, quadrate, back convex, equal in width
to the sides exclusive of the umbilical slope, sides slightly flattened, evenly convex; surface of the young shell

E

18 SYNOPSIS OF THE CHARACTERS OF THE

(and inner whorls of the old) marked with strong longitudinal (spiral) sulci, crossed by very fine striz ; last volu-
tion of adult specimens marked with coarse transverse sigmoidal striz only.

I have named this species from the remarkable difference in striation between the young and old volutions,
which is so great they might be taken for different species; it resembles the N. subsulcatus, Phil., most nearly,
but is distinguished by the character of the striation, and by not having, at any period of growth, either
the two keels on the back, the keel on the sides, or any concavity on those latter, the sides being regularly con-
vex, and the back broader in proportion to the width of the sides. Diameter, three inches one line; length of
mouth, one inch one line; width, eleven lines. It grows much larger.

Nautiuus (Discires) tatiporsatus. M‘Coy. (Pl. IV. fig. 16).

Sp. Ch.—Discoid compressed, smooth ; volutions entirely exposed in a very wide, shallow, undefined um-
bilicus ; whorls cordate, triangular ; sides margined exteriorly by a prominent rim or keel, within which is a
shallow sulcus, from whence into the umbilicus the sides are evenly convex; back very broad, flat, nearly
equalling the side m width.

This species differs, from all of the genus that I know, in the cordate or triangular section of the whorls,
and in the prominent margin to the sides, formed, as it were, by the projection of the flat back. There are very
faint traces of spiral striz on the inner, or young volutions ; septa simple, concave outwardly. Diameter, one
inch seven lines ; length of mouth, six lines ; width of back, five lines.

Navtiwus (Discires) mutans. MM‘Coy. (Pl. Il fig. 7).

Sp. Ch.—Discoid, very much compressed ; whorls five or six, entirely exposed, quadrangular, aperture sa-
gitate; back very concave, less than one-fourth the width of the side, umbilical slope as broad as the back,
steep, concave, with an angular margin; two outer whorls in adult specimens perfectly smooth, inner ones
marked with strong equal spiral sulci.

The change of character of the surface from the inner to the outer whorls is even greater than in the
Nautilus (Discites) discors, M‘Coy, the inner volutions being spirally striated as in that species, but the outer
turns bemg perfectly smooth; it differs from that species, besides the smoothness of the outer whorls, in the
much more compressed form; long, narrow mouth, and the narrow and very concave back; from the N. (Dis-
cites) trochlea, M‘Coy, it differs in the striation of the inner whorls. Diameter four inches four lines ; width of
side, exclusive of marginal slope, one inch two lines; width of back three lines, greatest width of mouth at the
umbilical angles seven lines.

Navtitus (Discires) oxystomus. Phil. sp.
Nautilus oxystomus. Phil. Geol. York.

Sp. Ch.—Discoid, compressed, smooth, back acute ; volutions half exposed ; sides of the inner whorls with
two sharp spiral ridges.

Several fragments of this remarkable species have occurred to me, but none of them shewed more of the
septa than has been already indicated by Professor Phillips; the length of the aperture is equal to half the
diameter of the shell.

Nautitus (Discires) PLANoTERGATUS. ‘M‘Coy. (PI. IL fig. 2).
Sp. Ch.—Discoid, compressed, whorls quadrangular; sides flat, smooth; back flat, smooth, three-fourths the
width of the sides ; inner whorls exposed, about five in number ; septa simple, about half an inch apart.
This fine species often reaches to ten inches in diameter ; it is distinguished from the N. complanatus,

CARBONIFEROUS FOSSILS OF IRELAND. 19

Sow., by its very broad, flat back, and simple septa ; from the N. discus, Sow., by the broad, flat back, and
the greater spaces between the chambers; the N. guadratus, Flem. is distinguished by its striated surface.
Diameter, four inches ; width of last whorl, one and a-half inches ; breadth of back, one inch three lines.

Navtitus (Discires) sussutcatus. Phil. sp.
Nautilus subsuleatus. Phil. Geol. York.—Nautilus subsulcatus. Sow. Geol. Trans.

Sp. Ch.—Whorls about five, entirely exposed ; back narrow, mesial portion concave in the young, flatter
in adult specimens, separated from the lateral portion of the back by a ridge on each side ; lateral portions of the
back flat, oblique, narrower than the mesial portion ; sides divided nearly in the middle by a spiral ridge ; the
outer portion of each side being concave, the inner slightly convex ; surface sigmoidally striated ; siphuncle
dorsal. Diameter three and a half inches, thickness eleven lines.

Nautiwus (Discrres) sutcatus. Sow. sp.
Nautilus sulcatus. Sow. Min. Con.—Nautilus sulcatus. Phil. Geol. York.

Sp. Ch—Whorls oblong ; greatest thickness at the edge of the umbilicus; three keels on each side, exclu-
sive of the raised edge of the umbilicus, or of the latero-dorsal angle, including between them four grooves,
two large next the back, and two small next the umbilicus ; siphuncle nearly dorsal ; surface with sharp, sig-
moidal striz.

The great number ‘of longitudinal grooves which furrow the back and sides of this species, give it a very
strongly marked character; there are five keels on each side, one forming the angle which bounds the back; at
a little distance from this, on the side, there is another larger, the two being separated by a shallow, concave
space ; there is then a concave space exceeding in width the last two keels; from this to the edge of the umbi-
licus there are three small keels separated by two small furrows; the back is concave; the whorls are nearly all
exposed; the surface has fine sigmoidal striz. Diameter one inch seven lines; thickness seven lines; length of
mouth eight lines.

Nautiwvs (Discites) TETRAGONuS. Phil. sp.
Nautilus tetragonus. Phil. Geol. York.

Sp. Ch.—Discoid, compressed ; whorls quadrangular, back flat or slightly concave, with a small longitudi-
nal ridge on each side; umbilicus very large, circular, sides with sharp curved striz, forming thin, prominent
plaits at the edges.

This shell is very local in its distribution; it varies considerably in its character, according to the age and
state of conservation of the specimen. Diameter about one inch.

Navtitus (Discrres) TrocuLea. M‘Coy. (PI. III. fig. 4).

Sp.Ch.—Discoid, compressed, smooth, volutions exposed, sides broad, slightly convex ; back very concave,
narrower than the inner edge of the volution, considerably less than one-half the width of the sides; margin of
the septa very concave outwardly on the sides and back, produced into a very acute angle on the latero-dorsal
ridges.

This species may be distinguished from the N. planotergatus, M‘Coy, by the deep concavity of the back,
which is also much narrower than in that species, the umbilicus is also smaller. The large size of the
umbilicus distinguishes it from the N. planidorsatus, Portk. Thickness of last whorl (breadth of side) two
inches four lines, width of back eleven lines.

20 SYNOPSIS OF THE CHARACTERS OF THE

Tremnocuerwus*. M‘Coy.

Gen. Ch.—Shell discoid, involute, umbilicate ; a deep sinus in the middle of the outer lip; septa simple,
siphuncle central.

This subgenus will comprehend the greater number of the Nawtili of the carboniferous series. From the
true genus Nautilus it is externally distinguished by its discoid, flattened form, and the greater number of its
volutions, all of which are exposed in a wide, conical umbilicus; one of the most important structural differences
is, the deep notch, or sinus, to be found in the outer lip of the present group, from which it derives its name.

NAvTILUS (TEMNOCHEILUS) BIANGULATUS. Sow. SP.
Nautilus biangulatus. Sow. Min. Con.—Nautilus biangulatus. Phil. Geol. York.

Sp. Ch.—Discoid ; volutions half exposed by a large, conical umbilicus, bounded by a raised margin or
keel ; back evenly convex ; septa very convex ; siphuncle central.

This species is remarkable for the sharp, prominent keel which surrounds the umbilicus; between
the prominent angle on each side, the back is slightly convex, but without any other keels or furrows ; this
forms the chief external difference between this species and the JT. cariniferus. The mouth is about twice as
wide as long ; the septa very concave outwardly ; stphuncle central, or nearly so; surface smooth. Diameter
four inches, thickness two and a half inches.

Navtizus (TEMNOCHEILUS) BISTRIALIS. Phil. sp.
Nautilus bistrialis. Phi. Geol. York.
Sp. Ch.—Orbicular, compressed, smooth; back broad, rounded; umbilicus very large, circular, with two
strong spiral grooves within the edge.

This species occurs very rarely, and generally without the external shell; the sculptured edge of the um-
bilicus is a very curious peculiarity.

Nautitus (TEMNOCHEILUS) CARINIFERUS. Sow. sp.
Nautilus cariniferus. Sow. Min. Con.—Nautilus carinatus et cariniferus. Phil. Geol. York.

Sp. Ch.—Discoid, volutions subpentagonal, half exposed by a wide conical umbilicus, which is margined
by an acute keel or ridge, between which and the back there is on each side an obtuse ridge; siphuncle mar-
ginal.

This species differs from the 7’. biangulatus principally in having on each side an obtuse keel on the
back; the space between the obtuse keel and the edge of the umbilicus is concave, while that between the one
keel and the other is convex; the general form is that of the N. biangulatus, which it resembles in many
respects; the two keels on the back are sharp and distinct in the young shells, but become more obtuse as they
advance in age, and in very old specimens they are sometimes quite effaced, and are then scarcely distinguish-
able from the N. biangulatus ; the mouth is twice as wide as long; the siphuncle is nearly dorsal. Diameter
three and a half inches; thickness two inches two lines.

Nautiwus (Trmnocuemus) coronatus. M‘Coy. (Pl. IV. fig. 15).

Sp. Ch.—Discoid, subglobose ; inner whorls half exposed in a large, steep umbilicus, the acute edge of

which is crowned with large, compressed, blunt tubercles; back flattened; surface smooth; septa simple; si-
phuncle nearly central.

* Tizv, seco; and yetAes, labrum.

CARBONIFEROUS FOSSILS OF IRELAND. 21

This beautiful species has the exact form of the N. cariniferus, Sow., or with the back slightly more flat-
tened, but differs from it in the row of close, blunt, compressed tubercles, which ornaments the edge of the
umbilicus on each side. Diameter two inches six lines; length of mouth ten lines; width of mouth two inches.

The specimen figured was kindly lent by Dr. Haines, of Cork.

Nautitus (Temnocaeiwus) costaris. Phil. sp.
Nautilus costalis. Phil. Geol. York.

Sp. Ch.—Spheroidal, depressed; umbilicus small, deep; whorls crossed by sharp, direct, transverse ridges,
and fine striae; a few deep, direct constrictions on the cast.

This species is at once distinguished by the curious transverse plaiting of the whorls; these plaits are
few and obtuse near the umbilicus, but become thinner, sharper, and more numerous as they pass over the
broad, rounded back, between these are finer strie; the sides are gently convex, the back rounded, and the
mouth lunate by the deep insertion of the preceding whorl. Diameter three and a half inches. The N. funa-
tus has thicker and fewer transverse ridges.

Nautitus (TemNocuerus) crenNATusS. M‘Coy. (PI. II. fig. 9).

Sp. Ch.—Discoid ; inner whorls exposed by a large umbilicus ; two strongly toothed, or serrated, keels,
within the umbilicus, and one obtuse keel outside it; sinus in the lip shallow.

I have only seen a fragment of the last chamber of this shell, but its characters are so strongly marked that
I have no hesitation in proposing it as a distinct species ; the two notched or crenated ridges within the umbi-
licus give a very striking appearance to the shell; the back is flattened, with an obscure keel on each side ; the
mouth is hexagonal, and very much depressed, being three times as wide as long. I am not aware how many
whorls there were, but suppose they were fewer than in the N. béangluatus; neither do I know the diameter of
the shell when perfect, but suppose it to be about the size of the N. cariniferus; the fragment figured measures
one and a half inches across the back.

Nautizus (TemNocuErtus) rurcatus. M‘Coy. (Pl. IV. fig. 13).

Sp. Ch.—Discoid, compressed ; sides gently curved; back rather narrow, rounded; umbilicus small,
slightly exposing the whorls ; surface marked with large, strong, rounded ribs, each of which, a short distance
from the umbilicus, regularly branches into two of equal thickness, which, making a rather acute, forward bend,
in passing over the back, unite again on the opposite side, before reaching the umbilicus; intervening spaces
wider than the ribs, concave, smooth.

This species can only be confounded with the N. funatus, compared with which the following differences
are observable: in specimens of the same size, the ridges are nearly three times more numerous, in a given space,
in the N. funatus, than in the present species. In the former, all the ridges are simple, equal, and proceed di-
rectly across the shell; while in the latter each rib branches boldly and regularly into two strong ridges, before
passing over the back; the umbilicus, also, is smaller in the N. furcatus than in the N. funatus, and exposes
less of the whorls. The specimens are generally elliptical. Diameter two inches seven lines; diameter of
last whorl thirteen lines; thickness eleven lines. The specimen figured was obligingly contributed by Dr.

Haines of Cork.

Navtitus (TEeMNocHEILUS) GLopaTus. Sow. sp.
Nautilus globatus. Sow. Min. Con.
Sp. Ch.—Subglobose, discoid; back very broad, slightly flattened; a deep sinus in the edge of the outer
lip; umbilicus moderate, deep, with an angular edge; whorls increasing very rapidly; the last whorl slightly

produced, flattened below.
F

22 SYNOPSIS OF THE CHARACTERS OF THE

This species has but few whorls, the inner ones being partly concealed by those which follow; they in-
crease very rapidly in size, so that in old individuals the spire does not indent the mouth; the back is flattened,
and, in young individuals, the sides are also somewhat flattened; when very young, there are some spiral
grooves on the back, and in that state has perhaps been described as a distinct species; the mouth is very large
and semicircular, with a deep sinus in the outer lip. Professor Phillips’ shell seems distinct.

Navtitus (TEMNOCHEILUS) MULTICARINATUS. Sow. SP.
Nautilus multicarinatus. Sow. Min. Con.
Sp. Ch.—Discoid; inner whorls half exposed in a deep, conical umbilicus; back flattened, with three or
four keels on each side; one keel within the edge of the umbilicus.
This species much resembles the N. cariniferus in form, but it is distinguished by the number of keels
with which it is marked; there are four on each side in young, well-marked individuals, but by age the keels
on the back become more or less effaced; the keel within the umbilicus is more constant than any of the others,

in fact, I do not remember an instance in which it was not present. Diameter four inches, thickness two
inches and a half.

Nautitus (Temnocuettus) prneuis. M‘Coy. (PL IV. fig. 12).

Sp. Ch.—Discoid, smooth; umbilicus rather small, conical, half exposing the inner volutions ; whorls about
four, gradually increasing, ventricose, carinated on the sides; keel vanishing towards the mouth; back broad,
rounded; umbilical slope convex; mouth broad, oval, about one-third wider than long.

This species most nearly resembles the Nautilus (Temnocheilus) cariniferus but differs in having its
volutions less broad and more ventricose, the umbilicus smaller, and its sides convex, and im the much greater
convexity of the back. The deep sinus in the outer lip, found in all the species of Temnocheilus, is visible
in the specimen figured. Diameter two inches one line; length of mouth nine lines; width of mouth one inch
two lines.

The specimen figured is one of several rarities from the cabinet of Mr. Newenham of Cork.

Navtitus (Temnocuerzus) porcatus. M‘Coy. (PI. IIL fig. 6).

Sp. Ch.—Discoid; back very broad, flattened, having a slight mesial suleus, and marked by ten spiral
ridges, the two mesial ones being smallest; umbilicus very large, with an angular edge; one spiral keel similar
to the dorsal ones within the edge of the umbilicus; surface smooth.

This species resembles the N. multicarinatus, Sow., but is distinguished by its smaller size, the greater num-
ber and equality of the spiral ridges, and the mesial hollow.

Navtitus (Temnocuermus) suncrrerus. Phil. sp.
Nautilus sulciferus. Phil. Geol. York.

Sp. Ch.—Globose ; umbilicus large, with a prominent angular margin; back convex, flattened and sulca-
ted in the middle.

Only a very few imperfect specimens have occurred of this species.

Nautitus (TEMNocHEILUS) TUBERCULATUS. Sow. SP.
Nautilus tuberculatus. Sow. Min. Con.—Nautilus tuberculatus. Phil. Geol. York.
I have not seen in any of the Irish rocks, specimens which would exactly agree with the true N. Tuber-
culatus, Sow., which has the general form of the Naztilus (Temnocheilus) coronatus, M‘Coy, but has the

whorls thicker, the umbilical slopes tumid, and the’ tubercles of the edge of the umbilicus fewer, larger,
rounder, and more nodulous than in that species.

CARBONIFEROUS FOSSILS OF IRELAND. 23

Genus NAUTILUS.

Gen. Ch._—Shell convolute, discoid; septa simple at their edges, concave outwardly; siphuncle discon-
tinuous, usually central; aperture large, sinuate at the dorsal margin.

There are several subgeneric types in even the genus as here restricted, but of these we shall take for the
present no notice; most of the Palseozoie species have the spire exposed in all its turns by a large umbilicus,
while there are others in which the whorls are completely concealed by the last volution, such, for instance, as
the N. dorsalis.

NAUTILUS CycLostomus. Phil.
Nautilus cyclostomus. Phil. Geol. York.

Sp.Ch.—Apex spirally incurved, last chamber disjoined ; nearly straight conic; mouth and section of the
whorls circular; septa with a slight retral wave on the back; siphuncle nearly dorsal; surface smooth, or
marked with faint transverse sigmoidal strie.

This curious fossil approaches the genus Hortolus in structure, having the last whorl disjomed from the
rest, and produced nearly in a straight line ; it is rather a rare species.

Nautiwus Dorsaus. Phil.
Nautilus dorsalis (var. y.) Phil. Geol. York.

Sp. Ch.—Shell rapidly enlarging ; last chamber very large; mouth nearly circular, receiving the preceding
whorl at its ventral margin; umbilicus very small, rounded; septa about twelve in each turn; siphuncle
dorsal ; surface rugose.

There are three varieties of this magnificent shell mentioned by Professor Phillips, but as yet I have only
seen the one above mentioned ; the surface is perfectly smooth in the most ordinary state of preservation, or
when a portion of the outer shell is deficient. A specimen in the Collection of the Royal Dublin Society has
a portion of the shell perfect, shewing it to be marked with small, rough, irregular, transverse wrinkles. The
back is rounded, and the whole outline much resembles that of the recent Nautilus pompilius. Greatest dia-
meter five and a half inches, thickness of whorls three and a half inches. (Small specimen).

Nautitus gontotosus. Phil.
Nautilus goniolobus. Phil. Geol. York.
Sp. Ch.—Subglobose, smooth, whorls concealed ; umbilicus very small, rounded; septa with a deep retral
wave on the back, and an angular lobe on each side.
Ihave only seen a very imperfect specimen of this species. It is evidently not a true Nautilus, but I
hesitate to place it elsewhere, not having seen perfect specimens.

BetLeroruon. Montfort.

Gen. Ch.—Globose, involute, monothalamous ; last whorl embracing the others; a deep sinus in the mid-
dle of the outer lip, from which a band passes round the whorl, forming a kind of keel; surface transversely
striated.

The present genus differs remarkably from the other testaceous Cephalopoda, with the exception of Argo-
nauta, in having no chambers, and in the deep sinus which exists in the lip ; from Argonauta it differs m the
greater thickness of the shell, and more involute form, and the distinctly marked inner lip found in most of the
species ; these characters are also quite incompatible with the station assigned to it among the Heteropoda, by
modern writers; I am not aware on what grounds it has been associated with the Gasteropoda by Professor
Fleming. The genus occurs in the upper and lower Paleozoic rocks.

24 SYNOPSIS OF THE CHARACTERS OF THE

BELLEROPHON APERTUS. Sow.
Bellerophon apertus. Sow. Min. Con.—Bellerophon apertus. Phil. Geol. York.

Casts of the Bellerophon apertus, Sow., such as that figured in the Min. Con., are very common at Carling-
ford; they are spherical, with the whorls slightly exposed in an umbileus, which closed when the shell is per-
fect; the back is depressed.

BELLEROPHON CORNU ARIETIS. Sow.
Bellerophon cornu arietis. Sow. Min. Con.—Bellerophon cornu arietis. Phil. Geol. York.

Sp. Ch.—Involute, slightly compressed, carinate; whorls widely separated, entirely exposed; aperture
expanded; an acute sinus in the middle of the outer lip.

I have only seen imperfect specimens of this species; the shell is very thick, and the whorls are disjoined,
even when perfect.

BELLEROPHON CosTATuS. Sow.
Bellerophon costatus. Sow. Min. Con.—Bellerophon costatus. Phil. Geol. York.

Sp. Ch.—Central band convex, undefined ; surface with sharp, slender, transverse arched ridges ; umbi-
licus small, rounded.

This species is much narrower than the B. hiulcus, having, in fact, a subcarinated appearance; the dorsal
band is convex, and not defined on the sides by ridges or furrows; the transverse strie are fewer or farther
apart than in the B. hiulcus, which is also wider, and has a much broader, defined band.

BELLEROPHON HIULCUS. Mart. spP.

Nautilites hiuleus. Martin, Pet. Derb.—Bellerophon hiuleus. Sor, Min. Con.—Bellerophon hiuleus. Phil. Geol.
York.
Sp. Ch.—Width of the mouth exceeding the diameter of the shell, central band broad, flat, and defined
by a sharp elevated line on each side; surface sharply striated transversely ; umbilicus very small.
This is wider in proportion than any of the other species of Bellerophon; it is also distinguished by the
flat, defined, and very broad keel; the transverse striz are sharp, prominent, and arched, as is usual in this
genus. Diameter two inches, thickness two and a half inches.

BELLEROPHON L&VIS. M‘Coy. (PI. IL fig. 1).

Sp. Ch.—Globose, very wide, smooth, band narrow, flat, not prominent, defined on each side by an im-
pressed line.

This species bears some resemblance to the B. hiuleus in general form, but is at once distinguished by
its smooth surface and narrower band; the aperture is greatly expanded at the sides, its width being two and a
half times its length; the umbilicus is so shallow that it can hardly deserve the name; it is, however, defined
on the last whorls by an obtuse keel. Diameter one inch six lines, width of the mouth one inch six limes.

BELLEROPHON OBSOLETUS. M<Coy. (PI. IL fig. 3).

Sp. Ch.—Globose, slightly compressed towards the back; keel convex, but undefined; surface almost
smooth, with crowded, nearly obsolete, arched, transverse strie.

In general form, and in the obtuse, undefined, dorsal band, this species closely resembles the B. costatus
Sow., with which I at first confounded it; the present shell is, however, distinguished by the absence of the
distant, prominent, sharp, concentric ridges of that species, the surface being nearly smooth, marked only by
very faint, obsolete, transverse striz. Diameter eleven lines, thickness ten lines.

CARBONIFEROUS FOSSILS OF IRELAND. 25

BELLEROPHON RETICULATUS. M‘Coy. (PI. IL fig. 2).

Sp. Ch.—Orbicular, compressed, umbilicus deep, rounded at the edges; keel obtuse, rounded ; surface reti-
culated by equal spiral and curved transverse striz, forming small tubercles at the intersections.

T have taken Professor Phillips’ authority (Geol. York) for the axis of the B. decussatus of Fleming being
solid, which, therefore, differs from the present species, which is distinctly umbilicate; the transverse striz are
also more obtuse in the present shell, and are equal in thickness to the spiral ridges. By this latter character
fragments of the two species may be distinguished. Diameter three lines, thickness two and a half lines.

BELLEROPHON TANGENTIALIS. Phil.
Bellerophon tangentialis. Phil, Geol. York.

Sp. Ch.—Central band sharp, narrow, prominent ; surface with transverse strie, which form tangents to
the umbilicus, and are perpendicular to the keel.

The band of this species forms a compressed, prominent keel, and is distinguished from the other species
by the transverse strix being perpendicular to it (in the others they meet it at a more or less acute angle),
and by their forming tangents to the edge of the umbilicus, which is large and rounded. Diameter one inch
two lines, thickness one inch.

BELLEROPHON TENUIFASCIA. Sow.

Conch. naut. hiuleus, var. c. Martin, Pet. Derb.—Bellerophon tenuifascia. Sow. Min. Con.—Bellerophon tenuifascia.
Phil. Geol. York.
Sp. Ch.—Band very narrow, elevated, threadlike ; transverse striz very fine; umbilicus moderate.
The fineness of the transverse striz, and the very small, threadlike band, distinguish this from any other
of the genus; the umbilicus is rather large and rounded. Diameter one inch seven lines, thickness two
inches.

BELLEROPHON WENLOCKENSIS. Sow. (?)
Bellerophon Wenlockensis. Phil. Pal. Fos.

A single cast of a small specimen, apparently of this species, has occurred. It is almost impossible, how-
ever, to identify internal casts of this genus with specimens in a perfect state. I have given this reference for the
Insh specimen, rather because it agrees perfectly with the small Devonian cast which Professor Phillips provi-
sionally placed with this species, than from a conviction that it is identical with the Silurian shell.

Evrnemus. MM‘ Coy’.

Gen. Ch.—Globose, involute, monothalamous; surface spirally striated; no dorsal band.

Under this name I have separated those beautiful little shells hitherto ranked with Bellerophon, but desti-
tute of the dorsal band or keel characteristic of that genus; the sculpturing of the surface of the two genera is so
distinct, that even fragments of them can in general be discriminated; the strie or furrows on the surface of
Bellerophon are invariably transverse or parallel with the edge of the lip, while in Euphemus they are always
spiral, following the direction of the whorls ; a few reticulated species seem to unite the groups, which, taken
on the whole, are distinct.

They are all of much smaller size than the true Bellerophons.

* One of the Argonauts.
G

26 SYNOPSIS OF THE CHARACTERS OF THE

BELLEROPHON (EUPHEMUS?) GLOBATUS. Sow. SP.

Bellerophon globatus. Sow. Sil. Syst. ? and Geol. Trans.—Bellerophon globatus. Phil. Pal. Fos.

A few very obscure casts of a minute globular Bellerophon, with a pervious umbilicus, have been provi-
sionally referred to this species; they are identical with those of N. Devon, which Professor Phillips has also
provisionally ranked with this Silurian species.

BELLEROPHON (EupHEMuS) INTERSECTUS. M‘Coy. (PI. IIL fig. 10).

Sp. Ch.—Globose, umbilicate, aperture expanded, outer lip very slightly bilobed; back rounded, spirally
marked with distinct rounded ridges, intervening spaces flat, crossed by delicate transverse striz, slightly re-
troflexed on the middle of the back.

This beautiful little shell is easily distinguished from the Bellerophon decussatus, or rather, perhaps, B.
striatus of Fleming, which it most resembles, by the want of a band; the reticulation is also coarser. Diameter
one and a half lines.

BELLEROPHON (EuPHEMUs) orBicuLus. JM‘Coy.

Sp. Ch—(From the casts) globose diameter one fifth less than the width; smooth; spire of three whorls,
which are exposed in a very narrow, rounded umbilicus, whorls increasing rapidly in size; back broad,
rounded ; mouth arched, twice as wide as long, sides rounded; shell very thin.

This species differs from the casts of the B. wrii, and B. globatus, in the shortness and width of the
mouth, and in the more broadly rounded back, its form being almost’ identical with that of the B. D’ Orbignii
(Portk.), from which it differs in its very thin shell, and smooth surface, even the casts of that species being dis-

tinetly suleated. Diameter of large specimens five lines.

BELLEROPHON (EupHEemus) Uru. Fem. sp.

Bellerophon Urii. Vem. Brit. Anim.—Bellerophon Urii. P#il. Geol. York.—Bellerophon Urii. Porth. Geol. Rep.—
Bellerophon D’Orbignii? Portk. Geol. Rep.
Sp. Ch.—Globose; mouth expanded; umbilicus imperforate; surface with numerous, spiral, narrow,
rounded ridges, separated by smooth, concave furrows.
This species, so common in the Glasgow coal fields, occurs occasionally in the Irish carb. limestone; the
regular spiral ridges are very characteristic of the species; the furrows are somewhat wider than the ribs they
separate. Diameter half an inch, thickness half an inch.

PTEROPODA,

ConuLARIA QUADRISULCATA. Sow.

Conularia quadrisuleata. Sow. Min. Con.

I have seen one imperfect large specimen from the Kildare limestone, which seemed to be of this species,
although larger, and tapering more gradually than the Coal Brook Dale specimens. This specimen has very
strong longitudinal furrows at the four angles, but the furrow down the middle of each of the faces is very
slight. Although the surface is obviously marked with strong transverse ridges, which meet at an obtuse angle
in the centre of each of the sides, yet the specimen is too imperfect to determine any thing farther.

CARBONIFEROUS FOSSILS OF IRELAND. 27

GASTEROPODA.

The modern tribe Pectinibranchiata includes all those molluscs whose body is covered by a spiral univalve
shell; they have the head distinctly marked and provided with eyes and tentacula, and the under surface of
the body formed into a dise-like foot for walking. The tribe is divisible into the following groups:

First, the Zoophaga of Lamarck, or the carnivorous shell-fish: these are among the most highly organized
of the Gasteropoda; they have a distinct head, furnished with two tentacula, and perfectly formed eyes.
Their shells are distinguished from the other univalves by having a deep notch or canal at the base of the
aperture, which serves as a protection to the respiratory siphon of those animals. Of this group there
are very few examples to be found in the mountain limestone; and these, I think, chiefly belong to the
family Fusing ; the numerous shells, called Buecinum by geologists, not belonging to that group, inasmuch
as their base is never truncated; they would rather approximate to the genus Chrysodomus or Macrocheilus,
in which the general form is buccinoid, and the basal channel is always shorter than the spire. To this
group also belong those shells formerly described as Melania (but now separated from that fresh-water genus
by Professor Phillips, under the generic name of Loronema) ; they are analogous in the present group to
the Turritelle among the Phytophaga.

The next group is the Phytophaga. These are less constant in their characters than the last, but the
greater number live upon vegetables, and have the aperture of the shell entire, or wanting the notch of the car-
niyorous group.

The Phytophaga, or plant-eating Gasteropods, include nearly all the univalve shells of the Paleozoic rocks ;
all those belonging to the genera Plewrotomaria, Turbo, Turritella, and Euomphalus, being clearly of this
tribe ; a satisfactory proof of the abundance of fuci or sea-weeds at these periods, although their remains are not
found in the fossil state. As the animals of this division have no respiratory siphon, the shells are easily dis-
tinguished from those of the carnivorous Gasteropods by the latter having the base deeply notched to allow the
exit of the respiratory tube, while those of the present tribe, being destitute of that organ, have the aperture
round and entire; they are all spiral, turbinated shells, which at once distinguishes them from the Scutibran-
chia, or the limpets (Cyclobranchia) with which many authors confound them. One anatomical fact of impor-
tance to the fossilist seems to have been entirely overlooked, namely, that the sexes are distinct and in diffe-
rent individuals, the female shells having the body whorl invariably more ventricose than in the male specimens,
so that if unacquainted with the structure of the animals, one might be led to describe the sexes as distinct
species. The majority of the mountain limestone shells belonging to this group appear to enter into the family
Turbide, or that family which connects the Phytophagous with the Zoophagous Gasteropods, these animals
exhibiting much of the structure of the carnivorous type, while their shells are strictly those of the Phytophaga,
another instance of the importance of attending to the anatomy of the creatures, as the mere conchologist might
lead to error, by denying the existence of carnivorous shells, at periods when they might have been abundant,
the popular idea being that every carnivorous shell must have a notch for the respiratory tube; it is, however,
well known that a number of recent shells of this group have the base of the shell entire, although the animal is
carnivorous.

After the Pectinibranchiata we have the Scutibranchia, which are known at once from the last by their
funnel-shaped shells, which are scarcely ever spiral.

The next group is the Cyclobranchia, or limpets and chitons, the first having a simple cup-shaped shell,
and the other one formed of eight transverse, imbricating, shelly plates, scarcely ever found in the fossil
state.

Next we have the Tectibranchia, or Bullas, whose mantle forms two fin-shaped lobes, by which they can
swim with facility: they form the passage to the Cephalopoda.

The remaining groups are not interesting to the Paleontologist.

28 SYNOPSIS OF THE CHARACTERS OF THE

Macrocuetuus. Phil.

This name has been proposed by Professor Phillips for those shells of the carboniferous limestone pre-
viously called Buccinum. 'To that genus of course they do not belong, as their base is not notched. Such
species as the M. sigmilineus, M. elongatus, &c., seem referrible to the recent genus Chrysodomus, of which
the Fusus antiquus of our coasts is the type; and including those bucciniform shells, which have the base pro-
duced into a channel shorter than the spire ; the whorls ventricose; the outer lip thin, and the inner lip obso-
lete; those fossils were, therefore, most probably carnivorous, like the Fusing just mentioned, although the

aperture is entire.

MACROCHEILUS ACUTUS. Sow. SP.
Buccinum acutum. Sow. Min. Con.—Buccinum acutum. Phil. Geol. York. (?)

Sp. Ch.—Acutely conical, smooth; volutions numerous; spire longer than the aperture.
This is a very elegant species; the spire is composed of five or six convex whorls, the body whorl small
and contracted at the base, surface smooth. Length one inch eight lines, Diameter of body whorl nine

lines.

MACROCHEILUS CANALICULATUS. JM/‘Coy. (Pl. V. fig. 1.

Sp. Ch.—Ovate; spire acute, turriculated, composed of five flat whorls, channeled at the sutures ; body

whorl as long as the spire, convex; surface smooth.
This pretty species is remarkable for the flatness of the whorls of the spire, and the channeled sutures.

Length five lines, width of basal whorl three lines.

MacrocHemius curvitineus. Phil. sp.
Buccinum curvilineum. PAz/. Geol. York.

Sp. Ch.—Very elongate; volutions broad, slightly convex, obscurely striated; spire twice the length of the

aperture.
This species has the body whorl very little larger than that which precedes it; the spire is very long,

although of comparatively few turns, the width of each volution equalling the diameter of the shell at that part;
the transverse striz on the volutions are very oblique, and somewhat curved, whence the name. Length one

inch five lines; diameter seven lines.

MAcROCHEILUS IMBRICATUS. Sow. sp.
Buccinum imbricatum. Sow. Min. Con.—Buccinum imbricatum. Phil. Geol. York.

Sp. Ch.—Ovate ; spire shorter than the aperture; volutions convex, with very fine, transverse striz.
Very nearly related to the M. acutus, but less elongate, and having the body whorl larger in proportion to
the spire. Length one inch seven lines; diameter of body whorl ten lines.

Macrocueitus Fimpriatus. MCoy. (Pl. V. fig. 2).

Sp. Ch.—Ovate, ventricose ; spire equal in length to the last volution, of three or four rounded whorls; all
the sutures strongly fringed or crenated; whorls crossed by fine, sigmoidal striz.
This minute species has the sutures very strongly crenated. Length one line; width half a line.

CARBONIFEROUS FOSSILS OF IRELAND. 29

Macrocuettus ovatus. AMCoy. (PI. V. fig. 3).

Sp. Ch.—Oval; spire short, of three convex whorls; pillar lip flattened; base attenuated; surface smooth.

This species is allied to the Buccinum imbricatum (Sow.), but is distinguished from it by the shorter spire,
the broad, distinctly flattened pillar, and the lengthened, slender base; the outer lip is entire, thin, and without
a notch at the base; the volutions are all convex, with simple sutures. The flattened pillar approximates this
curious species to the genus Littorina, but the prolongation of the base of the shell induces me to place it rather
in this group ; it is interesting, however, as indicating the passage from one genus to the other. Length ten
lines; width seven lines; length of the mouth six lines.

MACROCHEILUS PARALLELUS. Phil. sp.
Buccinum parallele. Phil. Geol. York.

Sp. Ch.—Elongate, turreted; volutions convex; upper third of each whorl flattened, and finely striated
spirally ; lower portion with very coarse, spiral sulci.

This well marked species occurs but very rarely; the smallest fragments are easily recognized by the dis-
similarity of the upper and lower parts of each whorl.

MAcROcHEILUS RECTILINEUS. Phil. sp.
Buccinum rectilineum. Phil. Geol. York.

The specimens I have seen of this shell only differ from the M. imbricatus, in having the turns of the
spire slightly more tumid, and in the lines of growth being less oblique, and not sinuous.

MAcROCHEILUS SIGMILINEUS. Phil. sp.
Buccinum sigmilineum. Phil. Geol. York.

Sp. Ch.—Elongate, hemifusoid; whorls ventricose; mouth and spire equal in length; outer lip and lines
of growth thin, oblique, slightly sigmoid.

This fine species seems congeneric with the Fusus antiquus of our coasts, which forms the type of the
modern genus Chrysodomus. I have only seen a few imperfect specimens.

Macrocueruus tricinctus. M‘Coy. (Pl. V. fig. 4).

Sp. Ch.—Globose; spire very short, acute, of three smooth, convex whorls; body whorl large, tumid,
upper half smooth, lower half girt with three strong, spiral sulci.

This little species is remarkable for the spiral ridges being placed so low down on the basal whorl, that
they are conc ealed on the spire by the suture, leaving that part of the shell smooth. Length one line;
diameter one line and a quarter.

Loxonema. Phil.

Gen. Ch.—Shell spiral, elongate; mouth elongate, effuse below, right lip thin, waved; inner lip obsolete ;
no umbilicus; surface with arched, prominent stria.

A provisional genus established by Professor Phillips for the reception of those elegant Palaozoic fossils for-
merly described as Melania, Turritella, &e. Although the characters of the genus are rather indefinite, yet
by its adoption we avoid the serious error of including so many recent genera in the older rocks. It is here
considered as a sub-genus of Macrocheilus.

H

30 SYNOPSIS OF THE CHARACTERS OF THE

LoxoneMa BREVIS. M‘Coy. (PI. III. fig. 2).

Sp. Ch.—Elongate, ovate ; spire obtuse, of five, gradually increasing volutions ; whorls slightly convex, with
rather distant, strong, slightly arched, longitudinal ridges, thickest and most prominent below, originating in a
small tubercle above; basal whorl very little larger than the preceding one.

Differs from the Z. rugifera in the short form and less number of whorls, and from the Devonian var. of
LL. tumida in the flatness of the whorls, and stronger sulci. Length three and a half lines, width one and a
half lines.

Loxonema constricta. Mart. sp.

Melania constricta. Sow. Min. Con.—Melania constricta. Phil. Geol. York.—Loxonema tenuistriata. Porth. Geol. Rep.

Sp. Ch.—Smooth, whorls tumid below, constricted above, sutures crenulated.

The constricted form of the upper part of each whorl, and the strongly plaited sutures, distinguish this spe-
cies from its congeners; the latter character, however, is rarely well seen. Captain Portlock’s L. tenwistriata
does not seem to differ from the ordinary state in which specimens of this species are found. Length two inches
six lines, diameter of last whorl nine lines.

LoxoneMA IMPENDENS. J/‘Coy. (PI. IIL fig. 3).

Sp. Ch.—Turreted, elongate, smooth; spire of about nine or ten, gradually increasing whorls; volutions
flat above, very tumid, and obtusely rounded below; sutures plain, very slightly imbricating ; surface smooth.

This fine shell differs from the Z. constricta, in its pla (not crenated) sutures, the sutures not being
constricted, and the greater prominence of the whorls below; from the Z. sudculosa, Phil., in the smooth sur-
face, and from the ZL. swturalis, Phil., in the sutures not being prominent. Length about two inches five lines,
diameter of basal whorl one inch.

The specimen figured was obligmgly communicated by Mr. Newenham, of Cork.

Loxonema potyeyrA. M‘Coy. (Pl. UL fig. 1).

Sp. Ch.—Very elongate, slender; spire of eleven, very convex, gradually increasing whorls, each marked
by five strong spiral ridges.

This beautiful little shell is remarkable for its small size and very attenuate form; the volutions are more
numerous than in the other species. From the Z. acicula, Phil., it is known by the greater number of the
spiral ridges. Length three lines, diameter half a line.

LoxoneMA PULCHERRIMA. M‘Coy. (PI. VIL fig. 7).

Sp. Ch.—Very much elongate, volutions numerous, flattened, crossed by sharp sigmoidal sulci, deepest at
the upper edge; mouth twice as long as wide.

This beautiful species is distinguished from the L. nexilis by the greater curvature and sharpness of the
striez; the volutions are flattened, numerous, their length and breadth about equal. The mouth in the speci-
men figured is very perfect.

LoxoNnEMA sutcaTuLA. M‘Coy. (PI. V. fig. 6).

Sp. Ch.—Elongate; spire acutely conic, of seven convex whorls, each girt with about ten equal, spiral
sulci.

This shell is distinguished by the great number of its spiral sulci. Length five lines and a half; diame-
ter of basal whorl two lines and a half; height of basal whorl two lines.

CARBONIFEROUS FOSSILS OF IRELAND. 31

LoxoneMA sutcutosa. Phil. sp.
Melania sulculosa. Pl. Geol. York.

Sp. Ch.—Elongate; whorls convex, crossed by arched stria, more strongly marked towards the basal
suture.

This is one of the largest known species, frequently attaining six inches in length; it is more elongate than
the rest, and is moreover remarkable for the strong, waved sulci on the volutions, which very nearly resemble
those of the Z. newilis of the Devonian rocks. Length three inches; diameter of basal whorl one inch three lines.

Loxonema Tumips. Phil.
Melania tumida. P27. Geol. York.—Loxonema tumida. P/7/. Pal. Fos.

Sp. Ch.—Pyramidal, short ; volutions narrow, very convex, crossed by direct, simple striz.
- . che . . . . - . .
This species is distinguished by its rapidly tapering form, and narrow, very convex volutions, which are
about eight in number; each whorl is about twice as wide as long. Length one inch six nes; diameter of
basal whorl ten lines.

Loxonema TurRITA. M‘Coy. (PI. V. fig. 7).

Sp. Ch.—Obliquely conical, turreted ; spire composed of four or five rapidly increasing whorls; whorls
cylindrical, or flat on the sides, and broadly tabulated above, the two portions separated by a sharp angle;
whorls longitudinally costated with broad, close, rounded ridges, crossed by very fine, sharp, spiral striz.

This beautiful species does not particularly resemble any Grasteropod of this or the allied genera. Length
two lines.

TurriteLtta. Lam.

Gen. Ch.—Shell elongate, subulate ; whorls very numerous, in general spirally grooved ; mouth round,
lips thin; united anteriorly.

TURRITELLA MEGASPIRA. M‘Coy. (PI. V. fig. 5).

Sp. Ch.—Subulate, very elongate; whorls about sixteen or seventeen, flat, smooth, slightly rounded at
the sutures; tip of the spire obtuse.

This species is chiefly remarkable for its length, and the great number of its whorls. The dotted restora-
tion in the plate is considerably too long, as I find from perfect specimens that the spire does not come to a point,
but, though composed of an extraordinary number of whorls, it is blunt, and obtusely rounded, resembling that
beautiful Brazilian land shell, the Megaspira Ruschenbergiana. The whorls are flat, or very shichtly convex,
slightly impressed at the sutures; surface perfectly smooth. Diameter of basal whorl six lines ; length of an
imperfect specimen of nine whorls one inch ten lines.

TURRITELLA suTURALIS. Phil.
Turritella suturalis. Phil. Geol. York.
Sp. Ch.—Conical, smooth; whorls flat, or slightly concave; sutural, and lower edges rounded, pro-
minent.

This species is rendered very remarkable by the prominent, rounded edges of the whorls. Diameter of
last whorl seven lines; length one inch two lines.

32 SYNOPSIS OF THE CHARACTERS OF THE

TURRITELLA TENUISTRIA. Phil.
Turritella tenuistria. Phil. Geol. York.

Sp. Ch.—Acutely conical; whorls flat, slightly angulated below; surface with very fine, oblique, and
spiral striz.

This abundant species is easily recognized by its conical, tapering form, and plain, slightly striated volu-
tions. Length one inch six lines; diameter at base seven and a half lines.

Turso. Linn.

Gen. Ch.—Turbinate, ventricose ; spire pointed ; aperture round, entire ; base convex.

Turso sprrata. M‘Coy. (PI. V. fig. 29).

Sp. Ch.—Ovate; spire lengthened; acute, conic of about five slightly convex whorls; basal turn, small,
ventricose, rounded, imperforate; aperture ovate, rounded anteally ; pointed retrally, rather more than half the
length of the shell.

Only casts have as yet occurred of this species, which differs from the Buccinum imbricatum, Sow., in the
small size of the basal whorl, and greater length of the spire, and number of the volutions. Length one inch
and, probably, seven lines; diameter of last whorl one inch three lines; length of the mouth eleven lines.

Lirrorina. Fer.
Gen. Ch.—Turbinate; spire small, accuminated; aperture large, rounded anteally; outer lip sharp ; pil-
lar lip flattened.
The recent Littorine, as their name implies, are found chiefly on the shores, or in shallow water, where
they feed on the sea-weeds.

Lirrormna pusitLA. M*Coy. (PI. V. fig. 26).

Sp. Ch.—Ovate, short; spire small, sharp, of three convex whorls; surface smooth; mouth rounded an-
teally, narrowed retrally.

This is one of the smallest species of the genus found in the Carb. limestone; the spire forms rather less
than a third of the length of the body whorl; all the whorls are convex, and the surface quite smooth.
Length three lines, width two lines and a quarter.

Lacuna. Turt.

Gen. Ch.—Shell globose, thin; body whorl large, ventricose ; spire very small, pointed, of few, rapidly in-
creasing whorls; aperture semicircular; columella oblique, the upper part reflected over the umbilicus, which
forms a lengthened groove behind the columella.

Lacuna antiqua. MCoy. (PI. V. fig. 24).

Sp. Ch.—Depressed; volutions rounded; spire very small, acute, of three rapidly enlarging whorls; um-
bilicus very large, sharply defined; inner lip slightly reflected over it above, oblique; aperture large, semicir-
cular; surface very finely striated across the volutions.

This curious little shell seems to be the first instance of the genus Lacuna occurring in the older deposits.
The drawing has been injured in the lithographing. Length two lines, diameter three lines.

CARBONIFEROUS FOSSILS OF IRELAND. 33

Narticorsis. JZ Coy.

Gen. Ch.—Shell globose; inner lip smooth, flattened, slightly thickened; spire very small; umbilicus
none.

Tn this genus are included several fossils of the carboniferous limestone, provisionally placed by the late
Mr. Sowerby, Professor Phillips, and others, in the genera Ampullaria, Natica and Nerita. From Natica and
Ampullaria it is distinguished by the want of an umbilicus, and the flattened pillar; from the latter genus it
also differs, in being a marine shell; the smooth inner lip distinguishes it from Nerita. The operculum
which I have seen two or three times, is quite distinct from that of Natica or Nerita, as will be seen by a
glance at the figure, Pl. III. fig. 9, which is from a specimen presented by Mr. Newenham, of Cork.

Naticopsis CANALICULATA. M*Coy. (Pl. VIL fig. 3).

Sp. Ch.—Globose; body whorl large; spire depressed of three inflated whorls; sutures deeply channeled ;
mouth slightly dilated; shell very thin; volutions delicately striated across.

The thin shell, and channeled sutures of the spire, in this species, remind us strongly of Ampullaria. The
spire is rather larger than is usual in this genus, and though depressed, the whorls are remarkably convex; the
deeply canaliculated suture distinguishes it from all others of the genus.

Naticopsis pusia. M‘Coy. (Pl. VII. figs. 2 and 2a).

Sp. Ch.—Transversely ovate, very much depressed ; spire of three rather convex whorls; mouth trans-
versely ovate; surface smooth; base convex.

I have seen only one specimen of this curious species; it is more depressed than any other of the genus ;
length ten lines, width two and a quarter inches.

NATICOPSIS ELONGATA. Phil. sp.
Natica elongata. Phil. Geol. York.

Sp. Ch.—Elongate, very obliquely oval; spire prominent, mammillary, of two imperfect volutions; sur-
face with very delicate, oblique striz.

This species is remarkably elongate in form; the spire is almost wholly exserted; the surface is smooth,
with the exception of some very fine lines of growth. Length two inches, diameter one inch three
lines.

Naticopsis NeritowwEs. M<Coy. (PI. V. fig. 25).

Sp. Ch.—Globose, smooth; length one-fourth less than the width; spire very small, flat, of two whorls;
aperture large, semicircular; outer lip thin; inner lip perfectly straight, thickened, convex.

This little shell, by its general form, minute spire, straightness of the inner lip, and large, semicircular
aperture, approaches the true Nerita, Linn., so closely, that we might include it in that genus, were it not
for the absence of any teeth on the pillar, which, besides, is slightly convex and thickened, as in Naticopsis,
M‘Coy; it is, therefore, better to include it in the fossil genus I have already established for shells having this
peculiar character of columella, while the specific name will indicate the analogy I have pointed out. Length
two and a half lines, width three lines.

Naticorsis Parisi. MCoy. (PI. II. fig. 9, and Pl. VI. figs. 4a and 4b).
Natica elliptica? Phil. Geol. York.
Sp. Ch.—Body whorl large, obliquely oval; spire very small, depressed, of four convex turns; surface
perfectly smooth, except at the sutures, which are elegantly marked with sharp, short strie; inner lip very much
thickened; convex above, flattened or concave below.

I

34 SYNOPSIS OF THE CHARACTERS OF THE

NaTIcopsis PLICISTRIA. Phil. sp.
Natica plicistria. Phil. Geol. York.
Sp. Ch.—Ovate; spire prominent, of three volutions, slightly concave at the sutures, where they are
strongly striated; surface with fine, oblique striz.
This is easily distinguished from the N. Phillipsii, by its prominent spire and ovate form; it is a much
scarcer species; the plication of the sutures appears to be the remains of delicate membranaceous plaits, such as
we see in many of the Halotide.

NATICOPSIS SPIRATA. Sow. SP.
Nerita spirata. Sow. Min. Con.
Sp. Ch.—Globose, obliquely compressed ; spire flattened, of three turns; volutions sharply striated across ;
striz rising into a sharp plication at the sutures.
This pretty little species was originally described by Mr. Sowerby as a Nerita ; but from the flattened,
smooth, arched, inner lip, it must belong rather to the present genus. The Silurian fossil of this name seems a
perfectly distinct species. Diameter ten lines; length eight lines.

EvoMPHALUS. Sow.

Gen. Ch.—Discoid; spire depressed, or elevated, of many slowly increasing whorls; dextral; whorls entirely
exposed by the very large umbilicus; surface generally smooth, or destitute of spinous processes.

The genus Skenea of Fleming does not appear to me to differ materially from the previously proposed
genus Euomphalus, especially if extended, as Professor Fleming has done, to those fossils; it would be a more
definite and better genus if restricted to the recent shells of which the Serpula cornea, Adams, is the type.
Cirrus differs in nothing except that its spire is more or less produced, a character so vague and variable as to
be of no use as a generic distinction, and I have therefore rejected Skenea as applied to the fossil species, and
merged Cirrus into Euomphalus, knowing of no character by which to distinguish them; at the same time I am
perfectly aware that Euomphalus, as it now stands, requires division; thus those species with rounded whorls,
and a circular entire mouth, should obviously be separated from those in which the whorls are angulated, and
in which there is a slit in the outer lip, as in Schizostoma. They resemble Lamarck’s Delphinula in the de-
pression of the spire, its obtuse tip, and the great size of the umbilicus, as well as in the absence of the pillar;
differing principally in the smoothness of the surface.

EvompHatus acutus. Sow. sp.
Cirrus acutus. Sow. Min. Con.—Cirrus acutus. Phil. Geol. York.
Sp. Ch.—Acutely conical; volutions very convex, with a flat space on the upper part of the lower ones;
body whorl much larger than the preceding ones.
The lower basal turn is almost discoid, closely resembling an Ewomphalus pentangulatus in form; but the
whorls from thence to the tip form an acutely conical spire. Diameter one inch six lines; height one inch three

lines; thickness of last whorl six lines. Some specimens from Little Island, Cork, measure three inches in dia-
meter.

EvompHaLus mQuaLis. Sow. sp.
Planorbis xqualis. Soe. Min. Con.—Skenea xequalis. Mem. Brit. Anim.

Sp. Ch.—Discoid; equally concave on both sides; whorls fully exposed; an obtuse keel on the right
side; left side bicarinate; mouth circular.

This species might, perhaps, be retained under the genus Skenea, as it appears more nearly allied than
any of the other fossil species to the recent Serpula cornea, Adams, and Helix serpuloides, Mont., forming the
type of that genus; it is very local. Diameter six lines.

CARBONIFEROUS FOSSILS OF IRELAND. 35

Evompnatus Ancuis. M‘Coy. (PI. IL. fig. 11).

Sp. Ch,—Discoid ; depresso-conical ; height of the spire equal to half the diameter, composed of five or six
rounded whorls, very gradually increasing, the last whorl very slightly exceeding the preceding one in diame-
ter; mouth round; umbilicus very wide, exposing all the whorls; surface smooth, with fine, irregular lines of
growth, which bend forward in passing over the circumference.

The whorls of this species increase much less rapidly in size than in the Z. rotundatus, or E. acutus, the
last turn being very little larger than the preceding one, it is also much less elevated than either of those species ;
from the former, in particular, it differs in the small size of the basal whorls, and a slight flatness on their
upper part, which, at the same time that it makes them more nearly circular in the section, produces a very
obtuse keel, or convexity, on the upper part of the circumference, which is also marked by a slight retroflexion
of the lines of growth, as in Schizostoma, the strie of E. rotundatus are directly across. From the E. aeutus it
differs in the small size of the last whorl, obsolete keel, and depressed form. Diameter one inch eight lines ;
height of spire ten lines; height of mouth five lines.

EvomPHatus Birrons. Phil.
Euomphalus bifrons. Phil. Geol. York.

Sp. Ch.—Spire depressed, whorls very convex, obtusely carinated beneath, and bearing one spiral row of
large, nodular tubercles above.

The spire of this species is composed of about five turns, very convex both above and below; beneath they
are obscurely carinated, as in the EZ. pentangulatus, but above they are ornamented with a row of large, obtusely
rounded tubercles, about sixteen in a turn; they are about their own diameter apart. Diameter one inch seven
lines, thickness six lines.

Evompuatus catyx. Phil.
Euomphalus calyx. Phil. Geol. York.

Sp. Ch.—Spire flat above; back very broad, flat; umbilicus deep, conical, margined by a sharp keel.

This curious species has the back very broad and flat, so that, although the spire is not raised, the umbili-
cus is very deep; the flat, steep sides of the umbilicus meet the back at an acute angle, so as to form a sharp
keel round the base of the shell; the upper surface resembles that of the Z. catillus. Diameter one inch, thick-
ness five lines. It grows much larger.

EUOMPHALUS CATILLUS. Mart. sp.
Helix catillus. Mart. Pet. Derb.—Euomphalus catillus. Sow. Min. Con.—Euomphalus catillus. Phil. Geol. York.

Sp. Ch.—Spire concave, above; whorls with a very sharp keel both above and below, near the outer edge,
back broad, but slightly convex.

This species is much rarer than the E. pentangulatus, from which it differs chiefly in having the keel on
the under side of the volutions, at least as sharp as that on the upper; both keels are nearer to the outer edge
than in that species, and the back is consequently broader and flatter; there are about the same number of
volutions in each. Diameter one inch three lines, thickness of last whorl six lines.

36 SYNOPSIS OF THE CHARACTERS OF THE

Evompuatus (Puanerotinus) cristatus. Phil. sp.
Euomphalus cristatus. Phil. Geol. York.—Phanerotinus cristatus. Sow. Min. Con.

An imperfect fragment of this singular shell has been obtained. It is easily known by its disjomed whorls,
and large, dentated, compressed, dorsal crest. The specimen in Mr. Griffith’s Collection must have been about
six inches in diameter.

EvompHatus croraLostomus. MCoy. (Pl. VII. fig. 4).

Sp. Ch.—Discoid, depressed; spire slightly raised, of five whorls ; a depressed or flattened space on the
top of each whorl, bounded by an obscure keel; back flattened, convex ; base flattened; umbilicus very large ;
mouth dilated ; surface with transverse irregular lines of growth.

This species occasionally reaches a foot in diameter; the spire is very slightly raised; the mouth, in old in-
dividuals, is dilated, bell-shaped (whence the specific name), the remains of the expanded margins giving a
peculiarly rugged aspect to the last whorl.

EvoMPHaLus ELonGATUS. M‘Coy. (PI. III fig. 12).

Sp. Ch.—Elongate, conic, spire acute, nearly equalling in height the diameter of the base; of five gradu-
ally increasing whorls; upper half of the volutions plane, lower half convex ; the two portions separated by an
obtusely rounded keel; surface smooth.

This species is distinguished from the E. acutus by its gradually increasing whorls, and from the EL. penta-
gonalis and Natica tabulata, as well as H. acutus, by the greater length and acuteness of the spire; it is also a

much smaller species than any of them. Length about three and a half lines, width of basal whorl two and a
half lines.

EvompuHatus marcinatus. M'‘Coy. (Pl. V. fig. 21).

Sp. Ch.—Discoid, spire depressed ; whorls convex below, flat or slightly concave above; upper surface of
the whorls bounded exteriorly or dorsally by an obtuse keel, which separates it from the back, and interiorly or
ventrally by a narrow tumid border. ;

The volutions are four or five in number, of the same form as the L. pentangulatus, from which the tumid,
prominent, inner margin of the whorls distinguishes it; it is also more strongly striated across. Diameter two
inches three lines, thickness of last whorl seven lines.

Evompuatus necuectus. M‘Coy. (PI. V. fig. 23).

Sp. Ch.—Spire very much depressed, formed of three rounded volutions; umbilicus wide, rounded, sur-
face smooth.

This shell has been figured by Professor Phillips, in Pl. XV. fig. 31, of the Geology of Yorkshire, where,
however, it is not described, being passed over in the explanation of the plates as a probable variety of the C.
rotundatus; from that species, however, it is at once distinguised by the very small number of whorls, and the
flatness of the spire, which hardly rises above the last volution; I have seen a considerable number of specimens
from different localities in Ireland, and in all I have seen, the characters were constant. Diameter three lines,
thickness of last volution one line.

CARBONIFEROUS FOSSILS OF IRELAND. 37

EUOMPHALUS PENTANGULATUS. Sow.

Euomphalus pentangulatus. Sow. Min. Con—Euomphalus pentangulatus. Phil. Geol. York.—Euomphalus Bronnii.
Portk. Geol. Rep.

Sp. Ch.—Spire flat above; whorls convex, very obtusely carinated beneath ; back very convex ; upper
portion of each whorl divided near the centre by a distinct, but not sharp, keel; that portion of the surface on
the outside of the keel is convex, that on the inside flat.

This very common shell has about five turns in the spire; the umbilicus is very wide, but shallow, the
spire being very slightly raised; the under portion of the whorls is very convex, and obtusely angulated in the
middle ; the back is slightly compressed; diameter two inches, height of spire nine lines, thickness of the last
whorl eight lines.

EUOMPHALUS PILEOPSIDEUS. Phil. sp.
Cirrus pileopsideus. Phil. Geol. York.

Sp. Ch.—Discoid, depressed ; spire scarcely elevated above the level of the basal whorl, composed of four
obtusely rounded, slightly imbricating whorls, rather coarsely striated across.

A few imperfect specimens have occurred of this species. Diameter seven lines, thickness of last volution
three lines.

EvoMPHALUS QUADRATUS. M'Coy. (PI. V. fig. 22).

Sp. Ch.—Discoid; spire flat, of three or four whorls; umbilicus very large, rounded ; whorls square, finely
striated across.

This little species is remarkable for the square form of its volutions; the spire is perfectly flat, as if trun-
cated; the back broad, and bounded by two distinct keels, between which it is flat, or very slightly convex.
Diameter six lines, length of mouth two lines, height of mouth two lines.

EUOMPHALUS ROTUNDATUS. Sow. SP.

Helicites Dionysii. Schlot—Euomphalus Dionysii. Gold. and Bronn.—Cirrus rotundatus. Sow. Min. Con.—
Cirrus rotundatus. Phil. Geol. York.

Sp. Ch.—Obtusely conical; volutions five or six, rounded, tip obtuse; height of the spire rather more than
two-thirds the diameter of last whorl; surface with faint, direct lines of growth.

This species is distinguished from the E. acutus by the volutions being uniformly convex, without the
flattened space on the upper part of each whorl, which is found in that species; the volutions are about five in
number. Diameter one inch six lines, height of the spire one inch.

EvUoMPHALUS SERPENS. Phil.
Euomphalus serpens. Phil. Pal. Fos.
Sp. Ch.—Discoid, spire convex, of four rounded, smooth whorls; umbilicus very wide, extending to the
tip of the spire.

The Ivish specimens are referrible to the smaller variety of this species found in N. Devon, and figured by
Professor Phillips in Pl. XXXVI. fig. 172, c. d.e. Diameter six lines, height of spire two and a half lines.

38 SYNOPSIS OF THE CHARACTERS OF THE

EVUOMPHALUS TABULATUS. Phil. sp.
Cirrus tabulatus. Pz. Geol. York.

Sp. Ch.—Obtusely conical, depressed; summit of the spire flattened; whorls with a nearly rectangular
keel in the middle, separating the upper half, which is flat or concave, from the lower, which is flattened, and
slightly oblique; mouth wider than long.

This species is remarkable for the square form of its whorls, which are plain or tabulate above, rounded
beneath, and widely umbilicate; they are usually about five in number; the upper portion of the spire seems as
if truncated. Diameter two inches, height ten lines, thickness of last whorl five lines.

PuatyscuismA. M‘Coy’.

Gen. Ch._—Obtusely conical, ventricose ; shell very thin; spire short, obtuse, of few whorls; aperture large,
lunate, rounded anteally, narrow retrally, with a very wide, shallow sinus in the outer lip, not forming a defined
band; surface smooth, or only marked by hnes of growth; umbilicus small, rounded.

This very distinct group of Pleurotomarie differs from all the Oolitic, and the other Paleozoic forms, in seve-
ral important characters, of which, the want of a definite mesial band is one of the most striking: they are also
recognized by their obtuse form; smooth surface, without keels of any kind; the great width and shallowness
of the sinus, as indicated by the lines of growth; and the thinness of their shells. They resemble the recent
Janthine strongly, but differ from them in having the mouth rounded anteally instead of being angulated, and
not having the pillar lengthened, as in that genus. The species appear confined to the carboniferous limestone.

PLATYSCHISMA CIRROIDES. M‘Coy. (Pl. VI fig. 2).

Sp. Ch.—Shell discoid, depressed, umbilicate; base flattened, or slightly concave; whorls five, very gra-
dually increasing, the last turn being but little larger than that which precedes it; slightly convex; body whorl
obtusely carinated on its lower edge, spire very obtuse.

A very fine species, resembling the P. helicoides in some particulars; it is, however, a much rarer shell,
and easily to be distinguished by the characters above mentioned. Diameter two inches three lines; height of
spire one inch three lines.

PLATYSCHISMA HELICOIDES. Sow. SP.

Ampullaria helicoides. Sow.—Pleurotomaria helicoides. Phil.

Sp. Ch.—Ovate, depressed; spire obtusely pomted, of four slightly convex whorls; base tumid; aperture
lunate, with an obtuse sinus in the middle of the outer lip, which is followed by the lines of growth; umbilicus
small, deep, rounded, spirally striated within.

This fine species is not uncommon; the shell is excessively thin; and from the wide, shallow, rounded
sinus, it seems more nearly allied to Janthina than either Ampullaria or Pleurotomaria.

Pratyscuisma JAMESH. DM‘Coy. (PI. V. fig. 20).

Sp. Ch.—Depressed, conical; spire obtusely pointed, of four or five flat, imbricating whorls; slightly tumid
at the sutures; base flattened, rounded at the circumference ; umbilicus small, surface marked with sharp, oblique
strie, having a broad, rounded, backward wave on the rounded circumference of the last whorl, and a little
above the suture on the turns of the spire.

This is one of those ambiguous little shells, most allied to T’rochus, and having much of the general cha-

* TlAatd;, wide; and cyscuen, a slit.

CARBONIFEROUS FOSSILS OF IRELAND. 39

racter of Pleurotomaria, but without the band, or the deep slit in the lip of that genus; the lines of growth
indicate a shallow, rounded sinus in the right lip, as in Janthina, but the great thickness of the shell in the
present species removes it very far from such delicate shells, and, together with the form, might approximate it
to Rotella ; but instead of the thick pad of enamel at the base of shells of that genus, the fossil is umbilicate.
Diameter six lines; height of spire three lines and a half.

PLatyscuisMa zoniTes. M‘Coy. (PI. V. fig. 17).

Sp. Ch.—Discoid; spire very depressed, obtuse, of five slightly convex whorls; circumference rounded;
base flattened ; umbilicus deep, rounded; surface nearly smooth, marked by obsolete lines of growth, having a
wide, backward bend in the middle of the whorls.

This little shell so closely resembles a recent Zonites, as to have suggested the specific name; it is more
depressed than any other species of Platyschisma, although the number of whorls is greater than is usual in
that genus. Diameter seven lines and a half; height of spire three lines.

Prevrotomaria. De Fran.

Gen. Ch.—Trochiform, generally imperforate; whorls frequently carinated ; a deep linear sinus in the
middle of the right lip.

PLEUROTOMARIA ALTAVITTATA. M‘Coy. (PI. V. fig. 11).

Sp. Ch.—Obtusely conical ; spire of three or four volutions; whorls plane above, rounded below ; band pro-
minent, flattened, situated above the centre of the volutions; surface smooth.

This much resembles the P. abdita, Phil., in shape, but is distinguished by the upper portion of the whorls
being tabulated, and the band, instead of being subsutural, as in that shell, is placed unusually high on the vo-
lutions ; the surface is quite smooth. Length six and a half lines, width eight lines.

PLEUROTOMARIA CANALICULATA. M ‘Coy. (PI. VI. fig. 3, a, 5).

Sp. Ch.—Shell conical, turreted, umbilicate ; upper third of the whorls flattened or concave at top; adeep,
smooth channel runs along the angle which separates the upper flat portion from the descending portion of the
whorls; spire acute, of five or six turns; mouth nearly round; all the whorls regularly and sharply striated spi-
rally. Height one inch two lines, width one inch three lines.

This beautiful shell is very distinctly marked by the suleus which runs along the upper edge of the whorls.
Height of spire one inch two lines, width at base one inch four lines.

PLEUROTOMARIA CARINATA. Phil.

Helix carinata. Sow. Min. Con.—Pleurotomaria carinata. Phil. Geol. York.

Sp. Ch.—Obtusely conical, volutions gently convex; band broad, simple, smooth ; oblique striz of the sur-
face very fine. Diameter one inch seven lines, height of the spire one inch one line.

PLEUROTOMARIA CLATHRATA. M‘Coy. (Pl. V. fig. 12).

Sp. Ch.—Obliquely ovate ; spire acute, of four very convex whorls; mouth circular; umbilicus very mi-
nute ; surface reticulated with sharp, prominent, transverse and concentric spiral ridges ; keel small, sharp, with
a broad, smooth groove on each side of it.

This beautiful little shell is distinguished from the others of its genus by the great convexity of the whorls
of the spire, circular mouth, which, with the small umbilicus, regularly latticed surface, and smooth space above
and below the keel, renders the present one of the most distinctly marked and elegant of the genus. Length
two and a half lines, diameter of last whorl two lines.

40 SYNOPSIS OF THE CHARACTERS OF THE

PLEUROTOMARIA CONCENTRICA. Phil.
Pleurotomariaconcentrica. Phil. Geol. York.

Sp. Ch.—Conical; whorls quadrate, plain above ; surface spirally sulcated ; basal sulci largest. No um-
bilicus.

There are about five turns in the spire; the quadrate form of the whorls, and spirally suleated surface, dis-
tinguish this from all the species except P. canaliculata, M‘Coy, from which it is distinguished by having a
distinct angle separating the flat upper part of each whorl from the lower, instead of a concave smooth groove,
as in that species. Diameter eleven lines, height of spire ten lines.

PLEUROTOMARIA CoNIcA. Phil.
Pleurotomaria conica. Phil. Geol. York.
Sp. Ch.—Acutely conical; height of spire nearly equal to the diameter of the base, umbilicate, band
formed of two or three keels, surface with sharp, oblique striae.
This shell has the spire higher, in proportion to its width, than most of the other species ; there are usually
three keels on the band, but sometimes there are only two; the oblique striz of the surface are beautifully
sharp and distinct. Diameter one inch four lines, height of the spire one inch three lines.

PLEUROTOMARIA DECUSSATA. MM‘Coy. (Pl. V. fig. 13).

Sp. Ch.—Conical, acute, spire of about five or six whorls; volutions flattened ; band broad, flat, defined,
placed low down on the basal whorl, and close to the suture on those of the spire; surface decussated by rough,
spiral, and oblique striae; umbilicus very small.

This species has the size and form of the P. conica, Phil., but has only one simple, broad, flattened keel,
instead of the two or three narrow ones of that species; besides which the surface of the present shell is marked
by strong spiral as well as oblique striz. Length one inch two lines, diameter of basal whorl one inch two

lines.

PLEUROTOMARIA LENTICULA. M ‘Coy. (PI. VII. fig. 5).

Sp. Ch.—Discoid, very much depressed, smooth; spire of five or six slightly convex whorls, nearly flat,
tip mammillary, base flattened; umbilicus very small, rounded; a narrow, sharp keel surrounding the last whorl;
surface perfectly smooth.

This species is remarkable for its very depressed form, the height of the spire being little more than a third
of the diameter; the whorls are all very smooth, and but little convex; the keel is only visible on the last
whorl; it is very narrow and sharp. Diameter one inch nine lines, height of spire nine lines, thickness of last

whorl six lines.

PLeuRoTOMARIA FILOSA. M‘Coy. (PI. V. fig. 14).
Sp. Ch.—Whorls very convex both above and below the keel, which is very large, prominent, rounded ;
surface with close, spiral, thread-like striz both above and below the keel.
This species is distinguished by its numerous fine, spiral, strie and large keel; there are about twenty
spiral strie between the keel and the suture above, alternately larger and smaller. Diameter of basal whorl
fourteen lines.

Prevroromaria Grirrirau. M‘Coy. (PI. VI. fig. 1).

Sp. Ch.—Acutely conical; whorls flat, base convex; a single, very prominent, square keel, in the middle
of the body whorl, but continued along the base of the spiral whorls, close to the suture ; umbilicus large, open,

conical.

CARBONIFEROUS FOSSILS OF IRELAND. 41

This magnificent fossil is rarely of a less size than that figured in the plate, and frequently reaches six
inches in diameter; the surface is almost perfectly smooth; the keel, which is very large and square, is much
nearer to the base than the centre of each turn; and the portion of each whorl below the keel is so convex, as
to give a channeled appearance to the sutures; the spire consists of six whorls, the keel extending to all of
them; the upper whorls appear rounded, as in the plate, only when the outer shell is absent, as was the case
with the specimen figured; umbilicus deep, conical, smooth. Length three inches, width four inches three
lines.

PreurotoMariA Hatnesu. MM‘Coy. (PI. IIL fig. 8).

Sp. Ch.—Conical, depressed; spire small, of three rounded volutions, having the band part above and
part below the suture, basal whorl lenticular, depressed above and below, rounded at the circumference, where
there is a narrow, prominent, square band; surface above marked with strong, equal sulci, slightly curved
where they set off from the spire, and extending obliquely backwards to meet the band at a very acute angle;
surface below the band smooth, or faintly striated across.

This beautiful species is dedicated to Dr. Haines, of Cork, who obligingly lent the specimen fioured.
Length five lines, width eight lines.

PLEUROTOMARIA HELICINOIDES. M‘Coy. (Pl. VIL fig. 6).

Sp. Ch.—Obtusely conical, lenticular, smooth; last whorl carinate; whorls convex beneath; concave
towards the outer edge, convex towards the suture above; umbilicus small, rounded.

This shell closely resembles the Huomphalus Qualterianus, but is known from it by the very small size
of the umbilicus, which, in the latter species, is so large as to expose the whorls. Diameter four lines; height
of spire two lines.

PLEUROTOMARIA La&vis. M‘Coy. (Pl. V. fig. 15).

Sp. Ch.—Very depressed, discoid; whorls narrow, obtusely rounded at the circumference; spire ob-
tuse, of three small whorls; mesial band narrow, flat, subsutural; surface smooth; umbilicus large, rounded.

This shell has its band concealed on the spiral whorls by the sutures, as in the P. abdita, Phil., from
which it differs in being umbilicate, and much more depressed. Diameter three lines; height of spire one line
and a half.

PLEUROTOMARIA MULTICARINATA. JM/‘Coy. (PI. V. fig. 16).

Sp. Ch.—Acutely conical; height and width about equal; body whorl small; spire of five or six rounded
or subquadrangular whorls; each whorl with three or four large prominent keels on the middle, above which
are four smaller ones, and beneath which, on the flattened base of the body whorl, are numerous small, spiral
keels, or sulci, all crossed by very fine, transverse striz ; umbilicus moderate.

This species in size and shape exactly resembles the P. conica, Phil., but is easily distinguished by its
greater number of keels; the body whorl is very little larger than that which precedes it; the mouth is round, or
slightly angulated, base rather flattened. Diameter one inch three lines; height one inch four lines.

PLEUROTOMARIA TORNATILIS. Phil. Geol. York.

A few very imperfect fragments, probably of this species, but unfit for description, have occurred.

Mourcutsonia. D’ Archiae and De Verneuil.

Gen. Ch.—Elongate, turreted; spire very long, of numerous whorls; keeled; generally striated obliquely ;
umbilicus very small, or none; a deep, narrow slit in middle of right lip; mouth nearly round; base short.

L

42 SYNOPSIS OF THE CHARACTERS OF THE

MuRrcHISONIA ELONGATA. Portk.
Murchisonia elongata. Portk. Geol. Rep.
Sp. Ch.—Very elongate; spire acute, of eleven angular, gradually increasing whorls; two keels bounding
the band on the angle, with two keels above, and two below, at equal distances.
This shell is intermediate in character between the M. angulata, Phil., and M. quadricarinata, Moy,
but perfectly distinct from both. Length nine lines, diameter of last whorl four lines.

Morcuisonia Larcomit. M‘Coy. (Pl. V. fig. 8).

Sp.Ch.—Spire of ten rounded volutions, each having slightly above the centre a flat mesial band, bounded
by two rounded keels, above which are two smaller keels, and below which are two similar keels, on all but
the basal whorl, which has three.

This pretty species is one of the most elongate of its genus; with the exception of the keels, the surface is
smooth. Length one inch, diameter of basal whorl five lines.

MURCHISONIA QUADRICARINATA. M‘Coy. (PL V. fig. 9).

Sp. Ch.—Elongate, conic; whorls numerous, gradually diminishing in size, angular, the principal angle
or keel being rather below the centre of each whorl; there are two smaller keels below the principal keel, and
one above it, on each whorl; sutures prominent; surface nearly smooth, with slight traces of oblique striz.

This species is alhed to the M. angulata, Phil., but the number of its keels, and slender form, distinguish
it from all of the genus. Length four and a half lines, diameter of last whorl one and a half lines.

Morcuisonia sutcatTa. M‘Coy. (PI. V. fig. 10).

Sp. Ch.—Acutely conical; spire of four gradually increasing, very convex whorls; the whorls of the spire
have four, and the basal whorl five broad, rounded, smooth, spiral, nearly equal grooves, separated by sharp
ridges; umbilicus very small.

This species is remarkable for the great convexity of the whorls, and their very gradual increase, the basal
turn being very little larger than the one preceding it ; two of the spiral ridges on the most prominent part
of each whorl seem to include the band between them. Length three and a half lines; diameter of last whorl
three lines; thickness of last turn one and a half lines.

Evencuus. Hum.

Gen. Ch.—Trochiform, spire lengthened; body whorl small, smooth; imperforate ; base of the pillar with
a prominent angle or tooth.

ELencuus antiquus. M‘Coy. (Pl. V. fig. 18).

Sp. Ch.—Ovate, smooth, spire pointed, of four slightly convex whorls; mouth half the length of the shell;
pular slightly thickened, obsoletely notched at the base; outer lip thin, straight; body whorl inflated ; base very
short.

This interesting shell may be distinguished from all the species of Macrocheilus, by the minute notch at
the base, and the short, slightly thickened, and twisted pillar. The general form is buccinoid or gibbous ovate ;
the surface is smooth, with very fine, direct, transverse striz. Length seven lines, width four lines.

ELENCHUS suBuLaTUS. M‘Coy. (PI. V. fig. 19).
Sp. Ch.—Elongate, subulate, spire of about six or seven flat, smooth whorls ; mouth ovate, rounded ante-
ally, narrow retrally ; a small strong tooth on the pillar lip; right lip simple.
This species belongs apparently to that splendid little group of New Zealand shells, long ago distinguished

CARBONIFEROUS FOSSILS OF IRELAND. 43

by Humphreys under the above generic title, and distinguished from the true Monodonte, principally by their
more elongate form, brilliant colouring, and the want of an umbilicus. The surface is perfectly smooth. Length
about six lines; length of mouth two lines; diameter of last whorl two and a half lines.

——_@—_—_

SCUTIBRANCHIA AND CYCLOBRANCHIA.

Those are remarkably well defined, not only from a consideration of their anatomy, but also in their tes-
taceous covering; their shells are all simply cup-shaped, never spiral, or very slightly so in a few aber-
rant forms, in which they differ from the Pectinibranchiate Gasteropoda, or ordinary spiral univalves. The
genera Acroculia and Patella, are found in the carboniferous limestone ; the first is scarcely distinguishable from
the recent Capulus, or the Tertiary genus Brocchia, while the latter is a well-known recent genus; although, I
must confess, that it appears to me that the shells we now call Patella in those rocks, do not really belong to the
present tribe, but are more nearly related to Umbrella of Lamarck ; it would require, however, more perfect
specimens than I have seen to settle the question, meanwhile I cannot do better than leave them in their pre-
sent position.

TROCHELLA. Sw.
Infundibulum. Mont.

Gen. Ch.—Conical, patelliform; apex central; spire internal, of two or three whorls; umbilicus very
small, or none.

TROCHELLA Prisca. M‘Coy. (Pl. VIL fig. 1).

Sp. Ch.—Conical, smooth; height rather greater than half the diameter; spire of four flat whorls; sutures
only indicated, on the outside, by an obscure depression; apex mammillary; mouth transversely elliptical; um-
bilicus smooth, roundish; circumference acute.

This fossil, although rather common, appears to have passed hitherto unnoticed, or, as I have frequently
known it, mistaken for a cast of the umbilicus of a Nautilus biangulatus, or some such shell. The discovery
of several fine specimens, shewing the under side, with the mouth and umbilicus, first enabled me to point out
its true nature, and to characterize it as a distinct species. When the outer shell is removed, the internal spire
can be distinctly seen; but when perfect, it is only indicated by the very slight convexity of the whorls, the
suture being completely covered by the external shell. Diameter one inch seven lines, height of spire eleven
lines.

FissuRELLA. Brug.
Gen. Ch.—Patelliform, apex perforated.

FissURELLA ELONGATA. M‘Coy. (PI. V. fig. 27).

Sp. Ch.—Length about twice the width, conical; sides parallel; extremities rounded; apex one-fourth
the length of the shell, from the anterior end; surface decussated by equal, radiating, and concentric ridges.

Although the perforation in the apex of this remarkable fossil is obscured by a breaking of the shell,
I have no hesitation in placing it in the present genus. It is very much elongated and compressed ; the extremi-
ties are rounded, the anterior being slightly the broadest; the anterior end is only one-fourth the length of the
shell, very convex; the posterior end is slightly depressed, the sides rather concave ; the surface is marked with
regular, rounded, radiating ribs, which are decussated by concentric sulci, placed at equal distances with the
radiating ones, so as to give a regularly chequered appearance to the surface. Length nine lines, width four
lines.

44 SYNOPSIS OF THE CHARACTERS OF THE

Dirmus. MM*‘Coy’.

Gen. Ch.—Patelliform; apex perforated by two oval foramina, symmetrically placed, one on the nght
side, the other on the left.

This most extraordinary genus is nearly related to the recent Fissurella of Lamarck; but instead of the
single dorsal, branchial opening of that genus, we have here two distinct, oval foramina, laterally placed with re-
spect to the apex, they are separated by a distinct, narrow, flattened septum. In some of the recent species of
Fissurella, the opening is contracted in the middle, so as to indicate an approach to the structure here noticed.
Only one species is as yet known to me.

Dririnus Buckianpi. M‘Coy. (Pl. V. fig. 28).

Sp. Ch.—Obovate, conical, depressed; apex prominent, obtuse, inclining forward one third the length
from the anterior margin; surface slightly irregular ; smooth, or with a few lines of growth near the margin.

This very curious little shell is obtusely trigonal in its outline, the front being obtusely rounded; the
posterior margin truncated ; lateral angles rounded; the posterior and lateral margins are about equal in length.
Length five lines; width five lines; height one line and a half; foramina three-fourths of a line in length, half
their length distant from each other.

Acrocutta. Phil®
Gen. Ch.—Shell obliquely spiral; spire dextral; mouth large; no columella; a deep, wide notch in the
right lip.
Acrocunia aNcusTaTa. Phil. sp.
Pileopsis angustus. Phil. Geol. York.

Sp. Ch.—Apex spirally involute, narrow ; mouth expanded; delicately striated across.

The transverse striw are exceedingly fine, the surface appearing smooth to the naked eye; the spire is
more perfectly formed than in any of the other species, and the mouth is dilated, the whole form approaching to
that of the Natica ampliata, Phil., which Goldfuss places in the present genus. Length nine lines, width of
the mouth six lines.

AcRocuLia CANALICULATA. M*Coy. (PI. IIL fig. 13).

Sp. Ch.—Subconical, compressed ; apex oblique, incurved; aperture deeply sinuated, trilobate ; from each
of the projecting lobes a deep channel extends to the beak, one passing up the back, and one in the middle of
each side; there are a few irregular minor sulci parallel to the principal channels.

The trilobate aperture approximates this species to the A. triloba, Phil., but the apex is more oblique, and
the deeply channeled surface distinguish it equally from that, and from the other described species ; the nght
lateral furrow is deeper than the left. Length nine lines, width five lines.

Acrocutia carInaTa. M*Coy.
Pileopsis cassideus. D’A rehiac and De Verneuil.

Sp. Ch.—Obliquely conical ; apex free, incurved ; very much compressed ; back sharply keeled ; surface
smooth.

* Etym. 9%, double, and ws, the nostrils, in allusion to its double breathing holes.

> Although the name Platyceras of Conrad has the priority over the term Acroculia, yet the former seems so singu-
larly inappropriate, that I have retained Professor Phillips’s name, which has been already extensively adopted by Euro-
pean writers.

CARBONIFEROUS FOSSILS OF IRELAND. 45

In July, 1841, I published a description of this species ina catalogue which I wrote of my friend, the late
Major Sirr’s fossils, who had collected the specimens from the Kildare limestone. The following year Viscount
D’Archiac and M. de Verneuil published a description of a fossil from the greywacke of Kemmenau, which

seems identical, although much less compressed.

AcrocuLia stamorpatis. Phil.
Acroculia sigmoidalis. Phil. Pal. Fos.

A small fragment of this species, unfit for description, has occurred.

ACROCULIA TRILOBA. Phil. sp.
Pileopsis triloba. Phil. Geol. York.
Sp. Ch.—Compressed, conical, arched ; apex free, deflected, obtusely pointed ; aperture distinctly trilobate,

surface marked with lines of growth parallel to the margin, otherwise smooth.
This remarkable species is known from the 4. vetusta by its more compressed form and free apex.

ACROCULIA TUBIFER. Sow. SP.
Pileopsis tubifer. Sow. Min. Con.—Pileopsis tubifer. Phil. Geol. York.

Sp. Ch.—Conical, acute, apex obtuse, not incurved ; three obscure, longitudinal undulations in the front ;
each bearing a row of long tubular spines.

This species is much more lengthened and narrow than any of the others; the apex is arched, but not dis-
tinctly incurve at any stage of growth ; the three rows of tubular spines are very remarkable. Length eleven
lines, diameter of the mouth six lines.

Acrocuiia vetusta. Phil.
Pileopsis vetusta. Sow. Min. Con.—Pileopsis vetusta. Phil. Geol. York.—Acroculia vetusta. Phil. Pal. Fos.

Sp. Ch.—Shell obliquely conical, gibbous; spire enrolled; mouth nearly circular im young, but lengthened
in old individuals.

Much doubt has arisen as to what shell was intended by Sowerby for his Pileopsis vetusta, every subse-
quent writer quoting his figure with a mark of doubt, the shells which most usually occur not presenting the
compressed form, lengthened aperture, or longitudinally undulated surface of Mr. Sowerby’s larger figure, but
agreeing perfectly with his smaller one ; hence the question has arisen, whether Mr. Sowerby has confounded
two species of Pileopsis, and which of them has the best right to the specific name vétusta. It appears that
young specimens have the mouth almost circular ; the surface smooth or obscurely wrinkled transversely, and
the whole shell having a gibbose or inflated appearance; the beak delicate, acute, and incurved, in this state
agreeing perfectly with Sowerby’s 2 and 3 in the Mineral Conchology, Professor Phillips’s figures in the
Geology of Yorkshire, Palaeozoic Fossils, &c.; by age, however, the sides become compressed ; the back narrow,
flattened, and bounded on each side by an irregularly rounded ridge or undulation, the beak becomes blunt, the
mouth lengthened, and the lip undulating. Length of an old individual two inches four lines ; length of the

aperture one inch nine lines; width one inch three lines.

Parerta. Linn.

Gen. Ch.—Conical, depressed ; apex inclined to the anterior side; aperture oval ; muscular impression in-

terrupted at the head of the animal; surface radiatingly striated.
M

46 SYNOPSIS OF THE CHARACTERS OF THE

PATELLA MucRONATA. Phil.
Patella mucronata. Phil. Geol. York.
Sp. Ch.—Orbicular, depressed, smooth; vertex mucronate, central.
Professor Phillips mentions that the base is not plane in this species, but my specimens are too imperfect

to ascertain this fact; yet from the mucronate apex, and general form, I have no doubt that they are the same.
Diameter eleven lines, height five lines.

PATELLA scuTirorMis. Phil.
Patella scutiformis. Phil. Geol. York.
Sp. Ch.—Shell oval, depressed, smooth; apex acute, inflexed, nearly marginal.
I have, as yet, seen but very bad specimens of this species, which, nevertheless, seems distinct, by its re-

gular elliptical form, and nearly marginal apex. Professor Phillips mentions fine, radiating striz on his speci-
men, but they are not visible in the examples I have examined.

PATELLA sinuosa. Phil.
Patella sinuosa. Pil. Geol. York.

Sp. Ch.—Ovate; anterior end narrower, with a wave or sinus on each side; vertex prominent, one fourth
the length of the shell from the anterior end.

This fine species is chiefly remarkable for the simuosity on each side, at the anterior end. Length one
inch nine lines, width one inch.

SIPHONARIA. Sow.

Gen. Ch.—Patelliform; a siphon, or canal, from the apex to the margin, at one side of the head.
The lateral siphon of this genus, which distinguishes it from Patella, is not only visible internally,

leavig a scar, which interrupts the muscular impression; but is frequently visible externally, and shghtly
affects the margin.

Srpponaria Konincxi. M‘Coy. (Pl. Il. fig. 14).

Sp. Ch.—Longitudinally oval; width rather more than three-fourths the length, shghtly irregular, apex
prominent, obtuse, slightly nearer the anterior than the posterior end, and nearer to the left than the right
side; an obtusely rounded furrow extends from the beak obliquely to the left side of the anterior end; surface
smooth.

Most nearly allied to the Patella lateralis, Phil., which is possibly also of this genus; it differs, however,
from that species, in its more lengthened form, obtuse apex, and entirely wanting the posterior radiations. From
the Umbrella levigata, M‘Coy, it is distinguished by its large, lateral apex, greater convexity, and anterior,
obligue furrow. Length seven lines, width six lines and a half.

Umpretia. Lam.

Gen. Ch.—Suborbicular, patelliform, depressed; apex nearly central, margin acute; muscular impression
continuous.

UMBRELLA LaviGATA. M‘Coy. (PI. V. fig. 31).

Sp. Ch.—Ovate, margin sharp, slightly sinuous on each side at the anterior end, apex nearly central ; sur-
face smooth, with one or two very obscure concentric undulations.

From the sharpness of the edge and smoothness of the surface, I think there can be little doubt of this
shell being more nearly related to !/mbrella than to Patella. The only fossil this runs any risk of being con-

CARBONIFEROUS FOSSILS OF IRELAND. 47

founded with is the Patella sinuosa of Phillips, from which it is readily distinguished by its nearly central
apex. Length one inch five lines, width one inch two lines, height two lines.

Dentatium. Linn.

Gen. Ch.—Shell conical, tubular, slender, arched; open at both ends.

DrnTALium Inornatum. MM‘Coy. (Pl. V. fig. 30).

Sp. Ch.—Tube slightly arched, very gradually tapering, mouth circular; surface plain, smooth.

This is the first example I have seen of the genus Dentalium in the Ivish palxozoic rocks; it is not unlike
the recent D. entalis, and like it, is smooth, and entirely without the longitudinal ridges which ornament so
many of the species; but it is considerably smaller, seldom attaining, I should think, a greater length than one

inch; the imperfect specimens usually found are little more than half that, and have a diameter of about three-
fourths of a line.

DITHYRA.
TEREDO (?) anTIQuA. M*Coy. (Pl. VIIL fig. 1).

Sp. Ch.—Tube irregular, flexuous, nearly cylindrical, about three-fourths of a line in diameter; irregu-
larly wrinkled transversely ; anterior end flattened, and terminating in two short tubuli.

This curious shelly tube occurs occasionally in considerable abundance; the specimens are usually about
three-fourths of an inch in length, and from one-half to three-fourths of a line in diameter, twisted in every
direction. The tube terminates distinctly in two smaller tubuli, whence I have placed it as a T'eredo, although
with some doubt.

Genus Souenopsis. M‘Coy.

Gen. Ch.—Transversely elongate, equivalve, inequilateral, beaks prominent, close to the anterior end;
anterior end short, rounded, closed; posterior end elongate, truncated, slightly gaping.

I have instituted the present genus for the reception of a few fossils of the carboniferous series, hitherto
ranked by Goldfuss and others with the genus Solen ; from this genus they are distinguished by their prominent
beaks, which are never terminal, and their rounded and closed anterior end. From Solenocurtus they differ mm
being inequilateral; from Nweula and Solenella they differ in the want of lateral teeth, and in their gaping,
posterior end. The few species I know are all from the Paleozoic rocks, and scarcely differ except in size.

SoLenopsis minor. M*Coy. (Pl. VIII. fig 2).
Solen pelagicus. Porth. (Not of Gold.)

Sp. Ch.—Width three times the length; anterior end short, rounded; surface with irregular, concentric
strie.

This species differs from the Solen pelagicus, Gold., in its being less elongate transversely, having a
broader anterior end, and being entirely without the sinus, which extends from the beak to the ventral margin
im that species; from the Solen vetustus of the same author, which it more nearly resembles, it differs in not
being radiated, and in its strong, diagonal, posterior ridge. Length four lines, width eleven lines.

Sancuinouites. MM<Coy.
Gen. Ch.—Transversely oblong, convex, equivalve, very inequilateral ; dorsal and ventral margins paral-
lel, or nearly so; anterior side short, rounded; posterior side lengthened, obliquely truncated, gapimg; an
oblique ridge usually extends from the beak to the anal angle, but no flexure; ligament external.

48 SYNOPSIS OF THE CHARACTERS OF THE

This genus has been formed to include a number of fossil shells of the older rocks, hitherto classed with
Sanguinolaria. The latter shells have the dorsal and ventral margins curving towards each other posteriorly ;
forming a submucronate, beak-like termination, to the posterior end, while, on the contrary, the dorsal and ven-
tral margins of the present shells are nearly parallel, so that the posterior end is as wide, or wider than the
other parts of the shell; they are also much more gibbose, and have no posterior fold.

SANGUINOLITES ANGUSTATUS. Phil. sp.
° Sanguinolaria angustata. Phil. Geol. York.

Sp. Ch.—Nearly four times as wide as long; posterior end subtruncate, separated from the body of the
shell by a distinct diagonal ridge from the beak; anterior end short, rounded; surface with coarse, transverse
sulei; the posterior triangular space nearly smooth.

This shell is nearly flat, very much elongated transversely; the hinge-line and front margin are nearly pa-
rallel; length seven lines, width one inch eleven lines.

SANGUINOLITES ARCUATUS. Phil. sp.
Sanguinolites arcuatus. Phil. Geol. York.
Sp. Ch.—Transversely elongate, gibbous; posterior, dorsal margin convex; ventral margin nearly parallel
to the dorsal, concave; surface smooth, with irregular lines of growth.
This remarkable shell seems more closely allied to some of the terebrating Modiole or Lithodomi, than to
Sanguinolaria. I have not seen specimens perfect enough to give the proportional measurements.

SANGUINOLITES ConTorTUS. MM‘Coy. (Pl. XIX. fig. 3).

Sp. Ch.—Transversely oblong, twice and a half as wide as long; beaks very large, tumid; from whence to
the posterior part of the front margin, the shell is obliquely gibbous, but without a distinct ridge; middle of the
shell and posterior side flattened, so as to give rather a twisted appearance to the shell; anterior side narrow,
pointed, rounded, having a lengthened, ovate lunule beneath the beak ; posterior end obliquely truncated ; sur-
face smooth.

This species is wider than the Unio Ansticei, and most nearly resembles the common S. tumida, from which
it differs in having the posterior end broader, and instead of the sharp, straight, diagonal ridge of that species,
there is a very obtuse, rounded, undefined convexity, so curved as to give a twisted appearance to the whole shell ;
the posterior side is never flattened in that species; in that shell also there are three rounded ridges, from the
beak to the posterior end, which do not exist in the present shell, which is further distinguished by its more
pointed, lengthened, and compressed anterior side. Length of a small specimen eleven lines, width two inches
four lines. The specimen figured was presented by Mr. Newenham of Cork.

SANGUINOLITES CosTELLATUS. M‘Coy. (Pl. VIIL fig. 5).

Sp. Ch.—Transversely oblong, depressed ; anterior side short, rounded, marked towards the margin with
four or five short, flat, radiating ribs.

This rare species is distinguished from all others by the radiating ridges on the anterior side; the specimen,
although imperfect at the posterior end, is very much elongated transversely, probably three times as wide at
long. Length six lines.

SANGUINOLITES cuRTUS. MM*‘Coy. (Pl. XI. fig. 1).

Sp. Ch.—Transversely oval, convex; width rather less than twice the length; anterior and posterior ends
nearly equally rounded ; abdominal margin rounded; no posterior diagonal ridge; surface of the anterior end,
and body of the shell, strongly plicated transversely ; one-half of the ridges disappear on reaching the posterior

slope, every alternate one suddenly dilating, so as to form very obtuse, smooth ridges, as they pass over the pos-
terior area,

CARBONIFEROUS FOSSILS OF IRELAND. 49

This species resembles the §. rugosa, Phil., in the arrangement of the transverse ridges, but differs in being
much less wide in proportion to the length. Length eight lies, width one inch two lines.

SANGUINOLITES Discors. M‘Coy. (PI. VIII. fig. 4).

Sp. Ch.—Transversely oblong, convex, three times as wide as long; beaks prominent, small; anterior side
short, rounded ; front margin slightly convex; posterior end obliquely truncated, posterior slope separated from
the body of the shell by a strong ridge from the beak to the posterior inferior angle; body of the shell marked by
strong, transverse, equal ridges, which stop suddenly at the oblique posterior ridge, leaving the posterior slope
smooth.

This shell derives its most prominent character from the discordance which exists between the posterior
slope and the body of the shell, the former being perfectly smooth, while the whole of the latter is strongly
sulcated transversely ; it is rather more depressed than the allied species. Length four lines, width one inch.

SANGUINOLITES IrtprnorpeEs. M*Coy. (PI. XII. fig 1).

Sp. Ch.—Shell flat, nearly four times wider than long; anterior side short, angular at the hinge; anterior
side and body of the shell marked with fine, crowded wrinkles, which change into broad, obsolete undulations,
in passing over the obscurely marked, diagonal ridge which runs from the beak to the inferior posterior angle;
posterior end broader than the anterior, obliquely subtruncate ; hinge-line three-fourths the width of the shell.

This shell resembles an Jridina in form. There is a slight depression parallel to, and a little below the
hinge-line; the oblique, posterior ridge is much better marked in some specimens than in others; above it the
undulations of the surface are broad, and slightly convex, but, immediately below it, suddenly diminish in size
and inerease in number, and, becoming more prominent, continue so to the anterior end; the depth of the shell
gradually increases from the anterior to the posterior extremity. From the beak to the ventral margin, mea-
sured at right angles with the hinge-line, one inch three lines; from the anterior to the posterior end five inches.
This shell is distinguished from the S. undata, Portk., by that species having numerous, strong, prominent
ridges, continued without any sensible increase in number or diminution in size across the body of the shell, the
anterior side is also much narrower and rounded. The differences from the S. transversa, Portk., are pointed
out under that head.

SANGUINOLITES LIRATUS. Phil. sp.
Sanguinolaria lirata. Phil. Pal. Foss.

Only very imperfect specimens of this species have occurred. The form resembles that of 8. plicatus,
M‘Coy, but the surface is regularly marked with strong, nearly equal, elevated ridges, parallel with the margin.

Saneurinoiites pricatus. M‘Coy. (Pl. X. fig. 3, a, b).
Sanguinolaria plicata. Porth. Geol. Rep.

Sp. Ch.—Twice and a half as wide as long, convex; posterior end subtruncate; anterior end rounded;
surface with close, irregular, transverse sulci, parallel to the margin.

This species, when in shale, is usually depressed, and the transverse sulci assume the appearance of plaits,
or folds; when in limestone, however, it is more convex, and the transverse markings appear finer and more re-
gular; there is some indication ofa diagonal keel near the beak, but it becomes obsolete before reaching half-way
to the posterior end; there often appears, particularly in shale speciiens, a concave space from the beak to the
opposite part of the front margin. Length seven lines, width one inch four lines. The plate contaiming the figure
of this species, under the name Sanguinolaria plicata, was presented to the Geological Society of Dublin, some
years ago, at an evening meeting, at which Captain Portlock was present. As he has figured the same fossil,
under the same name, in his Geological Report, I am uncertain whether he intended to attribute the species to
himself or to me.

N

50 SYNOPSIS OF THE CHARACTERS OF THE

SANGUINOLITES RADIATUS. M* Coy. (PI. XIIL fig. 4).

Sp. Ch.—Transversely oblong, nearly three times as wide as long, evenly convex; dorsal and ventral
margins parallel, ends equal, rounded; surface radiated with about twelve unequal, broad, convex ribs, from
the beak to the ventral margin; anterior and posterior extremities smooth; no posterior oblique ridges.

Length four lines, width ten lines.

SANGUINOLITES suLcATUS. Phil. sp.
Sanguinolaria sulcata. Phil. Geol. York.

Sp. Ch.—Transversely oblong, twice and half as wide as long, convex; posterior end subtruncate,
rounded, gaping; anterior end small, rounded; surface with large wrinkles on the posterior slope, which divide
each into two or three sharp, narrow sulci, on the body and anterior end of the shell.

This species is almost always found with the two valves together; the large, posterior wrinkles dividing
each into a number of small ones, as they cross over the body of the shell, give a curious character to the sur-
face. Length one inch, width two inches five lines.

SANGUINOLITES TRANSVERSUS. Portk. sp.
Sanguinolaria transversa. Porth. Geol. Rep.

Sp. Ch.—Transversely elongate, lanceolate; width three and a half times the length; beaks very small,
close to the anterior end; anterior end short, rounded; ventral margin convex; posterior end narrow, obliquely
truncated; hinge-line nearly as long as the width of the shell; surface marked with small, faint lines and
waves of growth.

From the drawing given in Captain Portlock’s Report, this species has been thought to resemble the
S. vetusta, M‘Coy ; but when specimens are compared, the species seem quite distinct; the striz and concentric
waves of the former species are fine, and so faint as to be nearly obsolete, while in the latter they form large,
rounded, prominent ridges; and one unvarying character, observable even in a cast, would distingush them, in-
dependent of surface, namely, that in the S. transversa the posterior end is considerably narrower than the
length from the beak to the opposite ventral margin, while in the S. vetusta it is considerably broader.
Length one inch one line, width three inches nine lines.

SANGUINOLITES TRICOSTATUS. Portk. sp.
Sanguinolaria tricostata. Portk. Geol. Rep.

Sp. Ch.—Transversely oblong, nearly three times as wide as long; diagonally gibbous; beaks large, pro-
minent; anterior side very short, rounded; front margin slightly convex, with a shallow sinus opposite the
beak ; posterior side lengthened, obliquely rounded; a strong ridge extends from the beak to the posterior in-
ferior angle; between this keel and the hinge-line, are two other strong, rounded, radiating ridges, dividing
the posterior slope into three equal, concave spaces; surface marked with close, fine, transverse striz.

This handsome species, in general form, resembles the S. tumidus, but the posterior ridges are more dis-
tinct, and the regularly striated surface at once distinguishes it. Length nine lines, width two inches one line.

SANGUINOLITES TuMIDUS. Phil. sp.
Sanguinolaria tumida. Phil. Geol. York.

Sp. Ch.—Three times as wide as long, very gibbous; beaks large, tumid; a distinct keel runs from the
beak to the posterior angle, separating the posterior slope from the body of the shell; surface smooth; three
obscure, radiating ridges on the posterior side.

This large species has the beaks remarkably prominent; the surface is smooth, with the exception of a few
imbricating lines of growth. Length one inch ten lines, width three inches eight lines.

CARBONIFEROUS FOSSILS OF IRELAND. 51

SANGUINOLITES UNDATUS. Portk. sp.

Sanguinolaria undata. Porth. Geol. Rep.

Sp. Ch.—Transversely elongate, width about three and a half times the length; depressed; posterior end
obliquely truncated, broad; anterior end very narrow, rather lengthened, rounded; surface regularly marked
with strong, equal, subangular, concentric ridges, continuing strongly defined across the whole shell; interme-
diate spaces broad, concave, smooth.

This species differs from the Sanguinolites Iridinoides, M‘Coy, in the strong, prominent ridges being con-
tinued equally from the posterior end, across the entire body of the shell to the anterior end, with a very trifling
diminution in size, and without increasing perceptibly in number; the ridges are narrower, more equal, and
the intervening species broader and smoother, than in that shell; they are also bent more angularly at the
posterior end; the anterior end is much narrower in the present species.

Anatina. Lam.

Gen. Ch.—Shell very thin, inequivalve, inequilateral, transverse; hinge, with a spoon-shaped process,
containing the cartilage, and a small, lengthened, testaceous appendage.

ANATINA ATTENUATA. M‘Coy. (PI. VIL fig. 6).

Sp. Ch.—Transversely ovate, attenuated posteriorly; gibbous, smooth; beaks prominent, anterior end
rounded; front margin very convex.

This curious fossil and the next are referrible, with tolerable certainty, to the genus Anatina, not only from
the excessive thinness of the shell and external form, but from the characteristic testaceous appendage to the
hinge, which is very frequently preserved in both species.—(It has been unfortunately obliterated from the
Plate during the preparation of the stone for printing.) The form ofthe present species is clavate, being
rounded, and very gibbous anteriorly, attenuated, narrow, and compressed posteriorly, where it is also rounded,
but is slightly oblique; the beaks are very large, but somewhat flattened at the tip; the testaceous appendage
of the hinge is about two lines long, flat, very narrow, and dilated at the tip; muscular impressions are distinct,
the anterior being rounded, oval; the posterior one crescent-shaped, palleal impression sinuous. Length seven

lines, width ten lines.
ANATINA DELTOIDEA. M‘Coy. (PI. VIIL fig. 7).

Sp. Ch.—Subtrigonal, gibbous; anterior side large, rounded; front margin very convex; posterior side
compressed, broad, obliquely truncated, separated from the body of the shell by an obtuse ridge, extending from
the beak to the posterior-inferior angle; surface smooth.

This species is easily distinguished from the 4. attenuata, M‘Coy, by the shortness and breadth of the
posterior side, and also by its greater convexity; the shell is excessively thin; the appendage to the hinge is
about a line and a half in length, and one-fourth of a line in width, the sides are nearly parallel, truncated at

the tip; muscular impressions large, crescent-shaped ; palleal impression sinuous. Length seven and a half lines,
width ten lines.

Panpora CLAVATA. M‘Coy. (Pl. XI. fig. 2).

Sp. Ch.—Transversely elongate, clavate, width twice and one-third the length; beaks small, close to the
anterior end; anterior end short, rounded; posterior attenuated, shghtly recurved, truncated at the extremity ;
one valve very convex, the other flat; surface of both valves strongly striated transversely.

This interesting little shell has a slightly marked posterior ridge. Length three lines, width seven lines.

52 SYNOPSIS OF THE CHARACTERS OF THE

Epmonp1A (?) compressa. M‘Coy. (Pl. XII fig. 10).

Sp. Ch.—Transversely oval, evenly convex, no posterior ridge or diagonal gibbosity ; beaks small, close to
the anterior end; anterior end short, rounded; ventral margin convex, posterior end obtusely rounded ; surface
marked with fine, irregular, concentric wrinkles of crowth.

I have placed this handsome fossil provisionally in the genus Edmondia of Koninck, it resembles the Lw-
traria primeva, Portk., but is smoother, and wants the large, prominent beaks, diagonal gibbosity, andtwisted
appearance of the posterior side, found both in that species, and in the U. Urii, to which it is allied. Length
one inch, three lines, width two inches one line.

Lurraria ELoncatTa. M‘Coy. (Pl. VII fig. 3).

Sp. Ch.—Twice as wide as long, convex; beaks large, prominent, slightly flattened; anterior end short,
rounded ; posterior side very much elongated transversely, recurved, truncated at the extremity ; dorsal and ven-
tral margins nearly parallel; surface marked transversely with wrinkles parallel with the front margin, and
truncated posterior end.

This curious little species is very rare, only one specimen having as yet occurred. Length four lines and
a half, width ten lines.

Lutraria prisca. M‘Coy. (Pl. XII. fig. 4).

Sp. Ch.—Shell transversely elongate, oval, convex, smooth, or slightly striated concentrically ; posterior
end narrowed, rounded, subtruncate, ventral margin very convex; beaks prominent, large.

This shell is much less transverse than the LZ. primeva, Portk., that species bemg much wider in propor-
tion to the length, it also has*the ventral margin nearly straight, while it is nearly semicircular in the present
species. Length two inches five lines, width three inches nine lines.

Macrra ncrassata. M‘Coy. (Pl. XIX. fig. 8).

Sp. Ch.—Obtusely trigonal, width about one-sixth greater than the length; convex; beaks central, large ;
anterior and posterior ends equal, obtusely rounded; surface marked with several strong, distant, irregular,
thickened marks of growth; between which, especially towards the margin, are finer, transverse lines of growth.

This fine species resembles the recent M. solida in most of its characters, but 1s considerably larger. Length
two inches seven lines, width two inches eleven lines.

Mactra ovata. M'‘Coy. (Pl. XI. fig. 3).

Sp. Ch.—Transversely ovate, convex, smooth; beaks small, subcentral, nearest the anterior side; anterior
side rounded; posterior side obtusely pointed ; posterior area compressed.

When examined with a lens, there appear some faint, transverse striz. Length seven lines, width nine
lines.

Kerrra crecaria. M‘Coy. (Pl. XI. fig. 5).

Sp. Ch.—Transversely oval, length three-fourths the width, compressed ; beaks close to the anterior end;
very slightly convex; anterior and posterior ends equal, very obtusely rounded; surface smooth, with a few de-
licate wrinkles of growth near the margin.

In this interesting little shell the transverse wrinkles are inconstant and irregular, having precisely the
membranous character of those of Cyclas or Pisidium ; it seems, however, most allied to Kellia suborbicularis.
Length two lines, width nearly three lines.

CARBONIFEROUS FOSSILS OF IRELAND. 53

Psammosia pEcussaTa. M‘Coy. (Pl. X. fig. 2).

Sp. Ch.—Transversely rhomboidal, gibbous ; beak near the anterior end, which is short, rounded ; posterior
end obliquely truncated; surface with irregular, transverse sulci, decussated by close, fine, longitudinal striz.

There is an obtuse ridge separating the posterior side from the body of the shell, the transverse sulci are at
unequal distances, but the longitudinal striae are very regular, close, and rounded. Length eight lines, width
one inch two lines.

Lucina antigua. M‘Coy. (Pl. VIII. fig. 9).

Sp. Ch,—Orbicular, slightly convex; beaks pomted; lunule very small; surface marked with delicate,
sharp, concentric striz.

This handsome species is almost perfectly orbicular, the posterior margin being very slightly angulated ;
the lunule is small, but deep, ovate; concentric stria very fine; it is less convex than most species of the genus.
Length one inch three lines, width one meh four lines.

Uncutina antiqua. M‘Coy. (Pl. VII fig. 8).

Sp. Ch.—Longitudinally ovate; length one-sixth greater than the width, evenly convex; beaks small,
rounded from the posterior side; a depression in front of the beaks, where the anterior margin is slightly
flattened ; surface nearly smooth, with an irregular, concentric plication, strongest on the posterior side.

This singular shell appears so closely allied to the recent Ungulina transversa, that I have included it in
the same genus. Length one inch three lines, width one inch one line.

AMPHIDESMA suBTRUNCATA. M/‘Coy. (Pl. X. fig. 10).

Sp. Ch.—Subquadrate, rhomboidal, depressed, smooth; anterior side rounded ; posterior side subtrun-
eate, very obscurely flexuous; beaks small, pointed, subcentral; surface smooth.

This species has a very thin, smooth shell; the beaks are small but prominent; the posterior end is
slightly beaked and flexuous. Length one inch one line, width one inch three lines.

Corpis CANCELLATA. M‘Coy. (Pl. VIIL fig. 14).

Sp. Ch.—Transversely obovate, one-third wider than long, compressed ; shell thick, regularly cancellated
by equal, radiating, and transverse, thin, prominent ridges; beaks large, prominent; anterior side small; poste-
rior side somewhat attenuated, subtruncate, rounded.

The thick, regularly cancellated shell induces me to include this fossil in the genus Corbis, for the pre-
sent, although it is much more compressed, and inequilateral, than the other species. The general form is ob-
ovate, the posterior portion of the shell being perceptibly narrower than the anterior; the beaks project
considerably, but are compressed; they are about two-thirds the length from the posterior extremity. Length
one inch three lines, width one inch nine lines.

Venus cenTraLis. M‘Coy. (Pl. XI. fig. 6),

Sp. Ch.—Transversely oval, convex ; anterior and posterior sides equal or nearly so, rounded ; beaks small,
central; surface marked transversely with close, unequal, rounded ridges.

This is distinguished from the /. elliptica, Phil., by the almost perfectly central position of the beaks, the
transverse wrinkles are also finer and more numerous in the present shell; they are sharpest at the anterior side.
Length two lines, width three lines. The beaks are rather more central than in the figure.

O

54 SYNOPSIS OF THE CHARACTERS OF THE

VENUS TENUISTRIATA. M‘Coy. (PI. VIII. fig. 10).

Sp. Ch.—Suborbicular, slightly transverse, convex ; anterior side and front margin rounded ; posterior end
subtruncate, rounded, beaks prominent; surface roughened by very close, fine, concentric striz; a deep sinus in
the palleal impression.

This rare species is but slightly convex; the beaks are large, the anterior side short and rounded, the dor-
sal margin is slightly convex, the transverse strie are very fine and closely placed ; the sinus in the impression of
the mantle is very deep, with parallel sides, rounded at the end. Length one inch three and a half lines, width
one inch seven lines.

PULLASTRA ANTIQUA. Sow.

Pullastra antiqua. Sow. Geol. Trans.

The specimens which have occurred of this species are too imperfect for description.

PULLASTRA BISTRIATA. Porth.
Pullastra bistriata. Porth. Geol. Rep.

Sp. Ch.—Transversely elliptical, oblique, slightly convex, flattened in the middle ; beaks small, close to
the anterior end ; anterior side very short, rounded, posterior end obliquely subtruncate ; hinge-line straight,
three-fourths the length of the shell; shell girt with about ten concentric step-like ridges, rounded on their ven-
tral edge, flattened above, each beautifully sculptured with close, rounded, prominent zig-zag lines.

This beautiful shell is exceedingly common in the carb. slate of several districts in Ireland; it is distin-

guished by the peculiar sculpturing of the surface from any other fossil. Length three lines, width seven
lines.

PULLASTRA CRaAssisTRIA. M‘Coy. (Pl. XI. fig. 7).

Sp. Ch.—Transversely oval, very gibbous; dorsal and ventral margins equally convex; anterior and pos-
terior ends nearly equal, rounded, subtruncate ; surface closely marked with unequal, obtuse, concentric
ridges.

This little species is remarkable for its equal convexity, thick, regular, transverse strie. Length five lines,
width nine lines.

PuLLasTRA ELEGANS. M‘Coy. (PI. VIII fig. 16).

Sp.Ch_—Transversely oblong, gibbous; length two-thirds the width ; front margin and hinge-line straight
and nearly parallel ; anterior side very short, rounded; posterior end truncated ; posterior slope separated from
the body of the shell by a large, obtuse, diagonal, rounded ridge from the beak ; surface marked with fine, regu-
lar, transverse striz, having between them broad, flat, regular, smooth spaces, parallel with the margin.

There is a peculiar squareness of contour in this shell, resulting from the abrupt truncation of the posterior
end, and the straight and nearly parallel dorsal and ventral margins; although very gibbous, the front is flat-
tened, as is also the posterior slope, the separating ridge being obtusely rounded, the beaks large and tumid;
the form is strongly allied to some of the tertiary species of Petricola. Length ten lines, width one inch
one line.

PULLASTRA ELLIPTICA. Phil. sp.
Venus elliptica. Phil. Geol. York.

Sp. Ch.—Transversely elliptical, convex; surface with broad, concentric undulations.
Length six lines, width nine lines.

CARBONIFEROUS FOSSILS OF IRELAND. 55

Puntastra ovaris. M‘Coy. (Pl. VIL fig. 20).

Sp. Ch.—Transversely oblong, convex, twice as wide as long; ventral and dorsal margins parallel; beaks
small, close to the anterior end; anterior end very short, rounded; posterior end subtruncate; surface with
numerous, rather distant, sharp, concentric striz.

This fine species partakes of the general similarity of habit of all the other Pullastre; it is, however, easily
distinguishable from all the Palwozoic species by its great size and peculiar outline: the concentric striw are
sharp, fine, and placed rather distant from each other, so as to form numerous, regular, flat spaces between
them (these spaces are usually elevated in the recent species, but the delicate intermediate strie are usually
elevated in the fossil ones); the posterior end is slightly truncated; the beaks tumid, but not very prominent ;
anterior side very short. Length one inch two lines, width two inches four lines.

PULLASTRA PARALLELA. Phil. sp.
Venus parallela. Phil. Geol. York.

Sp. Ch.—Transversely ovate, flattened; bezks subcentral; dorsal and ventral margins nearly parallel;
anterior side narrow, rounded; posterior subtruncate; lunule large, deep; surface with delicate, sharp, concen-
tric striz.

This beautiful little shell appears to belong to the recent genus Pullastra, it is slightly quadrate in form,
the posterior end being subtruncate, the surface is beautifully striated. Length four lines, width six lines.

Astarte cipposa. M*Coy. (Pl. VIII. fig. 11).

Sp. Ch.—Orbicular, length five-sixths of the width, gibbous, with regular concentric ridges; posterior
side subtruncate, rounded; anterior side small, rounded; beak small, tumid.

This handsome shell is nearly allied to the 4. compressa of the Indian Oolite, but is much more convex;
the beaks are small, but tumid, placed close to the anterior end; the posterior margin is convex. Length one
inch two lines, width one inch four lines.

ASTARTE QUADRATA. M'‘Coy. (PI. XI. fig. 4).

Sp. Ch.—Subquadrate, gibbous; shell thick, marked with strong, concentric, shghtly irregular grooves,
and a few strong, distant wrinkles of growth; anterior end small, rounded; posterior end subtruncate, very
obtusely rounded; beaks obtuse close to the anterior end.

This shell has a thick and somewhat rugged appearance from the prominence of the few large wrinkles of
growth (as distinguished from the transverse sulci), which does not exactly accord with the usual appearance
of the Astarte ; the form too is more quadrate than is usual in that genus, which is, nevertheless, the most ap-
proximate group in which to place it. Length one inch one line, width one inch six lines.

Cyprina Ecrrton1. M'Coy. (Pl. X. fig. 9).

Sp. Ch.—Orbicular, convex; shell very thick; edge obtuse; surface covered with close, rounded, concen-
tric ridges.

This shell is so closely allied to some of the recent species, and to others found in the tertiary beds of Italy,
that, were it not for its geological locality, it would be difficult to distinguish it as a species; from all fossils of the
Palxozoic rocks, it is distinguished at a glance. The general form is nearly orbicular, and marked concentrically
with close, cord-like striz, as in most of the genus, these strie are slightly irregular in size. Length three
inches three lines, width three inches eight lines.

SYNOPSIS OF THE CHARACTERS OF THE

Or
for)

Donax primiceNntus. M‘Coy. (Pl. X. fig. 7).

Sp. Ch.—Transversely trigonal, gibbous; anterior end short, obliquely truncated, beaked; posterior side
elongate, rounded; a deep, angular sinus in the palleal impression.

This curious fossil is a perfectly formed Donaz ; the anterior end is truneated near the beak, but produced
into a short pointed beak inferiorly; there is a very deep, angular sinus in the palleal impression, which, in the
specimen figured, is well preserved. Length four lines, width seven lines.

Carprum orpicutarE. M‘Coy. (Pl. XII. fig. 7).

Sp. Ch.—Shell depressed, orbicular; posterior side a little longer than the anterior; anterior and posterior
ends subtruncate, rounded, equal; beaks prominent, subcentral; surface smooth, with a few concentric striz.

To most of the species of Cardium this species 1s extremely dissimilar, from the thinness of the substance
of the shell, the concentric markings, and general form. I think, however, it bears a closer resemblance to
the Cardium Grenlandicum, forming the genus Aphrodita and Acardo of different authors, than any other
shell with which I am acquainted, nor do I see any thing to discountenance the idea of their generic affinity.
Length two inches four lines, breadth two inches six lines.

CARDIOMORPHA AXINIFORMIS. Phil. sp.

Tsocardia axiniformis. Phil. Geol. York.

Sp. Ch.—Transversely ovate, depressed, smooth ; beaks prominent, incurved; anterior side very short,
rounded; front margin much curved, sharp; posterior side compressed, obliquely truncated, defined by a ridge
from the beak.

This species much resembles an Axinus in its depressed, hatchet-like form, and obliquely truncated, com-
pressed, posterior side; the large, incurved beaks, however, approximate it more to Lsocardia or Cardiomorpha.
Leneth one inch, width one inch six lines.

te} ?

CarpromorPHa corrucaTa. M*‘Coy. (Pl. VIIL fig. 15).

Sp. Ch.—Transversely oblong, outline ovate in the adult, orbicular in the young shell; anterior side very
small; posterior side lengthened, rounded ; anterior and posterior sides deeply corrugated ; rugze obsolete in the
middle.

This handsome shell is a much larger species than the JZ. oblonga, Sow., frequently attaining a size of
six or seven inches in its greatest diameter. The deep, concentric ruge distinguish it from the other species:
there are about twelve on a moderate sized specimen, but only four or five on a young orbicular one. Length
two and a half inches, width three inches eleven lines. (Small specimen).

CARDIOMORPHA OBLONGA. Sow. SP.
Isocardia oblonga. Sow. Min. Con.—Isocardia oblonga. Phil. Geol. York.—Cardiomorpha oblonga. Koninck. Fos. Bel.
Sp. Ch,—Transversely ovate, diagonally gibbous, smooth; beaks large, prominent, incurved ; anterior end

very small, rounded; posterior side large, subquadrate, hinge-line straight. Length one inch eight lines, width
two inches eight lines.

CarpiomorPHa ventricosa. M‘Coy. (Pl. XIIL fig. 3).
Sp. Ch.—Transversely oblong, subquadrangular, diagonally gibbous, very ventricose, the depth being
equal to the length; anterior side small, the beaks curved into it; posterior end subtruncate; dorsal and ventral
margins parallel; surface smooth.

CARBONIFEROUS FOSSILS OF IRELAND. 57

At first I imagined this to be only a monstrous variety of the Cardiomorpha oblonga, but I have since seen
other specimens, perfectly similar, and I am assured they are not uncommon in the Cork limestone. It is
much more gibbous than that species, and most so in young individuals, the margin being abruptly deflected
in specimens of one inch in width, so that in large specimens the marks of growth are very prominent, that
nearest the beak being raised nearly half an inch above the surface; nearer the margin, the second mark is
less prominent, the third still less, and so to the edge; the surface is quite smooth, except towards the margin,
where it is striated concentrically. Length one inch; width one inch five lines; depth one inch six lines.

Pievuroryncuus. Phil.

Gen. Ch.—Shell fusiform; posterior side produced, rounded, gaping; anterior side truncated, often pro-
tected by an extension of the shell at the keel which bounds it, produced near the beaks into a long, slender tube.

No generic characters having been originally given for the genus Pleurorynchus, must surely have been
the reason why this excellent genus has not been more generally adopted. As both Goldfuss and Mr. Sowerby
continue to place these shells in the genus Cardium, I may be pardoned for furnishing generic characters of my
own, and also a few details as to the structure of the perfect shells, which, I believe, have not come under the
notice of preceding writers. All the species of Plewrorynchus are more or less fusiform shells, subtruncate at the
anterior end; the body of the shell is large and gibbous; the posterior side is rather suddenly attenuated, rounded
at the end, and gaping widely, resembling, in fact, the corresponding part of a Pholas dactylus ; the anterior
side is truncated, bordered by a shelly margin, varying in depth according to the species ; near the beak, a long
slender tube extends to a length often exceeding the length of the shell. The substance of these curious shells
is exceedingly thick, finely striated on the outside, but strengthened internally by strong, radiating ribs, and
presenting internally a cellular structure. The wide gaping of the posterior end shews, that like the Mya
truncata, or the Pholas alluded to, it must have lived habitually buried in the sand, with its long siphons
reaching to the surface. The resemblance to Cardiwm (or rather Hemicardium), seems to be one merely of
general resemblance, and entirely at variance with the true structure of the genus, as seen in the figure of P.
fusiformis, M‘Coy. Professor Agassiz’ reference of the genus to the Brachiopoda is, I confess, quite unintelli-
gible, the Brachiopoda being essentially equilateral, from their structure, and the Pleurorynchi remarkably in-
equilateral; neither does its reference to the Rudistes, from the microscopic structure of the shell, seem more
tenable, the structure alluded to being present in several other shells. Its true station seems to be between
Mya and Pholas.

PLEURORYNCHUS ALIFORMIS. _ Sow. SP.
Cardium aliforme. Sow. Min. Con. and Geol. Tr.—Pleurorynchus aliformis. Phil. Geol. York.—Cardium aliforme.
Gold. Pet.

Sp. Ch.—Heart-shaped, gibbous; anterior side convex from the keel, which borders it, gradually rising to
form the conical, anterior tube; posterior side rather short, conoid; surface, with radiating ribs, nearly equal on
all parts of the shell.

This species is readily known from the P. minaz, by its anterior side rising at once into a conical umbo,
not exhibiting the central concave space of that species; the radiating ribs also are of nearly the same size on
the anterior end as on the body of the shell in this species, in which it also differs from the P. minaaz. This
species is very rare in the carboniferous limestone, where the other is abundant, this being, on the other hand,

common in the inferior slates. Length five lines, width ten lines.

Prevroryncuus ARMATUS. Phil.
Pleurorynchus armatus. Phil. Geol. York.
Sp. Ch.—Aliform, anteriorly subtruncate, produced into a slender tube, equalling or exceeding the pos-
terior side in length; posterior side one-third longer than the length of the shell, compressed; surface re-

cularly striated from the beaks.

1

58 SYNOPSIS OF THE CHARACTERS OF THE

This species is very closely allied to the young of P. aliformis, but is apparently distinguished by the great
length of the anterior tube.

PLEURORYNCHUS FUSIFORMIS. M‘Coy. (PI. IX. fig. 3).

Sp. Ch.—Transversely fusiform; posterior extremity narrow gaping; anterior extremity gibbous; the
margin much prolonged, pointed ventrally, with an inflexed edge, forming a very deep, anterior chamber
round the truncated, anterior face, from which the slender, conical tube rises abruptly; surface finely striated
concentrically ; lips rugose; internal longitudinal ribs large, strong, and sharp.

This splendid species vies with the Plewrorynchus giganteus, M‘Coy, in size; it is distinguished from
it, and, indeed, all others, by its fusiform contour, produced by the contraction of the anterior margin, the
edge of which is suddenly inflexed to about half an inch in width; the substance of the shell is amazingly
thick, half an inch being the usual thickness of adult specimens; the surface is concentrically striated from the
beak; these stria become very large andrugose near the edge, owing to the thickening of the lips in old spe-
cimens; internally the surface is strengthened by large ribs from the beak; the posterior half of the shell is
narrow, compressed, round at the end, and gapes very considerably. Length three inches and a half, width
from the ventral edge of the keel to the posterior extremity, five inches five lines.

PLEURORYNCHUS GIGANTEUS. M‘Coy. (PI. IX. fig. 1).

Sp. Ch.—Cordate, obtusely pointed in front, very much depressed, posterior side suddenly contracted,
very short, rounded, gaping; marginal keel of the anterior side long, thin, simple at the edge; anterior face
conoid, nearly smooth, rising regularly from the margin to the base of the anterior tube, which rises abruptly
at a considerable elevation from the beaks; surface nearly smooth, obsoletely striated transversely ; the contracted
posterior end marked with strong ridges from the beak.

This is one of the largest known species of Pleurorynchus. Length from the posterior extremity to the
beaks about one inch four lines, from the same point to the extremity of the front margin four and a quarter
inches, width of the keel three and a half inches.

PLEeuRORYNCHUS Hipernicus. Phil.

Cardium Hibernicum. Sow. Min. Con.—Pleurorynchus Hibernicus. Phil. Geol. York.

Sp. Ch.—Horsehoof-shaped, anterior end truncated, nearly flat, rising abruptly into a slender, lengthened
tube near the hinge; the edge which bounds the anterior face is produced, parallel to the body of the shell, so
as to form a deep shelly border to the anterior end; body of the shell conical ; posterior end cylindrical, produced.

This species, from its resemblance to a horse’s hoof, is well known to our quarry men by the name of
“ foal’s foot,” and is much prized from the ready sale they get for them.

The tube which issues from the anterior side is as thick as a crowquill, and about four inches long; the
posterior end forms a much thicker tube about two inches long, and gaping at the end like a Pholas, the por-
tion of the shell which projects all round, beyond the margin of the truncated anterior face, is about as deep as
from the same point to the base of the posterior tube; it is usually broken off; the surface is delicately striated ;

the anterior face is nearly smooth, except in the centre, where there are about a dozen concentric ribs. Length
two inches three lines.

Prevroryncuus inriatus. M‘Coy. (Pl. IX. fig. 2).

Sp. Ch.—Body of the shell very gibbous, recularly ribbed from the beak; anterior face convex, inflated,
smooth, or marked only by lines of growth, separated from the body of the shell by a short, obtuse keel; ante-
rior tube very long, cylindrical, smooth.

CARBONIFEROUS FOSSILS OF IRELAND. 59

This species is allied to the P. minax, Phil., but is distinguished by its more gibbous, and smooth, convex,
anterior end. The anterior keel of this shell is interesting from its small size. Length from the beak to the
opposite margin seven lines.

PLEURORYNCHUS MINAX. Phil.

Pleurorynchus minax. Pil. Geol. York.—Pleurorynchus minax. Phil. Pal. Fos.—Cardium aliforme. Var. Gold. Pet.

Sp. Ch.—Heart-shaped, gibbous; anterior side with a large, concave, central space; posterior side rather
short, rounded; shell marked with nearly equal ribs, radiating from the beak, those within the concave anterior
space much finer than the rest.

There appears to be much objection on the part of both British and foreign authors to admitting this as a
species distinct from the Cardium aliforme of Sowerby; it is, however, easily distinguishable by the concave
space in the anterior side, with its enclosed ribs, which are not more than half the thickness of those on any
other part of the shell. Length nine lines, width one inch nine lines.

PLeuroryNcuus NopuLosus. M*Coy. (Pl. IX. fig. 4).

Sp. Ch.—Conoidal; anterior face subtruncate, cordate; posterior side elongated; anterior keel obtuse,
nodulous; surface with obsolete, longitudinal, and transverse, obtusely rounded ridges.

This small species is easily recognized by the keel which bounds the anterior face, being obtusely tuber-
culated or nodulous. Length three and a half lines, width (not including the anterior tube) about three lines.

PLEURORYNCHUS TRIGONALIS. Phil.

Pleurorynchus trigonalis. Phil. Geol. York.

This species differs almost solely from the P. Hibernicus in having the posterior side much shorter, or, if
placed resting on its anterior face, it would be said to be more depressed. Length one inch four lines.

Cypricarpia ALATA. M<Coy. (PI. X. fig. 4).

Sp. Ch.—Transversely trigonal, diagonally gibbous, beaks small, curved, prominent; anterior side narrow,
rounded; a slight sinus in front; posterior side dilated into a flat, rectangular wing; hinge-line as long as the
shell is wide.

This species is unlike any other of the genus with which Iam acquainted: it forms a passage to Avicula.
Length five lines, width eight lines.

CypRIcARDIA conciInnA. M‘Coy. (PI. VIII. fig. 24).

Sp. Ch.—Transversely oblong, twice and a half as wide as long, diagonally gibbous; beaks moderate,
close to the anterior end; anterior end very short, rounded, tumid; posterior side lengthened, equally broad
throughout, abruptly truncated at the end; a strong, rounded ridge extends from the beak to the posterior-
inferior angle; surface sharply striated, parallel to the margin.

This little shell is remarkable for its great transverse length, and the abrupt or rectangular termination of
the posterior end, the points of the angles being rounded. Length one and a half lines, width four lines.

CypricarpiA cunnaTa. MM‘Coy. (Pl. VIII fig. 25).

Sp. Ch.—Transversely oblong, rather more than twice as wide as long; very gibbous, especially towards
the anterior side and beaks, which are very large and tumid; anterior side very short, rounded; posterior side

60 SYNOPSIS OF THE CHARACTERS OF THE

produced, flattened, abruptly truncated at the end, which is rectangular; hinge-line equal to the width of the
shell; surface transversely striated; posterior slope striated parallel to the truncated margin, and with several
waving strie parallel to the hinge-line.

This curious little shell bears much resemblance to one of Professor Phillips’ figures of the Sanguinolaria
sulcata, Mist. (not of the Geol. of York.), from which it is distinguished by the length of the hinge-line,
close, regular striation, great convexity, and the shortness of the anterior side. The striz parallel to the hinge-
line, very great convexity of the anterior side, and the compressed, wedge-like form of the posterior extremity,
are remarkable in the present species. Length three and a half lines, width seven lines.

Cypricarpia cytinprica. MCoy. (Pl. VII. fig. 23).

Sp. Ch.—Transversely elongated, three times as wide as long, cylindrical, very convex; anterior end
short, rounded; posterior end obliquely truncated, obtuse; front margin entire, without sinus, parallel with the
dorsal margin.

The hinge-line is about three-fourths the length of the shell, and parallel with the front margin, which is
entire. Length four lines, width eleven lines.

CyYPRICARDIA MODIOLARIS. M‘Coy. (Pl. VIII. fig. 27).

Sp. Ch.—Transversely oblong, diagonally gibbous; beaks very small; anterior end tumid, rounded;
hinge-line rather more than two-thirds the width of the shell; posterior end angulated, oblique, very obtusely
rounded; posterior slope very obtusely rounded; abdominal margin slightly concave; surface with nearly ob-
solete concentric wrinkles of growth.

This species has much of the general form of the C. impressa, Sow., but the beaks are smaller, the ante-
rior end rounded instead of being truncated, as in that species; the hmge-margin more elevated, and the poste-
rior slope and extremity more obtusely rounded; it also resembles some specimens of the Pullastra complanata,
Sow., but has not the narrow, beaked posterior extremity, has a much smaller anterior side, and is otherwise
different. Length five and a half lines, width one inch one line.

CypricarpIaA opLtonea. ‘Coy. (Pl. VIIL fig. 21).

Sp. Ch.—Transversely oblong, three and a half times wider than long, obtusely keeled; anterior end
short, rounded, a shallow sinus in the front margin, hinge-line about half the width of the shell; surface smooth,
with a few obscure undulations at the posterior end. The hinge-line of this species in shorter than is usual in
this genus, which, with the very elongate figure, will distinguish the species ; from the shortness of the hinge-

line the posterior end is very obliquely truncated, this portion of the shell is marked by a few broad, obscure
undulations. Length six lines, width one inch seven lines.

CypRICARDIA QuADRATA. M‘Coy. (PI. VIIL fig. 22).

Sp. Ch—Subquadrate, gibbous, obtusely keeled, anterior side very short; subtruncate, rounded, posterior
side square; hinge-line straight, as long as the shell is wide, front with a short sinus, from which a concave
space extends half way to the beak; surface with faint, rather distant, concentric striz.

This species bears a slight resemblance to the Cypricardia retusa of the Silurian rocks, but is easily dis-

tinguished by the form of the anterior side; its quadrate, gibbous form distinguishes it from most others.
Length six lines, width eleven lines.

CARBONIFEROUS FOSSILS OF IRELAND. 61

CyYPRICARDIA RHOMBEA. Phil.
Cypricardia rhombea. Phil. Geol. York.

I have only seen imperfect fragments of this shell; it is transversely oblong, with a very strong, diagonal
keel; the dorsal and ventral margins parallel; posterior extremity truncated nearly at right angles with the
hinge-line, which latter is nearly as long as the shell is wide.

Cypricarpia sinuaTa. M‘Coy. (Pl. VIII. fig. 26).

Sp. Ch.—Transversely ovate, obtusely keeled, anterior end very small, rounded, a distinct smus in the
ventral margin, surface smooth; width less than three times the length; hinge line two-thirds the width of
the shell.

This species is allied to the Cypricardia oblonga, but is much less transverse, has a longer hinge, larger
abdominal sinus, and more obtuse posterior end; there are a few obscure concentric undulations visible towards
the posterior end. Length five lines, width one inch three lines.

Cypricarpia sociauis. M‘Coy. (Pl. VIII. fig. 12).

Sp. Ch.—Twice and a half as wide as long, gibbous; dorsal and ventral margins parallel; beaks prominent,
close to the anterior end; anterior side short, rounded, separated from the body of the shell by a deep sinus in
the front margin, from which a broad, shallow sulcus extends obliquely to the beak; posterior end obliquely
subtruncate, rounded; surface marked with strong, irregular, transverse striz. Length four lines, width nine
lines.

CypricarpiA TumIpA. M‘Coy. (Pl. VIII fig. 13).

Sp. Ch.—Transversely ovate, gibbous, length two-thirds the width, smooth; beaks very large, tumid, close
to the anterior end; anterior side short, rounded; posterior end rounded, not distinguished from the body of
the shell.

This little species has much the aspect of the C. semiculeata, but is less wide, the posterior end much broader,
and the surface is entirely devoid of transverse sulci, neither is there any furrow from the beak to the front
margin. Its great convexity, shortness, and smooth surface, distinguish it from any of the allied species.
Length four lines, width five lines and a half.

Sepewicnia. AM‘ Coy.

Gen. Ch.—Equivalved, or nearly so, inequilateral; shell very thin, inflated ; dorsal and ventral margins
subparallel; anterior half of each valve marked with strong, transverse ridges; posterior half smooth; beaks
moderate; anterior side very short, round; posterior side broad, lengthened, subtruncate.

The genus Sedgwickia (M‘Coy) is composed of a very elegant little group of shells, having analogies which
place them, as it were, between the so-called Cypricardie of the older strata, the Avini (Sow.), and the Lep-
todomi (M‘Coy). The passage to Cypricardia is marked by such shells as the Sedgwichia minima, M‘Coy,
and §. corrugata, M‘Coy, while an approach to the same form is indicated by such species of Axinus as the
A. obovata (M‘Coy), and the A. obliqua (M‘Coy), which, however, still retain the oblique, acutely angular pos-
terior side, and very short, oblique, hinge-line of Axinus, and which distinguishes them at a glance from the true
Sedgwickia’s, all of which have a broad, subtruncate, posterior end, and a hinge-line nearly as long as the shell.
They are entirely without hinge teeth, their hinge resembling that of Thracia.

Q

62 SYNOPSIS OF THE CHARACTERS OF THE

These beautiful shells are remarkable for having the anterior half of their valves marked with strong, trans-
verse ridges, and the posterior half perfectly smooth; besides this circumstance they are distinguished from Cy-
pricardia, with which I formerly arranged them, by the thinness of their shells. They seem to have much the
habit of Saxicava, Lam., or more properly, perhaps, of Leptodomus, M‘Coy. Ihave dedicated this genus to
Professor Sedgwick.

Sepewrcnra arrenvatTa. M‘Coy. (Pl. XI. fig. 39).

Sp. Ch.—Transversely ovate, convex ; beaks large, compressed ; anterior side very short, rounded ; poste-
rior side narrow, lengthened, subtruncate, rounded ; hinge-line as long as the shell is wide ; anterior side and
middle of the shell marked with about fifteen strong, transverse ridges, remainder of the surface smooth.

This shell resembles the S. budlata, M‘Coy, but is less convex, larger, and has a longer hinge-line, in con-
sequence of which the truncation of the posterior end is not at all oblique; it also resembles the S. gigas,
M‘Coy, but is much smaller, has much fewer transverse ribs, and is more elongated transversely. Length seven
lines, width eleven lines.

SepGwick1A BuLLATA. M‘Coy. (Pl. VIII fig. 19).

Sp. Ch.—Transversely oblong, very gibbous, length about two-thirds the width; anterior side short,
rounded; hinge-line nearly as long as the shell is wide; posterior end slightly oblique, subtruncate ; beaks very
large, tumid; an obtusely rounded ridge, from the beak to the posterior angle; anterior side with strong,
rounded, distant ridges; middle of the shell and posterior side smooth.

The substance of the shell of this handsome species is remarkably thin. Length four and a half lines,
width six and a half lines.

Sepewickia corrucata. M‘Coy. (Pl. VIL. fig. 18).

Sp. Ch.—Transversely elongate, twice as wide as long, gibbous; a strong, diagonal, rounded ridge, from
the beak to the posterior angle; surface smooth, with the exception of four or five strong, transverse wrinkles
on the body of the shell. Length one and one-third lines, width three lines.

SEDGWICKIA GIGANTEA. M‘Coy. (Pl. XI. fig. 40).

Sp. Ch—Rhomboidal, ovate, convex, depressed ; beaks very large, subcentral, nearest to the anterior end;
anterior side rounded, abdominal margin very convex ; posterior side obtusely: rounded, subtruncate ; anterior
end marked with about forty sharp, transverse ridges, remainder of the surface smooth.

This fine shell is very much the largest of the group, and is distinguished besides by the great number of
the anterior sulci. Length one inch nine lines, width two inches nine lines.

Sepewick1a GLoposa. M‘Coy. (Pl. XI. fig. 38).

Sp. Ch.—Orbicular, globose, beaks nearly central; surface smooth, except on the anterior side, which is
marked with short, delicate, transverse ridges.

This small species is remarkable for its orbicular form and great convexity. Length three lines, width
three and a half lines.

Sepewickia minima. M‘Coy. (Pl. VIII fig. 17).

Sp. Ch.—Transversely elongated, subtrigonal, very gibbous; beaks large, prominent; anterior side small,
obtusely pointed; posterior end very broad, subtruncate, rounded; the greatest gibbosity is obliquely from the
beak to the anal angle, but there is no distinct ridge; posterior end smooth, anterior end marked with short,
strong, transverse striz.

CARBONIFEROUS FOSSILS OF IRELAND. 63

This is by a great deal the smallest species of the genus, scarcely equalling in size the numerous Entomos-
traca of the shales in which it occurs, and which it much resembles to the naked eye. Length about one-

twentieth of an inch.

Axinus. Sow.

Gen. Ch.—Axiniform ; posterior side short, rounded, with a long ligament placed in a furrow along the
entire edge ; posterior side produced, angulated with a small lunule under the beak ; surface smooth.

AXINUS AXINIFORMIS. Porth. sp.

Amphidesma axiniformis. Portk. Geol. Rep. (Without references).

Sp. Ch.—Rhomboidal, slightly oblique, depressed ; length and width nearly equal; beaks prominent, acute,
nearly central; anterior side subtruncate, rounded ; posterior side very slightly oblique, convex; an oblique
ridge from the beak to the posterior angle; surface smooth.

This species has frequently a glossy membranous expansion round the margin of the valves, visible on the
shale in which it occurs. Length nine lines, width ten lines.

AXINUS CARBONARIUS. Portk. sp.
Amphidesma carbonaria. Portk, (Without references).

Sp. Ch.—Orbicular, compressed, smooth, or very finely striated transversely ; length five-sixths of the
width; beaks small, central; anterior and posterior sides equal, the latter slightly truncated. Length ten lines,
width one inch.

AXINUS CENTRALIS. M‘Coy. (Pl. XI. fig. 8).

Sp. Ch.—Trigonal, depressed, smooth; beaks central, or nearly so; posterior slope truncated; posterior
end obtusely pointed; anterior side narrow, rounded.

This is distinguished from every other Axinus I know, by its triangular outline, and nearly central beaks;
the body of the shell is flattened, the ventral margin nearly straight, and the surface perfectly smooth. Length
four lines, width five lines and a half.

.

Axtnus petroweEus. Phil. sp.
Cypricardia deltoidea. Phil. Pal. Fos.

Sp. Ch.—Ovate, deltoidal, depressed, smooth; posterior side obliquely truncated, defined by a sharp
angle or keel, extending from the beak to the posterior angle; anterior margin convex.

This species is described by Professor Phillips as a Cypricardia ; he, however, notices the resemblance it
bears to the Azxinus obscurus of the magnesian limestone; the examination of some good specimens leaves
no doubt on my mind that they are of the same genus: the two valves of the present species are usually found
together, and are perfectly alike. Length nine lines, width eleven lines.

Axinus NucuLowes. M‘Coy. (PI. XI. fig. 9).

Sp. Ch.—Transversely ovate, length two-thirds the width, convex; beaks small, one-third the width from
the anterior end, broad, rounded; posterior side attenuated, pointed, extremity rounded; ventral margin

64 SYNOPSIS OF THE CHARACTERS OF THE

nearly straight; surface nearly smooth, marked towards the margin with fine, transverse lines of growth. Length
four lines, width six lines.

Axinus ostiquus. M‘Coy. (Pl. VIIL fig. 29).

Sp. Ch.—Obliquely ovate, convex; beaks large, prominent, close to the anterior end; anterior side very
short, rounded, front margin convex; posterior side lengthened, very obliquely truncated; a strong ridge from
the beak to the posterior angle; surface smooth, except on the short, anterior side, which is marked with fine,
rather distant, transverse strie ; epidermis produced into long fringes beyend the margin,

This species occurs in company with the 4. depressa. A. axiniformis, and A. carbonaria, Portk., from all of
which it is distinguished by its great obliquity, and the inequality of its sides; the transverse striz also appear
limited to the anterior side in the present shell. Length seven lines, width eight lines.

Axinus opovatus. MM‘Coy. (PI. VIII. fig. 30).

Sp. Ch.—Transversely obovate, depressed; beaks large, not prominent, close to the anterior end, which is
broadly rounded; abdominal margin convex, posterior end poimted, equally rounded towards the dorsal and
ventral margins; surface smooth, or with a few regular, concentric striz.

The principal feature in this regularly obovate shell, is the great and equal convexity of the dorsal and
ventral margins as they approach the posterior end, which is thus regularly pointed; the ridge separating the
posterior slope from the body of the shell is very slightly defined. This shell is almost identical in form with
the Lyrodon ovatum of the muschelkalk. Length nine lines, width one inch five lines.

Axinus orpicuLaris. M‘Coy. (PI. VIII. fig. 28).

Sp. Ch—Orbicular, length and width equal, depressed, smooth; beaks small, nearly central; a slightly
marked, rounded, oblique ridge on each side of the beak, that on the posterior side strongest; anterior and pos-
terior margins almost equally convex.

This little shell is distinguished from all the allied species by its nearly central beaks and orbicular outline,
and from the A. carbonaria, Port., by the height of the sides and their more perfectly rounded form.

Length three and a half lines, width four lines.

Dotasra. MM‘ Coy.

Gen. Ch.—Subrhomboidal, gibbous, slightly inequivalve, inequilateral, anterior side rounded, posterior
side subtruncate, generally oblique; shell thick, beaks large, prominent; in the left valve two long, diverging,
cardinal teeth, anterior one longest, and two lengthened, posterior, lateral teeth.

I have found it necessary to frame this genus for the reception of a considerable number of shells of the
Paleozoic rocks, hitherto classed with Lyrodon, Cucullea, Cypricardia, &e. Some few shells of this group
are placed by Goldfuss in the genus Lyrodon, although it is obvious, even from their external form, that they
can have no affinity with the T’rigoni@ of the Oolites; besides which, those last are equivalved, and have
strongly suleated, cardinal teeth, while the Dolabre are inequivalve, and have simple cardinal teeth: from the
Cypricardie they differ in general form, being inequivalve, and in their long diverging cardinal teeth. All the
Devonian Cucullea’s of Marwood belong to this group, the long, anterior, cardinal teeth having been taken
for the prominent edge of the muscular impression, although, as Professor Phillips has observed, it is on the
wrong side of the beak for Cuculiea; the lateral teeth of Cucullea, angusta as figured by Mr. Sowerby, or as
Ihave observed them myself in Irish specimens, do not seem to correspond to those of Cucullea.

CARBONIFEROUS FOSSILS OF IRELAND. 65

DoLABRA ANGUSTA. Sow. sp.

Cucullaa angusta. Sow. Geol. Trans.—Cucullea angusta. Phil, Pal. Fos.

Sp. Ch.—Square, length and breadth equal, very gibbous; beaks large, tumid, central; sides nearly
equal ; anterior side rounded ; posterior side truncated, straight, at right angles with the hince.

DOLABRA COMPLANATA. Sow. Sp.

Cucullza complanata. Sow. Geol. Trans.—Cucullea complanata. Phil. Pal. Fos.

The specimens of this species which have occurred, although numerous and easily identified, are too im-
perfect for description.

Donapra corruGATA. M‘Coy. (Pl. XI. fig. 12).

Sp. Ch.—Transversely trigonal, gibbous, a broad, longitudinal, shallow depression in the middle of each
valve; anterior end short, rounded; posterior side lengthened, narrow, rounded; surface smooth; ridges
strongly wrinkled concentrically ; middle of the shell smooth.

This species is easily known from its congeners by its trigonal form, and the few strong wrinkles which
mark the sides. Length one and a half lines, width two and a half lines.

DoLaBRA EQUILATERALIS. M‘Coy. (PI. XI. fig. 14).

Sp. Ch.—Square, length and width equal, equilateral, gibbous; beaks large, prominent, central; posterior
ridge rounded; posterior margin narrowed, slightly oblique; surface smooth.

In general form this shell bears a strong resemblance to some of the large casts of the L. levigatum of the
Diirrheim Keuper beds. The remoteness of their geological localities will, however, prevent the possibility of
their being confounded; besides which, the present shell is almost perfectly equilateral, the other very inequila-
teral; and the Keuper species has the posterior side very obliquely truncated, while it is very slightly so in the
present species; it differs from the Cucullea angusta, Sow., in its larger beaks, narrow posterior end, and more
depressed form; and from the C. trapezium, in its shorter posterior side. Length one inch five lines, width one
inch five and a half lines.

Dorapra GREGARIA. M‘Coy. (Pl. XI. fig. 11).

Sp. Ch.—Rhomboidal, gibbous; beaks prominent close to the anterior end; anterior side small, rounded,
angulated at the hinge; posterior side dilated into a broad, flattened wing, obliquely subtruncate, rounded ;
body of the shell obliquely gibbous, divided in the middle by a broad, flattened depression, from the beak tothe
front margin, bounded on each side by an obtusely rounded keel; surface marked with a few irregular, trans-
verse striz.

Length two lines, width two and a half lines.

Dotapra Harpinci. Sow. sp.
Cucullea Hardingii. Sow. Geol. Trans.—Cucullea Hardingii. Phil. Pal. Fos.

Sp. Ch.—Transversely oblong, very gibbous; length two-thirds the width; beaks large, tumid, close to the
anterior end; anterior side very short, rounded; posterior side slightly oblique, subtruncate; a diagonal ridge
from the beak to the posterior angle, and one or two others on the posterior slope; surface with obscure, con-
centric lines of growth.

None of the ridges on the posterior side are strongly marked. Length about one inch.

R

66 SYNOPSIS OF THE CHARACTERS OF THE

Doapra orBicuLaRis. M‘Coy. (Pl. XI fig. 13).

Sp. Ch.—Orbicular, depressed, smooth; length and width equal ; beaks central; posterior slope compressed,
posterior ridge obtuse.

This species is remarkable for its nearly orbicular form. In some of the casts the impressions of the car-
dinal teeth are visible. Length five and a half lines, width the same.

DoLaABRA RECTANGULARIS. MM'Coy. (PI. XI fig. 10).

Sp. Ch—Subquadrate, length and width nearly equal, convex ; beaks nearly central, very large, promi-
nent; anterior side obtusely rounded, front margin convex; posterior side short, flat, rectangular, abruptly trun-
cated, separated from the body of the shell by a very prominent diagonal ridge from the beak ; surface
smooth.

This shell much resembles the Cuculle@a angusta, Sow., in géneral form, but is much more depressed,
and is moreover distinguished by its greatly larger beaks, and prominent posterior diagonal ridge; the straight
rectangular posterior side distinguishes it from every species of Cypricardia with which I am acquainted.
Length six lines, width seven lines.

Dorasra secuRIFoRMIS. M‘Coy. (Pl. XI. fig. 15).

Sp. Ch.—Rhomboidal, convex, securiform ; anterior side very short, broad, rounded, front margin convex ;
a slight sinus at the posterior angle; posterior side produced, flattened, obliquely truncated, narrow at the end,
separated from the body of the shell by an obtusely rounded ridge; hinge-line three-fourths the width of the
shell; surface very finely striated transversely. Length ten lines, width one inch two lines.

DoLABRA TRAPEZIUM. Sow. Sp.
Cucullea trapezium. Sow. Geol. Trans.—Cucullea trapezium. Phil. Pal. Fos.

The few specimens which have occurred of this shell are too imperfect for description ; the species re-
sembles the D. Hardingii, but is much longer in proportion to the width, and has the posterior end broader and
more truncate.

DoLABRA UNILATERALIS. Sow. SP.
Cucullea unilateralis. Sow. Geol. Trans.

Sp. Ch.—Obliquely trigonal; beaks large, tumid, nearer to the anterior than the posterior side; hinge-line
short; margin one regular curve from the anterior end to the posterior angle, which is much lengthened, and
having a strong ridge from the beak ; posterior end very obliquely truncated.

Lepropomus. ‘Coy.

Gen. Ch.—Transversely oblong, equivalve, imequilateral; shell very thin, inflated, transversely sulcated ;
beaks large, tumid, obliquely incurved; hinge-line moderate, nearly the length of the shell; anterior side
short, rounded ; posterior side subtruncate; muscular impressions two, distant, lunate.

This genus is proposed to include a number of fossil shells hitherto placed with Corbula, although differmg
from that genus in almost every essential point; in the first place, all the Corbule have one valve much

- smaller than the other, particularly at the beaks, while both the valves and beaks of the present shells are per-
fectly equal; the beaks of Corbula are nearly central and straight, they are close to the anterior end, and

CARBONIFEROUS FOSSILS OF IRELAND. 67

obliquely incurved in the present genus: these fossils resemble the Saxicave, but as a genus they are at once
distinguished by being regular, while the irregularity of form in the species of Saxicava, is so essentially con-
nected with their habits that it becomes of importance; on the whole, the nearest approach among recent shells
to our fossil genus, is perhaps Dr. Leach’s genus Thracia.

Lerropomus Fragiuis. M‘Coy. (Pl. X. fig. 11).

Sp. Ch.—Transversely oval, gibbous; shell very thin; surface with regular, sharp, elevated, concen-
tric stria ; five-sixths of the width; anterior side large, rounded; posterior side slichtly narrowed, subtrun-
cate; beaks large.

This shell is so obviously related to the Corbula gigantea of the Greensand, that I have no hesitation in
placing it im the same genus, at the same time that I do not think either of those shells congeneric with the Cor-
bula of our coasts, and that they should rather form a distinct genus which would be found only in the fossil
state. The present species is very convex; the beaks large, tumid; the shell is exceedingly delicate; the con-
centric striz are extremely regular, small, but sharp and distinct, they are distant and smooth. Length one inch
eight lines, width two inches two lines.

LEPTODOMUS SENILIS. Phil. sp.
Corbula senilis. Phil. Geol. York.

Sp. Ch.—Transversely oval, gibbous; surface with very irregular, transverse wrinkles.

This is easily distinguished from the L. fragilis, M‘Coy, by the thick, rugged, irregular ridges which cross
the surface, instead of the delicate, sharp, regular striation of the latter species; the beaks are very large and
gibbous. Length one inch three lines, width two inches.

VENERUPIS CINGULATUS. M‘Coy. (Pl. X. fig. 1).

Sp. Ch.—Transversely elongate, oval, cylindrical, very convex; beaks close to the anterior side, which is
very small, rounded; posterior side elongated, obliquely truncated, rounded; surface with about ten or eleven
large, angular, concentric ribs, which are sometimes crossed by fine, longitudinal striz.

In this species the concentric ribs are very regular; they are large, angular, and sharp above. Length four
lines, width seven lines.

VENERUPIS OBSOLETUS. M‘Coy. (PI. XI. fig. 16).

Sp. Ch.—Transversely ovate, convex ; surface with about ten obtuse, concentric ribs on the sides, becoming
obsolete on the middle of the shell.

From its strong, general resemblance to the V. scalaris, I have placed this shell in the present genus, rather
than in Pullastra, to which it seems closely allied; the surface is uniformly but slightly convex; the beaks
rounded, but prominent; sides concentrically marked, with slightly convex wrinkles, which disappear before
they reach the middle of the shell; the surface is otherwise perfectly smooth; the form is remarkably rounded
in all its parts. Length seven lines, width eleven lines.

VENERUPIS SCALARIS. MM‘Coy. (PI. X. fig. 6).

Sp. Ch.—Transversely ovate, short, very gibbous; beaks large, prominent, close to the anterior end, which
is small; surface with about ten large, angular, concentric ridges.
This is one of the most strongly-marked fossils of the carb. limestone, and its large, smooth, angular, con-

68 SYNOPSIS OF THE CHARACTERS OF THE

centric ridges serve to distinguish it from the others of its genus; the beaks are large, prominent, tumid; an-
terior side obtusely pointed; posterior end rounded; body of the shell very convex. Length six lines, width
ten lines.

ATRACHIA.

The Atrachia form the second tribe of the Dithyra. They are distinguished anatomically from the
typical group by the mantle being free, and entirely wanting those long siphons, so characteristic of the Macro-
trachia. Most of those shells which possess the power of affixing themselves by a byssus, belong to this tribe, as
Byssoarca, Modiola, Pinna, Pecten, &c.

Nucuta. Lam.

Gen. Ch.—Equivalve, inequilateral, transverse, hinge linear, with a row of sharp angular teeth on each
side the umbones, and a central ligamentary pit.

NucvuLa ATTENUATA. Fem.
Nucula attenuata. Mem. Brit. Anim.—Nucula claviformis. Phil. Geol. York. (Not of the Min. Con.)

Sp. Ch.—Transversely elongated, pear-shaped, gibbous, anterior end rounded, tumid; posterior end com
pressed, attenuated, rounded at the tip; nearly as deep as long, twice and a half as wide as long; the surface
finely striated transversely. Depth three and a half lines, width ten lines.

NucuLa BrrostRATA. M‘Coy. (Pl. XI. fig. 23).

Sp. Ch.—Transversely ovate, evenly convex, beaks small, pointed, rather more than a third of the width
from the anterior end; posterior end rounded, shehtly constricted; anterior end rounded, narrow, subrostrate ;
surface with fine, deep, equidistant, concentric striz, with smooth, flat spaces between them.

This species at first sight seems closely allied to one of the figures of the Sanguinolaria elliptica, Phil., but
is more inequilateral, more finely and regularly striated, the anterior side of the present shell is shorter and
narrower than in that, and finally the posterior side, which is broad and obtusely rounded in the S. elliptica, is
narrowed or subrostrate, like the anterior end, in this, and the hinge-line which is long and straight in the
former, is curved and confounded with the margin of the shell, as in the Nucule in the present species; the
posterior mucronation separates it from the N. brevirostris, Phil. Length five lines, width eight lines.

Nucua Brevirostris. Phil.
Nucula brevirostris. Phil. Geol. York.

Sp. Ch.—Transversely ovate, anterior side produced, contracted, rounded; surface with fine, concentric
striae.

The produced and contracted anterior side, although a very common character among the Nucul@ of the

newer rocks, is very uncommon in those of the carboniferous era, and, together with the short ovate form, will
distinguish this species. Length three lines, width five lines.

Nucura carinata. M‘Coy. (Pl. XI. fig. 21).

Sp. Ch.—Rhomboidal, nearly twice as wide as long; a strong rounded ridge from the beak to the front
margin, from which the sides slope gradually; anterior side pointed, forming with the mesial ridge a nearly

CARBONIFEROUS FOSSILS OF IRELAND. 69

equilateral triangle; posterior side one-half longer, tapering, rounded at the point; margin sinuous; surface
finely striated transversely, with a few deeper lines of growth.

This curious little shell is not unlike that of a T'eredo ; it is exceedingly rare, only one specimen having
as yet occurred. Length two lines, width three and a half lines.

Nucura cravatTa. M‘Coy. (PI. XI. fig. 25).

Sp. Ch.—Transversely ovate, gibbous; twice as wide as long; anterior side obtusely rounded; posterior
end produced one-third longer than the anterior; subtruncate, obtusely rounded; an obtuse ridge extends from
the beak to the posterior-inferior angle; surface marked with somewhat irregular, transverse striz, and broad,
flat, intermediate spaces; a few of the striw deeper than the rest, particularly near the margin.

This species is easily distinguishable from the Nucula attenuata, Flem., and N. acuta, Sow., by the very
obtusely rounded posterior end: in general appearance it comes nearest to the N. claviformis, Sow. (N. ros-
tralis, Lam.), but that is a Lias species, and has a much narrower posterior ridge, and the extremity is abruptly
truncated ; the striz are of a peculiar form in the present shell, appearing as if imbricated with the fine edge
towards the beak. Length four lines, width eight lines.

Nucuna cyuinprica. M‘Coy. (Pl. XI fig. 26).

Sp. Ch.—Transversely elongate, twice as wide as long, very convex, cylindrical, rounded at both extremi-
ties; beaks very small, close to the anterior end; dorsal and ventral margins slightly convex; two long, curved,
diverging, subrostral plates; surface smooth, or with traces of oblique striw towards the margin.

This is one of those very interesting species in which there are well developed internal plates beneath the
beak; the external form is allied to that of the Lithodomi. Length three lines, width six lines.

Nucuta betta. M‘Coy. (Pl. XI. fig. 22).

Sp. Ch.—Trigonal, compressed; anterior side abruptly truncated; posterior end obtusely pointed ; dorsal
and ventral margins slightly convex ; surface smooth, with a few transverse wrinkles of growth.

The triangular, flattened form of this Nucula distinguishes it easily from every other Palzozoic species; the
surface seems to have been smooth, or with one or two faint, distant waves of growth. Length five and a half
lines, width six and a half lines.

Nucuxa Gipsosa. Filem.
Nucula gibbosa. Vem. Brit. Anim.—Nucula tumida. Phil. Geol. York.

Sp. Ch.—Transversely ovate, gibbous; beaks large, tumid; length two-thirds the width, depth of the two
valves equal to the length; surface smooth, with few concentric striz.

This species has been described under the name of N. gibbosa by Dr. Fleming, from the Glasgow coal
field, where it is very common. Professor Phillips subsequently described it under the name of N. tumida,
without allusion to Fleming, whence I conclude that author’s description must have escaped notice; I have,
therefore, restored the original name above. This greatly resembles the recent N. margaritacea of our coasts.
Length four lines, width seven lines.

NucuLa LeIoryNcuus. M‘Coy. (Pl. XI. fig. 27).

Sp. Ch.—Transversely ovate, width rather more than twice the length, convex; posterior end rounded,
gibbous; anterior end produced into a long, narrow beak, rounded at the point; surface marked with strong,
regular, equal, transverse striz, which disappear as they reach the anterior end, leaving the long, beak-like, ante-
rior extremity smooth.

S)

70 SYNOPSIS OF THE CHARACTERS OF THE

This elegant little species resembles the N. acuta, Sow. (not of Portk.), and N. attenuata, Flem. (N. ela-
viformis of Phil.) in general form and striation, but differs in the smoothness of the rounded anterior rostrum ;
it is also analogous to the N. rostralis, Lamk. (N. claviformis, Sow.) of the Lias, but it is distinguished, besides
their geological localities, by the present shell having the anterior extremity pointed, as well as smooth, while
it is distinctly truncated in the former shell. Length one line and a half, width four lines.

NucuLa LINEARIS.
Nucula lineata. Phil. Pal. Fos.

Sp. Ch.—Transversely trigonal, convex; anterior side subtruncate, rounded; posterior end produced,
pointed, extremity rounded; surface regularly marked with strong, concentric stria; between each pair are
three or four finer lines.

This small species is very rare; the two varieties are met with, the one with the larger strie crenulated,
and the other with all the striw plain; both states of surface are occasionally found on the one specimen. The
name lineata having being previously used for another species by Mr. Sowerby, I have modified it as above.
Length four lines, width five lines.

Nucuta Lonerrostris. M‘Coy. (Pl. XI fig. 19).

Sp. Ch.—Transversely clavate; width two and a half times the length; anterior side produced into a very
long, narrow beak, abruptly truncated at the end; posterior side moderate, rounded ; surface very finely striated
transversely.

This beautiful little shell is easily distinguished from the N. acuta, and other claviform species of the Pala-
ozoic period, by its distinctly truncated anterior extremity, in which it approaches the N. claviformis, Sow.,
N. rostralis, Lam.), this latter shell, however, belongs to a different formation, and is, besides, distinguished by
its coarse strix, and is less elongated transversely. Length two lines and a half, width five lines and a half.

Nucuta optonca. M‘Coy. (PI. XI. fig. 24).

Sp. Ch.—Transversely oblong; width twice and a half the length, convex; dorsal and ventral margins
parallel, straight; beaks inconspicuous, close to the anterior end; anterior end small, rounded; posterior end
subtruncate, abruptly rounded; surface smooth.

This shell is distinguished by its great transverse diameter, subtruncate, posterior end, and the parallelism
of the hinge-line and abdominal margin; the posterior end being as wide as any other part of the shell.
There are traces of a subrostral plate, as in the N. cylindrica, M‘Coy, and N. solenoides, Goldf. Length three
lines, width eight lines.

NucuxLa Parties.
Nucula undulata. Phil. Geol. York.

Sp. Ch.—Transversely ovate, depressed, width nearly twice the lencth; beaks small, subcentral; anterior
end rounded; posterior end narrowed, compressed, subtruncate, rounded, defined only by an obtuse ridge from
the beak; surface concentrically striated.

This is a large, depressed species, chiefly remarkable for the obtuse diagonal ridge, which runs from the
beak to the front posterior angle, and its blunt, subtruncated, posterior end; the beaks are more nearly central
than is usual in this genus. As there is already a Nucula undulata in the superior strata, I venture to make
the above alteration in the specific name. Length six lines, width eleven lines.

CARBONIFEROUS FOSSILS OF IRELAND. TI

NucuLa recTANGULARIS. M‘Coy. (Pl. XI. fig. 20).

Sp. Ch.—Subquadrate, very convex, beaks tumid; anterior side very small, rounded; posterior side com-
pressed, rectangular, abruptly truncated ; posterior slope undefined, convex ; surface finely and regularly striated
concentrically.

I have seen indications of the hinge-teeth in this species, as in Nucula; at the same time the elevated
hinge-margin is very unlike the usual appearance of that genus. It is allied to the N. plicata and N. lucini-
formis, Phil., both of which exhibit an angulated posterior side. Every fourth or fifth one of the concentric
striae are deeper than the intermediate ones. Length two lines, width nearly three lines.

Nucuta stixta. M‘Coy. (PI. XI. fig. 18).

Sp. Ch.—Transversely clavate, gibbous; beak nearly central; posterior side obtusely rounded; anterior
side suddenly contracted, forming a short, mucronate beak, rounded at the extremity ; surface very finely striated
concentrically.

This, although perfectly distinct from all the Paleozoic species, bears a remarkable similitude to the N.
gutta, Mister, (N. mucronata, Sow.): that is, however, a well known Lias species. The beak-like anterior
side is very abruptly narrowed from the body of the shell; the transverse striw are very fine. Length three

lines, width five lines.

Nucuna untiaTerauis. M‘Coy. (Pl. XI. fig. 17).

Sp. Ch.—Transversely ovate, convex; beaks large, rounded, terminal; anterior side forming a very small
subrostral lobe; ventral margin very convex; hinge-line straight, two-thirds the width of the shell; posterior
side broad, oval, obliquely subtruncate; surface smooth, with a few concentric lines of growth.

This singular shell is rendered curious by having, in fact, no anterior side, the beaks being large, anterior,
and terminal, as in Modiola, the anterior side forming a small lobe beneath. It resembles the Pullastra anti-
qua, Sow., in form, but wants the elegant striation of that species, and has also a more tumid, prominent beak.

Length four lines, width eight lines.

ARCA CANCELLATA. Jart. Sp.

Arcites cancellatus. Mart. Pet. Derb.—Arca cancellata. Sow. Min. Con.

Sp. Ch.—Nearly twice as wide as long, gibbous; posterior diagonal ridge rounded; surface equally cancel-
lated by coarse, radiating, and transverse sulci; abdominal sinus deep, rounded.

This species is very rare in the Irish limestone; the beaks are large, tumid, approximate; the abdominal
sinus very distinct, and producing a shallow depression down the middle of the shell; the reticulations on the

posterior slope are similar to those on the body of the shell.

Arca rimpriaTa. M‘Coy. (PI. XII fig. 8).

Sp. Ch.—Shell small, very convex, rather more than twice as wide as long; hinge-line equal to the width
of the shell; dorsal and ventral margins parallel; surface transversely imbricated, longitudinally fimbriated ;
posterior margin concave; posterior side defined by a strong ridge from the beak.

This is a very beautiful little species; the lamine of erowth are very thick, giving almost a rugged
character to the shell; each one, to the naked eye, appears delicately fringed ; under the lens this is found to be
produced by a number of little, short, thick ribs, each having a rounded termination at the ventral edge. ‘The
ridge which separates the anterior side is strongly marked, and the whole shell is very convex ; from a slight
projection of the hinge-line, the posterior end appears concave. Length two lines, width five lines. The fossil
appears to be rare, the only specimen I have as yet seen being the one figured.

72 SYNOPSIS OF THE CHARACTERS OF THE

CucuLLtma areuta. Phil.
Cucullea arguta. Phil. Geol. York.

Sp. Ch.—Rhomboidal, gibbous, twice as wide as long ; anterior end short, rounded ; posterior end obliquely
truncate, inferior angle acute; a steep ridge separates the posterior slope from the body of the shell; beaks pro-
minent; surface with regular, transverse, imbricating sulci.

This shell isso oblique, its posterior ridge so steep, and its angles so acute, that, when seen in the masses it
sometimes forms, it resembles an Avicula, and the great regularity of the sulci, which are parallel to the mar-
gin, increases the resemblance; the posterior end is more obliquely truncated than is usual in this genus, and
the ridge and angles sharper and more acute; the beaks are small but prominent. Length five lines, width
ten lines.

CucuLL#A TENUISTRIA. M‘Coy. (Pl. XII. fig. 10).

Sp. Ch.—Subcylindrical, transversely oblong, rather more than twice as wide as long; evenly convex,
finely striated, obliquely from the beaks to the ventral margin; beaks approximate, small, close to the anterior
end; anterior side small, compressed, posterior slope not defined, compressed; dorsal and ventral margins
parallel.

Nearly twice and a halfas wide as long; valves evenly convex, with numerous fine, oblique, anterior striz ;

anterior side very short; no ridge defining the posterior slope, which passes gradually into the body of the shell.
Length one inch, width two inches five lines.

Byssoarca. Sv.

Gen. Ch.—Shell transversely oblong, angulated, hinge-line straight, often eared, teeth small; valves
gaping at the basal margin, leaving a sinus when the valves are closed for the passage of the byssus.

BYssOARCA CLATHRATA. M‘Coy. (PI. XI. fig. 34).

Sp. Ch.—Three times as wide as long, convex, cylindrical, anterior end obtuse, rectangular at the hinge-
line, posterior end rectangular, posterior slope separated from the body of the shell by an obscure ridge; entire
surface reticulated with equal, round, radiating strie, which are about their own diameter asunder, and trans-
verse striz, which are equal to the longitudinal in size and distance from each other.

The peculiar character of this singular species consists in the longitudinal and transverse strie being ex-
actly equal in size and relative distance, the spaces produced by the crossing of those striz are square, at each
intersection a small tubercle is produced. Length three lines, width nine lines.

ByssoaRca cosTeLLata. M'‘Coy. (Pl. XI fig. 36).

Sp. Ch.—Width twice and a half the length, very convex, beaks rather large, prominent, anterior end
short, pointed; posterior end rectangular ; posterior slope separated from the body of the shell by a very steep
ridge; entire surface ornamented with equal, rounded, radiating ribs.

This well-marked species is remarkable for the regular equality of its radiating ribs, which, together with
its great width, will distinguish it from all other Palzozoic species; the sinus in the front is very small. Length
four lines, width eleven lines.

Byssoarca Lancrotata. M‘Coy. (Pl. XI. fig. 33).
Sp. Ch.—Transversely trigonal; width four and a half times the length; hinge-line rather less than two-
thirds the length; anterior end very broad, obliquely truncated, smooth, concave, separated from the body of
the shell by a strong, curved ridge from the beak; posterior end very narrow, the extremity obliquely trun-

CARBONIFEROUS FOSSILS OF IRELAND. 73

cated; body of the shell with narrow, obtuse, radiating ribs, closely ornamented with compressed, transverse
tubercles.

This is one of the most singularly shaped shells with which Tam acquainted, all the usual proportions of
the genus being reversed; it resembles the blade ofa razor in form, the anterior side resembling the broad,
truncated end; the hinge-line at the posterior side is about one-third longer than that of the anterior side
of the beak; the posterior side is, however, very narrow, and almost pointed; the posterior slope is small;
strongly striated across, and separated from the body of the shell by a slight ridge; the anterior space, contrary
to the usual rule, is of great size, concave, and nearly smooth; it is very obliquely truncated, so as to form an
acute angle with the ventral margin; it is separated from the body of the shell by a strong, curved ridge,
the body of the shell is convex, having about thirty-three radiating ribs, closely covered with transverse, com-

giving a reticulated appearance to the surface. Length five lines, width two inches.

pressed tubercles, g

Byssoarca optusa. Phil. sp.
Cucullza obtusa. Phil. Geol. York.

Sp. Ch.—Transversely oblong, gibbous, twice as wide as long; beaks large, tumid; anterior end obtusely
rounded; posterior end oblique, very obtusely rounded; hinge-line three-fourths the length of the shell; sur-
face smooth, with a few obtuse, transverse undulations on the body of the shell, and an obscure reticulation on
the posterior slope; a shallow sinus in the front margin.

This species has a peculiarly blunt aspect from the obtuse rounding of all the angles: even that at the
extremity of the posterior end, which is acute in almost every species of this and the neighbourmg genera, is
here very obtusely rounded; the beak is also large, tumid, and bluntly formed: the front is slightly inflexed,
which produces a few transverse wrinkles on the otherwise smooth body of the shell; from this evidence of an
attaching byssus, I have removed the shell to the genus Byssoarca. Length ten lines, width one inch ten lines,

Byssoarca RETICULATA. M‘Coy. (Pl. XII fig. 9).

Sp. Ch.—Transversely oblong, gibbous; dorsal and ventral margins parallel; beaks moderate, close to the
anterior end; anterior end very short, rounded; posterior end obliquely truncated; posterior slope concave,
separated from the body of the shell by a strong diagonal ridge; entire surface striated longitudinally ; trans-
versely decussated by the imbricating lines of growth, of which those nearest the margin are deep and rugose,
those near the beak nearly obliterated; abdominal sinus large, deep.

This species may be known from the Arca cancellata by the greater transverse diameter, and the fineness
of the longitudinal striw: usually larger than the specimen figured, which was the first obtained. Length ten

lines, width one inch eight lines.

Byssoarca semicostaTa. M‘Coy. (PI. XI. fig. 35).

Sp. Ch.—Width rather more than twice the length, gibbous; anterior end rectangular; posterior end nearly
rectangular, concave; posterior slope with seven or eight coarse, rounded, radiating ribs separated by an obtuse,
oblique keel from the body of the shell, wltich is decussated by very minute, transverse, and longitudinal strie.

This beautiful shell is rendered conspicuous by the large radiating ribs which are on the posterior slope,
while the body of the shell appears nearly smooth, being, however, reticulated by microscopic strie. ‘The valves
are distinctly unequal. Differs from the Nueula radiata, Portk., of the Pomeroy schist, in its rectangular ends
and reticulated body. Length four lines, width nine lines.

CRENELLA acuTirostris. M‘Coy. (PI. XI. fig. 37).
Sp. Ch.—Subrhomboidal, oblique, length and width equal, slightly convex, smooth ; beaks large, promi-
nent, acutely pointed ; anterior side rounded, posterior side obliquely truncated, compressed, posterior ridge

strong, rounded.

ae

74 ; SYNOPSIS OF THE CHARACTERS OF THE

This little species bears a resemblance to some of the varieties of Cucullea unilateralis, Sow., but is much
smaller, more compressed, and is, moreover, distinguished from this and all the other Devonian Cucullea’s by
its narrow, pointed beak. Length four lines, width four lines.

Moprota. Lam.

Gen. Ch.—Transversely oblong; beaks small, not terminal; anterior side small, gaping, to allow the pas-
sage of the byssus; no hinge-teeth. Some of our fossil species, as for instance, the M. microcephala, have
the thin, inflated, rugged shell, and elevated diverging ridges of Lanistes, but retaining the angulated hinge-
line of Modiola, forming a passage from one genus to the other: others shew clearly the teeth of the genus
Brachydontes, Sw., indicating a passage towards Nucula, Lam.

Mopi1oLta AMYGDALINA. Phil.
Modiola amygdalina. Phil. Pal. | Fos.

Sp. Ch.—Transversely ovate; rather more than twice as wide as long; very gibbous; beaks large, in-
curved, terminal; anterior side forming a very small lobe under the beaks; fpestenio side obtusely rounded ;
surface marked with sharp, rather distant, concentric striz.

This curious little species has a small lunette beneath the beaks: the concentric strix vary slightly in their
distance from each other. Length three lines, width eight lines.

Mopiota Aancusta. Portk.
Modiola Macadami var. angusta. Portk. Geol. Rep.

Sp.Ch.—Transversely elongate ; three times as wide as long; very gibbous, cylindrical ; extremities rounded ;
dorsal and ventral margins slightly convex; surface marked with fine, sharp, concentric striz.

Moproxa concinna. M'Coy. (Pl. XI. fig. 28).

Sp. Ch.—Transversely oblong, twice and a half as wide as long; gibbous; dorsal and ventral margins
nearly parallel; beaks tumid, cee to the anterior end; anterior end very short, rounded ; posterior end obliquely
subtruncated ; surface with about nine or ten flat, imbricating lamellew, each fringed by strong, sharp, longitu-
dinal striz, finest toward the anterior end.

This beautiful shell is obviously related to that section of the recent Modiole, with small, tender, yet
rugged shells, destitute of byssus, and living habitually in various species of Aleyoniwm, and nearly allied
animals, of whose existence at the period of ‘te carboniferous limestone, we have no other proof. Length four
and a half lines, width ten lines.

Moprota pivisa. M‘Coy. (PI. XI. fig. 30).

Sp. Ch.—Transversely ovate, twice as wide as long, gibbous, beaks tumid, close to the anterior end ; hinge-
margin elevated, rectangular, as long as the shell is wide; anterior end short, rounded; posterior end subtrun-
cate, rounded; a small notch, or sinus in the abdominal margin, from whence a deep sulcus extends entirely to
the beak; surface very finely wrinkled transversely.

The deep, narrow sulcus, extending from the beak to the opposite margin, and dividing the anterior from
the posterior portion of the shell, distinguishes this little species from any other of the genus. Length one and
a half lines, width three lines.

Mopiona tineualis. Phil.

Modiola lingualis. Phil. Geol. York.

Some obscure specimens of this shell have occurred. They are transversely elongate, about four times as
wide as long; dorsal and ventral mar eins convex ; hinge- line very short, scarcely angulated ; anterior end narrow,

CARBONIFEROUS FOSSILS OF IRELAND. 75

rounded ; beaks very small, not prominent ; posterior end rounded; the transverse stria are scarcely visible on the
sandstone casts which I have seen, but seem to have been distant, and strongest on the posterior slope.

Moprora Macapami. Portk.
Modiola Macadami. Porth. Geol. Rep.

Transversely ovate, gibbous ; shell thin, inflated, marked with rather distant, irregular, deep, concentric
striz ; hinge-margin angulated.
This is a very variable shell, length six lines, width one inch two lines.

Moprona MEGALOBA. MM‘Coy. (Pl. XI. fig. 31).

Sp. Ch.—Transversely ovate, gibbous; beaks small, subterminal; anterior lobe exceeding half the length
of the shell, defined by a strong sulcus from the beak; hinge-line two-thirds the length of the shell, angulated.

This is one of the very few instances in which the true, anteriorly lobed, recent, and Oolitic form of Modiola
has been found in the older rocks. It differs from the M. antiqua, Gold., in being very much narrower
towards the beaks, and in its angulated hinge-margin. From the beak to the posterior extremity five lines;
from the cardinal angle to the opposite ventral sinus three lines.

Moprora patuLta. M*Coy. (Pl. XIII fig. 13).

Sp. Ch.—Lengthened, spatulate, gibbous, smooth; marked towards the margin with numerous, fine,
imbricating lines of growth; dorsal margin evenly convex, without posterior angle; posterior end obtusely
rounded; anterior end forming an obtuse lobe before the beak; ventral margin inflexed, slightly sinuate.

The broad, spatulate form, want of posterior angle, and even convexity of the surface, distinguish this from
every other Palaozoic species. From the beak to the posterior end, two inches two lines, greatest length from
the dorsal to the ventral margin one inch one line. Communicated by Dr. Haines of Cork.

Mopiona scauaris. Phil.
Modiola scalaris. Pl. Geol. York.

Sp. Ch.—Transversely oblong, twice as wide as long, slightly convex; beaks close to the anterior end,
which is very short and rounded; posterior end obliquely subtruncate, rounded; dorsal and ventral margins
parallel; surface marked with distinct, narrow, regularly elevated ridges, separated by broad, flat, smooth

spaces. Width about half an inch.

MoptoLaA SUBPARALLELA. Portk.
Modiola subparallela. Porth. Geol. Rep.

Sp. Ch.—Transversely oblong, diagonally gibbous; dorsal and ventral margins nearly parallel; a slight
sinus in the middle of the ventral margin; anterior and posterior ends rounded, nearly equal ; hinge-line three-
fourths the length of the shell; surface coarsely striated concentrically. Length six lines, width one inch.

Lirnopomus pactyLorpes. M‘Coy. (Pl. XI. fig. 41).
Sp. Ch.—Width three times the greatest depth, cylindrical; extremities obtusely rounded; beaks incon-
spicuous close to the anterior end; surface marked by concentric lines of growth, which, near the beak, are de-

cussated by very fine, oblique, longitudinal strie.
This is one of the most remarkable instances I know of a strong analogy existing between a fossil shell of
the older rocks, and a species at present ving in our seas. So strong is the resemblance which the present

76 SYNOPSIS OF THE CHARACTERS OF THE

fossil bears to the Lithodomus dactylus, Cuv., which perforates the coral reefs of the Indian ocean, that were it
not that the fossil is a little more angulated posteriorly, it would be difficult to distinguish them even as
varieties; the length is rather greater than the depth of the two valves in the fossil species; the shell is very
thin, and the concentric lines of growth obtuse and irregular; the oblique striz from the beak to the ventral
margin sharp, fine. From the cardinal angle to the opposite margin eight lines; width one inch eleven lines.

Lanistes. Humph.

Gen. Ch.—Shell oval, transversely cordiform, ventricose; umbones prominent, with diverging elevated
strie; hinge-margin not elevated or angular; teeth none.

The few mountain limestone shells I have referred to this genus, differ from the recent species in having
the hinge-margin a little more elevated as in Modiola ; they have, however, the rugged, thin, inflated shell and
peculiar aspect of this genus.

Lanistes optusus. M‘Coy. (Pl. XIIL fig. 9).

Sp. Ch.—Transversely ovate, obtusely rounded; anterior end narrow, separated from the body of the
shell by a deep sinus in the ventral margin, from whence an oblique, shallow groove extends to the beak,
behind which the body of the shell becomes suddenly more gibbous; hinge-line short; posterior end broad,
rounded; surface radiated with very numerous, fine, sharp, rough, slightly flexuous striae, frequently interrupted
by irregular wrinkles of growth; the striz are alternately larger and smaller towards the margin of large indi-
viduals, but are equal in size in small specimens.

Distinguished from the L. rugosus, M‘Coy, by its more obtuse form, distinctly lobed, anterior side, shorter
hinge-line, and very much sharper, finer, and more numerous radiating ridges. Length of most perfect speci-
men two lines and a half, width four lines. Imperfect specimens are not uncommon, ten lines in length.

LanistEes RuGosus. M‘Coy. (Pl. X. fig. 8).

Sp. Ch.—Transversely ovate, shell thin, rugged; anterior end very short, rounded; umbones prominent;
posterior side dilated, angulated ; surface with numerous, coarse, flexuous ridges, from the beak to the posterior
margin. Greatest length from the cardinal angle to the opposite margin three lines, width six lines.

Mytitus. Linn.

Gen. Ch.—Equivalve, cuneiform, oblique; smooth; beaks terminal, pointed.

Myvitus comprus. M‘Coy. (Pl. XIII. fig. 12).

Sp. Ch.—Acutely ovate, depressed; beaks terminal, acute, slightly incurved; dorsal margin convex, pos-
terior angle very obtuse; front margin oblique, rounded; anterior face truncate, concave towards the beak;
surface smooth, with a few lines of growth.

This little species differs from the M. priscus of the Silurian rocks, in its more acute and curved beaks, the
greater strength of the ridge bounding the anterior face, its more convex and shorter dorsal margin, and more
oblique front margin. Length eleven lines, greatest width six and a half lines.

Myrtitus Freminer. M‘Coy. (Pl. XI. fig. 29).

Sp. Ch.—Trigonal, length twice the width; hinge-line half the length of the shell, depressed, smooth;
anterior face truncated, bounded by a slightly sigmoidal ridge; beaks acute, terminal, curved towards the an-
terior side; posterior margin convex.

This species, like the Dressina polymorpha, has the truncated anterior face and ridge flexuous or sigmoidal.
Length one inch four lines; greatest width seven lines; depth of anterior face three lines.

CARBONIFEROUS FOSSILS OF IRELAND. 17

InocerAmus. Sow.

Gen. Ch.—Shell thick, inequivalve, triangular, deep ; umbones incurved, lateral; hinge short, formed of

a series of transverse grooves.

INOcCERAMUS AURICULATUS. M‘Coy. (PI. XIX. fig. 5).

Sp. Ch.—Longitudinally oval, gibbous; beaks nearly central ; posterior side expanded, compressed, slightly
oblique; anterior side with a large, square ear, deeply divided from the body of the shell; surface smooth at
the sides, marked with broad, obtusely rounded, concentric wrinkles in the middle.

This species is distinguished from the J. vetustus by the large ear on the anterior side, and nearly direct
hinge-line; it is also less oblique. Length eleven lines, width nine lines, length of hinge-line five lines. The
specimen figured was kindly lent by Dr. Haines of Cork.

INocrRAMUS L&visstmus. M*Coy. (Pl. XIX. fig. 6).

Sp. Ch.—Longitudinally oval, compressed, gibbous in the middle; anterior side compressed, produced
above the beaks into a short, angular wing; beaks small; a lengthened oblique lunette on the posterior side of
the beaks; surface perfectly smooth.

This elegant shell most nearly resembles Count Miinster’s J. inversus of the Eifel, from which it differs in
being much more compressed, the middle alone being convex; in its greater length, very small beaks, and per-
fectly smooth surface. Length two inches eight lines, width one inch ten lines. The specimen was presented

by Mr. Jennings of Cork.

INOCERAMUS ORBICULARIS. M‘Coy. (PI. XIII. fig. 11).
Sp. Ch.—Orhbicular, convex, hinge-line oblique; surface with about fifteen broad, smooth, concentric ribs ;

length and width equal.

The almost perfectly orbicular form, and regular, concentric, flattened ribs, distinguish this from any species
of the genus with which Iam acquainted ; the hinge-line is rather long, oblique; beak one-third the length from
the anterior end; the convexity is much less than in most others of the genus. Length eleven lines, width

twelve lines.

TNOCERAMUS VETUSTUS. Sow.

Tnoceramus vetustus. Sow. Min, Con.—Inoceramus vetustus. Phil. Geol. York.—Posidonia vetusta. Koninck. Fos. Bel.

Sp. Ch.—Ovate, convex ; beaks short, pointed, curved; hinge-line short; surface smooth, with about four-
teen large, prominent, concentric undulations.
This species appears to belong to the chalk genus Jnoceramus, rather than to the Posidonie. Length one

inch nine lines, width one inch four lines.

Posiponta. Gold.

Posidonomya. Bronn.

Gen. Ch.—Obliquely ovate, thin, compressed, concentrically ridged; hinge-line oblique, subauriculated
on each side; beaks subcentral.

It seems exceedingly probable, as M. Deshayes has already suggested, that Posidonia may be the inter-
nal plate of an animal allied to Aplysia. I was particularly struck with the resemblance while dissecting
some large specimens of the Aplysia depilans of our coast this summer: the gill covers of those animals, when
observed in the recent state, or before being dried, are precisely similar to a Posidonia in shape, and with
somewhat similar concentric wrinkles, but more faintly marked; their consistence is intermediate between that

U

78 SYNOPSIS OF THE CHARACTERS OF THE

of thin horn and membrane, bending readily, and without injury in any direction, and capable of receiving
very slight impressions, but with sufficient elasticity to regain its original shape on the pressure being removed.
This seems to have been also the state of the Posidonia, as they impress each other in all directions in the
shales without injury. The fine shales in which they occur must have been deposited in deep water, which is
also the habitation of the recent Aplysie. The large, proportionate size of the soft portion of the animal, when
compared with the small shell, would account for the general dark colour of the Posidonia shales. If the above
view were correct, the Posidonie should be removed to the Gasteropoda.

Postponta Becueri. Gold.
Posidonia Becheri. Gold. Pet.—Posidonia Becheri. Sow. Geol. Trans.—Posidonia Becheri. Phil. Pal. Foss.

Sp. Ch.—Obovate, oblique, compressed ; numerous, angular, sharp, concentric ridges ; posterior ear twice
the width of the anterior.

This species varies considerably in its characters; the number of the concentric ribs, and the outline, being
inconstant ; some specimens exhibit delicate strie parallel with the concentric ribs. Length two inches four
lines, width two inches three lines.

PosmonrIA COMPLANATA. Porth.
Posidonia complanata. Porth. Geol. Rep.

Sp. Ch.—Transversely elliptical, compressed ; beaks small, close to the anterior end, which is small,
rounded ; posterior end broader, rounded, ventral margin very convex ; surface striated concentrically. Length
from the beak to the posterior extremity one line.

This little shell belongs very probably to the genus Zsaura, and, if so, it should be removed to the Crustacea.

Postwwonta costaTa. M*Coy. (Pl. XII fig. 15).

Sp. Ch.—Ovate, oblique, compressed, four strong, rounded, radiating ribs occupy the middle of this shell ;
no concentric wrinkles.

This beautiful shell is the only Posidonia I know of without concentric wrinkles, it is rendered very striking
by its four longitudinal, distant, well-defined mesial ridges. Most of the specimens shew a minute oblique pli-
cation of the surface, but as this is not constant in its direction, it is probably due to the folding of the epidermis,
if it had one, or may be due to mechanical causes. Length ten lines, width eight lines.

PoOsIDONIA LATERALIS. Sow.

Posidonia lateralis. Sow. Geol. Trans.—Posidonia lateralis. Phil. Pal. Fos.

Sp. Ch.—Transversely ovate, twice and a half as wide as long; beaks close to the anterior end; surface
with numerous, large, concentric wrinkles.

Portions of this species have occurred in company with the P. Becheri, and P. tuberculata; its great
transverse diameter is the principal character.

PostwontA MEMBRANACEA. MM‘Coy. (Pl. XIIL fig. 14).

Sp. Ch.—Compressed, membranaceous, transversely elongate, recurved; dorsal and ventral margins nearly
parallel; width three times the length; surface with numerous minute, concentric, and longitudinal membra-
naceous wrinkles; hinge-line short, beaks in the centre of it.

This little species is exceedingly distinct from all others of the genus, the P. lateralis is the only one
to which it bears the slightest resemblance, and from it, it is distinguished by being proportionably wider, by
its numerous longitudinal strie, and the minuteness of the concentric wrinkles; it is also much smaller.

CARBONIFEROUS FOSSILS OF IRELAND. 79

The hinge-line is very short and oblique, the beak is placed nearly in the centre of it. From the beak to the
posterior extremity one inch six lines, length six lines. Specimens frequently occur nearly three inches in
their longest diameter; the figure is from a shorter specimen than usual.

Postponta stmiis. M‘Coy. (Pl. XII fig. 2).

Sp. Ch—Obliquely ovate, with numerous, irregular, small, rounded, concentric ridges; beak nearest the
anterior extremity. Length two inches, breadth about one-fourth less.

This species is well distinguished from the P. Becheri, by its small, rounded, cord-like undulations, instead
of the regular, sharp, concentric ribs which mark that species.

POSIDONIA TUBERCULATA. Sow.
Posidonia tuberculata. Sow. Geol. Trans.—Posidonia tuberculata. Phil. Pal. Foss.

Sp. Ch.—Obovate, oblique, compressed; numerous concentric, angular ridges; decussated and tubercu-
lated by four or five longitudinal, radiating ribs from the beak.

This species is scarcely distinguishable from the P. Becheri; the principal character is the existence of a
few longitudinal ribs in the present shell which decussate the concentric ridges, forming tubercles at each of
the crossings; but these ribs are so variable in number and position, and are often so obscure, that it is doubtful
whether they form a good specific character; in some specimens, however, they are very remarkable; the con-
centric ribs are usually fewer and farther apart than in the P. Becheri, but this is a still more variable charac-
ter. Length two inches two lines, width two inches one line.

Posmponra ——— ? (Pl. XII. fig. 3).

This little species was found in company with the P. similis, M‘Coy. It resembles the Posidonia Becheri
in the sharpness of its concentric ribs, but differs from it in having them larger and wider apart, and in having
the beak in the centre of the hinge-line.

Metracrina. Lam.
Margarita. Leach.

Gen. Ch.—Shell rounded, auricles small; umbones sublateral; hinge-line straight, but not lengthened or

oblique; teeth small, tuberculated, obsolete.
I have found it convenient to extend this genus to all those Avicule whose hinge-line is rectangular, and

the general form rounded, thus leaving the true Avicule a very well defined group.

MELEAGRINA ALTERNATA. M‘Coy. (Pl. XIII fig. 17).

Sp. Ch.—Truncato-orbicular, convex; ears large, nearly equal, marked with very strong, concentric striz ;
body of the shell radiated with about eighteen strong, slender, distant ridges, alternately longer and shorter, the
intermediate spaces being marked with rather distant, regular, concentric wrinkles.

In this minute but beautiful shell, the ears are nearly equal in size, one being rounded, the other pointed ;
they are without radiating ridges, but are very strongly marked with rounded, coarse striz, parallel with the

outer margin. Length one line, width one line.

MELEAGRINA EcHINATA. M‘Coy. (PI. XIII fig. 18).
Sp. Ch.—Orbicular, compressed, thin; hinge-line rather less than the width of the shell; anterior ear
equal to the posterior ear in length, narrow, rounded, deeply divided from the body of the shell; posterior ear
undefined, rectangular; surface marked by rather distant, narrow, radiating ridges, strongest towards the mar-

80 SYNOPSIS OF THE CHARACTERS OF THE

gin, which, being interrupted by the scaly lamine of growth, form minute, adpressed spines at the intersec-
tions.

This is one of the thinnest and most delicate of our fossil square Avicule, the concentric lamine of growth
are rather irregular, shewing the fragile nature of the shell at all ages; the narrow threadlike strix being
frequently interrupted by the lamina of growth, give an echinated character to the surface, there is a flat
space behind the hinge, about one line in breadth. Length one inch one line, width one inch one and a half
lines.

MELEAGRINA L&VIGATA. M‘Coy. (PI. XII fig. 5).

Sp. Ch.—Orbicular, oblique, convex, smooth ; posterior ear undefined, rectangular ; anterior ear very
small, deeply divided from the body of the shell.

The smoothness of the surface will at once distinguish this species of Margarita from all its congeners ;
the surface is slightly but uniformly convex; the hinge-line is half the width of the shell, its extremities rect-
angular; anterior ear half the length of the posterior; the anterior side is dilated, so as to give a slight obliquity
to the outline. Length one inch six lines, width one inch nine lines.

MELEAGRINA PULCHELLA. M‘Coy. (Pl. XII fig. 6).

Sp. Ch.—Longitudinally ovate ; hinge short, slightly oblique; ears obtuse; radiating ridges in pairs, plain
on the sides, decussated by concentric undulations, and nodulous in the middle.

This pretty little shell may be known from the other mountain limestone species by its large ribs running
in pairs from the beak to the margin ; they are nodulous only on the convex middle part of the shell, where
also they are crossed by obtuse concentric furrows, becoming obsolete on the sides ; the number of longitudinal
radii about twenty. Length five lines, width five lines.

This is a scarce fossil. The specimen figured is the only one I have seen.

MELEAGRINA QUADRATA. M‘Coy. (PI. X. fig. 5).
Sp. Ch.—Subquadrate, slightly oblique; hinge-line straight; posterior ear twice the length of the anterior
ear, scarcely defined from the body of the shell; surface smooth, with obscure, concentric wrinkles.
This species may be distinguished from the others of the genus by its quadrate form, rectangular ears, and
smooth, obsoletely wrinkled surface. Length five lines, width five lines.

MELEAGRINA RADIATA. Phil. sp.
Avicula radiata. Phil. Geol. York.

Sp. Ch.—Semicireular, hinge-line straight, ears acute ; posterior ear undefined, twice the length of the an-
terior ear; surface with about twenty-five narrow, radiating ribs.

This species differs from the M. tessedlata, chiefly in its smaller size, and the greater number of the radiat-
ing ridge, the posterior ear is also somewhat larger. Length four lines, width five lines.

MeELEAGRINA RIGIDA. M‘Coy. (Pl. XIII. fig. 16).

Sp. Ch.—Longitudinally obovate, convex; anterior ear large, square ; posterior ear about a third longer
than the anterior, pointed; surface with about sixty-five rather distant, narrow, rough, radiating ridges, crossed
by a few large, irregular, concentric wrinkles.

This fine shell runs no risk of bemg confounded with any others of its genus. The specimens obtained
were ofa brilliant, silvery white. The radiating ribs are narrow, rough, and separated by broad flat spaces.
Length one inch nine lines, width one inch ten lines.

CARBONIFEROUS FOSSILS OF IRELAND. 81

MELEAGRINA TESSELLATA. Phil. sp.
Avicula tessellata. Phil. Geol. York.

Sp. Ch.—Semicircular, hinge-line straight, ears acute; posterior ear undefined, once and a half the length
of the anterior ear; surface with fourteen or fifteen distant, rounded, radiating ridges.

This is a very boldly-formed species; the few large, distant, radiating ribs giving it a strongly-
marked character; the spaces between the radiating ribs are smooth, and slightly concave; they are crossed by
distant, imbricating lines of growth; the posterior ear is not distinctly defined from the body of the shell. Length

eight lines, width nine lines.

Preronites. MM Coy.

Gen. Ch.—Equivalve, transversely elongate, very much compressed; beaks small, nearly terminal; ante-
rior side very small; a sinus in the front margin, under the beak; posterior side very wide, subtruncate ;
hinge-line exactly equal to the width of the shell; no hinge teeth.

This genus contains a number of very similar little shells, intermediate in character between Avicula
and Modiola; they resemble Avicula in their very oblique form, large posterior side, and compressed contour ;
but they differ from them in the hinge-line never being extended into a lengthened wing, and in being
equivalve, while their want of cardinal teeth distinguish them at once from the genus Pterinea of Goldfuss ;
the length of the hinge, and compressed, flattened form, distinguish them from the Modiole. The following
species are the only ones I have seen of the genus :

Preronires ancustatus. Af‘Coy. (PI. XIUL fig. 6).

Sp. Ch.—Width three and a half times the length; surface with very obscure wrinkles, parallel with the
posterior margin; anterior end very small, pointed; posterior end obliquely pointed.

This shell is distinguished from the others of its genus by its more slender form; the front margin and
hinge-line form an acute angle, the anterior end being bluntly pointed; the posterior end is also pointed, the
margin rounding directly from the extremity of the hinge-line; the surface has some small, obscure wrinkles

parallel to the posterior edge. Length six lines, width one inch eight lines.

Preronires LAtus. M‘Coy. (PI. XIII. fig. 7).

Sp. Ch.—Transversely triangular, width rather more than twice the length; beaks convex, prominent ;
anterior end small; a distinct sinus in the front margin below the beak; posterior end broad, subtruncate,
slightly emarginate.

This species is well distinguished from the P. angustatus, M‘Coy, by its great length in proportion to its
width: there is an obsolete sulcus running from the beak to the posterior extremity, and obscure indications of
distant striz, parallel to the posterior margin. Length eight lines, width one inch five lines.

PreRONITES sEMIsULCATUS. M‘Coy. (Pl. XI. fig. 32).

Sp. Ch—Transversely trigonal, gibbous; beaks small, tumid, nearly terminal; hinge-line equal to the
width of the shell; much elevated, rectangular; anterior and posterior sides of the shell smooth; about seven
or eight obtuse, rounded ribs extend obliquely from near the beak to the inferior posterior end.

This species is remarkable for having only a few radiating ribs on the middle of the shell, having the sides
perfectly smooth, with the exception of a few delicate lines of growth; the hinge-line considerably elevated and
compressed; the beaks prominent; anterior side very small, tumid; sinus in the front margin moderate. Width
ten lines.

xX

82 SYNOPSIS OF THE CHARACTERS OF THE

Preronites sutcatus. M‘Coy. (Pl. XIII. fig. 5).

Sp. Ch.—Transversely trigonal; anterior end pointed; posterior end broad, subtruncate; a triangular
space extending from the hinge-line to about the middle of the posterior end, smooth; from thence to the front
margin, roughened by about thirteen or fourteen rugged, obtuse ribs.

The strongly ribbed or radiated surface distinguishes this species from the nearly allied Pteronites latus ;
the form is almost exactly that of the P. /atus, the anterior end being, however, more pointed; the beaks
are exceedingly small. Length six lines, width one inch.

Preronites veNTRIcosus. M‘Coy. (Pl. XIII fig. 8).

Sp. Ch.—Transversely elongate, width twice the length, falciform, very gibbous; beaks large, tumid,
close to the small anterior end; hinge-line equal to the width of the shell; abdominal margin very convex ;
surface smooth, or with a few large wrinkles of growth.

This species is so exceedingly ventricose, that the depth of one of the valves nearly equals its length.
Length two lines and a half, width five lines.

PrerInea. Gold.

Gen. Ch.—Transversely elongate, oblique, very inequilateral (equivalve?), hinge-line long, forming a
short wing on the anterior side, and a large, falciform one on the posterior side; cardinal teeth from two to five,
just under the beak, linear, nearly parallel; lateral teeth strong, lengthened, double.

The shells of this genus are much stronger than those of Avicula, and are, moreover, distinguished by their
strong lateral and cardinal teeth; they are said to be equivalve, but such as I have seen were not so.

PTERINEA DESQUAMATA. M‘Coy. (PI. XIII. fig. 2).

Sp. Ch.—Obliquely ovate, convex ; anterior side small, rounded ; posterior slope straight, abruptly marked ;
posterior wing small, faleate, marked with about seven distant, radiating ridges, the spaces between which are
flat and smooth; there is an intermediate finer rib between each of the two upper pair; body of the shell
radiated with about forty-six smooth, equal, narrow ridges, the spaces between which are equal to their own
diameter; between each pair there is one fine, sharp rib.

This approximates to the P. lineata, Gold., but has much finer, radiating ridges, particularly on the pos-
terior wing; there are no concentric scales or striz in the present species. Length nine lines and a half, width

seven lines. Collected by Dr. Haines of Cork.

PTERINEA INTERMEDIA. M‘Coy. (PI. XIII. fig. 1).

Sp. Ch.—Ovato-orbicular, oblique, convex ; anterior ear very small, rounded; posterior ear two-thirds the
length of the shell, pointed; surface entirely radiated with numerous, close, obtuse ridges, alternately larger and
smaller, crossed by rather distant, sharp, imbricating strie.

This interesting species is closely allied both to the P.lineata, and P. decussata, but differs from the former
in being much less oblique, and having a shorter wing, or posterior ear; and from the latter, in having the striz
much finer, more numerous, and unequal in size. Length seven lines and a half, width seven lines. I have
seen fragments of individuals half an inch longer than the above.

Avicuta. Lam.

Gen. Ch.—Shell obliquely oval, inequivalve; hinge margin very much lengthened, and forming narrow,
unequal ears; teeth nearly obsolete.

CARBONIFEROUS FOSSILS OF IRELAND. 83

AvicuLa ancusta. M‘Coy. (Pl. XIII fig. 20).

Sp. Ch.—Obliquely elongate, depressed, nearly three times as wide as long; posterior slope and ventral
margin straight and parallel; posterior slope very slightly marked; a slight sinus in the ventral margin, op-
posite the beak; posterior end obtusely rounded; posterior wing small, falciform, smooth; body of the shell
marked with very delicate, concentric, imbricating striz.

This resembles the Gervillia inconspicua, Phil., but is narrower, and the wing is much smaller, and diffe-
rent in form. Length four lines, width ten lines.

Avicuta Bicostata. M*Coy. (PI. XIII. fig. 26).

Sp. Ch.—Transversely oblong, twice as wide as long, very gibbous; beaks large, tumid; anterior side
short, rounded ; posterior side lengthened, rounded ; hinge-margin pointed, slightly shorter than the shell; a
deep sinus extends from the beak to the opposite ventral margin, bounded on each side by a broad, distinct
flattened mb; entire surface sharply and regularly striated concentrically.

This very beautiful shell is distinguished from all the allied fossils, by the large ribs bounding the abdo-
minal sinus, and the elegant striation of the surface. Length two lines, width four lines.

AVICULA FLABELLULA. M‘Coy. (PI. XIII. fig. 27).

Sp. Ch.—Obliquely ovate, convex; ears small, without radiating strie; surface finely striated from the
beaks; ridges flat, each divided by a fine line in the centre, and separated by a narrow, concave sulcus.

This species is remarkable for the very great width of the front, which is fully double that of the hinge-
line; the beaks are small and prominent; the ears are small, nearly smooth, or with a shght, irregular plication,
parallel to the margin; the surface is very regularly radiated from the beak, with fine, smooth, flattened,
elevated strie, most of which are divided by a fine line about the middle. Length seven and a half lines, width
nine lines.

Avicua cipposa. M‘Coy. (Pl. XIII fig. 25).

Sp. Ch.—Obliquely oval, short, very gibbous; beaks large, prominent, incurved; posterior wing small,
acute, faleate; anterior side moderate, rounded; posterior side semielliptical, abdominal sinus deep; surface
with a few, irregular, obtuse lines of growth.

This little species is chiefly remarkable for the great convexity of its valves; the posterior slope is
gradually rounded; it is less elongated transversely than most of the genus; the posterior, wing-like termina-
tion of the hinge-line has a few coarse striz parallel with the outer margin; the smoothness of the surface is
interrupted by irregular, prominent lines of growth. Length three lines, width five lines.

AvicuLa Inrormis. JM‘Coy. (Pl. XIIL fig. 21).

Sp. Ch.—Transversely trigonal, beaks obtuse, nearly terminal ; anterior end very small; posterior end ob-
tusely rounded ; hinge-line as long as the shell, forming a rectangular, compressed wing; body of the shell very
gibbous; surface smooth, with two or three large, obtusely rounded, concentric wrinkles, most distinct over the

posterior slope.
This little species is not uncommon; its few obtuse wrinkles and general bluntness of form approximate it

to the A. quadrata, M‘Coy, but it is much more transverse, and smaller. Length one line, width two lines. A

very large specimen measures two lines in length, and four in width.

84 SYNOPSIS OF THE CHARACTERS OF THE

AvicuLa LAmMINosSA. Phil. sp.
Gervillia laminosa. Phil. Geol. York.

Sp. Ch.—Very oblique; ears long, anterior obtusely triangular, posterior twice and a half as long as the
anterior, forming a lengthened, narrow wing ; posterior side straight, convex ; surface with scale-like lines of
erowth.

This species has the anterior and posterior ears much larger than the A. lunulata; the flat, perpendi-
cular space which separates the posterior ear from the body of the shell in that species does not exist in this,
the corresponding part being simply convex. Length one inch two lines, width eleven lines, length of hinge-
line one inch seven lines.

AvicuLa LavicaTa. M‘Coy. (Pl. XIII. fig. 23).

Sp. Ch.—Depressed, posterior wing about half the length of the shell ; posterior side slightly curved, convex ;
anterior side very short, rounded; an obtuse sinus in the anterior edge; beak large, prominent, surface smooth.

This fine shell bears some resemblance to the Gervillia lunulata, Phil., it is easily distinguished by its
greater size, smooth surface, and the total absence of the steep, posterior ridge which in that species separates the
ear from the body of the shell; the posterior side is also straighter, and the posterior wing shorter than in that
species ; the surface is evenly convex, and quite smooth; the shell is most convex near the beaks, becoming
flatter towards the ventral margin; the sinus in the anterior side is very wide, but not deep; there are a few in-
distinct lines of growth near the edge. Length two and a half inches, width of hinge-line one and a half inches.

AvVICULA LUNULATA. Phil. sp.
A Gervillia Iunulata. P/zl. Geol. York.

Sp. Ch.—Very oblique, transversely elongate ; posterior side arched, defined from the posterior ear by a
perpendicular, smooth, flat space; posterior ear four times as long as the anterior ear; surface with regular, im-
bricating lines of growth.

This species is rendered very remarkable by the upward curve of the posterior side, which is bounded by a
steeply-inclined, narrow space, separating it from the posterior ear, which latter, when well preserved, forms a
very long, narrow wing; the anterior ear is short and rounded; the surface is marked with regular, imbricated
striz. Length one inch seven lines, width seven lines.

Avicuta recTA. M‘Coy. (Pl. XIIL fig. 24).

Sp. Ch.—Convex, obliquely elongate; posterior side straight, obtusely pointed, separated from the poste-
rior wing by a broad, steep, longitudinally striated space, nearly at right angles with both the wing and body
of the shell; posterior wing half the length of the shell, pointed; anterior wing very short, obtusely pointed ;
posterior wing and body of the shell girt with sharp, close, regular ridges, parallel to the margin.

This beautiful species is distinguished from the Gervillia lunulata, Phil., by the sharpness and regularity
of the transverse ridges, and the straightness of the posterior side; the steeply ridged posterior side distinguishes
it from the others. Length nine lines, width of hinge-line seven lines.

AvicuLa squamosa. Phil. sp.
Gervillia squamosa. Phil. Geol. York.

Fragments of this species have occurred very rarely ; they are distinguished by the broad, regular, seale-
like striation of the surface.

CARBONIFEROUS FOSSILS OF IRELAND. 85

Avicuta THompsont. Porth. sp.
Pterinea Thompsoni. Porth. Geol. Rep.

Sp. Ch.—Transversely elongate, diagonally gibbous; beaks small; anterior wing pointed, separated from
the body of the shell by a small sinus in the front margin, opposite the beak, from whence a furrow extends to
the beak; posterior wing falcate, terminating in a long slender spine; surface with concentric, imbricating
lines of growth.

This is a very distinct and beautiful species, the long, spiniform extremity of the posterior wing is a curious
peculiarity. Length of hinge-line ten lines, from the beak to the posterior extremity five lines.

Avicuta Verneuin. M*Coy. (Pl. XIII. fig. 19).

Sp. Ch.—Transversely subtrigonal; beaks very narrow, small, terminal; posterior side broad, flattened,
forming an obtuse angle at the hinge-line, which is less than two-thirds the length of the shell, and obtusely
rounded at the posterior end ; an obtuse, slightly sigmoidal keel extends from the beak to the posterior extremity ;
surface marked with fine, irregular lines of growth.

This shell is allied to the Avicula Goldfussi, De Ver., and to the A. Saturni, Gold., but is distinguished
from both by its more slender form, shorter hinge-line, and by the posterior end being oval or rounded, instead
of being subtruncate, as in those species; the ridge from the beak to the posterior end is also straighter and
more obtuse in the present shell. Length from the beak to the posterior end two inches two lines, from the
posterior cardinal angle to the opposite abdominal margin one inch.

Pinna. Linn.
Gen. Ch.—Equivalve, triangular; umbones terminal; extremity widely gaping; hinge-margin straight,
teeth none; anterior margin slightly gaping.

PINNA FLABELLIFORMIS. art. sp.

Conch. Pinnites flabelliformis. Mart. Pet. Derb. (C.P.nudus in the Syst. Arrangement),—Pinna costata. Phil.
Geol. York.

Sp. Ch.—Lanceolate, trigonal, narrow, convex; beak and sides of the shell smooth; surface with regular,
narrow, straight ribs, separated by concave, smooth spaces.

This elegant species occurs but sparingly; the nearly parallel, regular, mesial ribs, and the wide, smooth,
intervening spaces, easily distinguish it from the others. As only fragments have come before me, T cannot
give the correct measurements. Professor Phillips’ figure represents the beaked portion, which is deficient in
Martin’s figure, in which latter there is no smooth part shewn.

Pinna Fuexicostata. M‘Coy. (Pl. XIX. fig. 1).

Sp. Ch.— Elongate, triangular, very gibbous; ventral margin smooth or marked with few oblique wrin-
kles; rest of the surface marked with narrow, equal, flexuous sulci, having between them smooth, rounded,
slightly flexuous ridges of unequal width.

From the P. flabelliformis, Mart., this species is distinguished by having the ventral third of the surface
destitute of radiating ribs, aud in the longitudinal ridges beg irregularly unequal in width, and in their beng
flexuous; it differs from the P. inequicostata, Port., in having the two sides similarly marked; from all three
it differs in the longitudinal ridges being flexuous. Length about four inches, width about one and a half
inches.

RE

86 SYNOPSIS OF THE CHARACTERS OF THE

Pinna inxquicostaTa. Porth.

Pinna inaquicostata. Portk. Geol. Rep.

A few fragments, probably referrible to this species, have occurred. It is described as having the radiating
ribs broader on one side than on the other, and the sides smooth.

Pinna mutica. M'Coy. (Pl. XIX. fig. 11).

Sp. Ch.—Cuneiform, four-sided; valves gibbous, obscurely keeled in the middle; surface smooth, with
obscure, irregular, oblique indentations near the margin of the valves.

This species has the ordinary wedge-shaped, four-sided figure of most of the genus, the two dorsal planes
are the narrowest, the mesial ridge of the valves is very obtuse; this scarce species is easily known from the
other Pinne of the Paleozoic rocks, by the plainness of its surface. Length, when perfect, probably about
three inches.

LINGULA.

Gen. Ch.—Longitudinally oblong, equivalve, equilateral ; beaks terminal, pointed, gaping ; front margin
subtruncate, gaping; attached by a fleshy pedicle, passing out between the beaks.

Lincuta MARGINATA. Phil.
Lingula marginata. Phil. Geol. York.

Sp. Ch.—Oblong, twice as wide as long, sides straight, parallel, convex; front margin subtruncate; pos-
terior end obtusely rounded; slightly mucronate in the centre; surface marked with lines of growth parallel
with the margin.

Distinguished from the L. parallela, Phil., by its truncated front, and straight sides. Length half an inch.
Some of the specimens shew traces of the pedicle of attachment.

LINGULA PARALLELA. Phil.
Lingula parallela. Phil. Geol. York.—Lingula parallela. Portk. Geol. Rep.

Sp. Ch.—Oblong, convex, twice as long as wide; sides nearly parallel, slightly convex; front convex;
posterior end elliptical, pointed.

Several specimens have occurred, apparently referrible to this species, but the various fossil species of Lin-
gula are so ill defined, and resemble each other so closely, that without very perfect specimens it is difficult to
identify them.

Lincuna squAmirormis. Phil. ?
Lingula squamiformis. Phil. Geol. York. (?)—Lingula squamiformis. Portk. Geol. Rep.

Sp. Ch.—Oblong, width rather more than half the length; sides straight, parallel; front subtruncate ; pos-
terior end obtusely rounded; slightly acuminate in the middle; convex; depressed towards the front margin ;
surface with irregular, concentric lines of growth.

The specimens corresponding to these described by Captain Portlock are exceedingly abundant in cer-
tain localities. I have never seen a specimen so wide in proportion to the length as that figured by Professor
Phillips; there may, however, be varieties. Length, ten lines, width six lines.

Anomta. Linn.

Gen. Ch.—Shell very thin, irregular, inequivalve, perlaceous, attached by a ealcareous mass passing
through a foramen near the beak of the lower valve, which is flat or concave, the other convex.

CARBONIFEROUS FOSSILS OF IRELAND. 87

Awomia ANTIQUA. M‘Coy. (PI. XIX. fig. 7).

Sp. Ch._—Hemispherical, irregular, convex; margin deflexed; surface of both valves minutely but irregu-
larly wrinkled concentrically ; foramen in the lower valve large, circular.

This interesting shell occurs not unfrequently ; but as the specimens most usually shew only the dorsal
valve, they might be easily taken for a mass of Stromatopora; the irregular shape, and delicate, concentric
plication, heightening the resemblance: the discovery, however, of the perforated, attached valve, which I have
figured, points out its true nature. The shell is very thin. Length one inch, width the same.

MALLeEus orpicuLaris. M‘Coy. (Pl. XIX. fig. 2).

Sp. Ch.—Shell orbicular, slightly oblique, thick, irregular, foliaceous; anterior wing small, rounded at
the extremity, having a deep, angular sinus beneath it for the byssus; posterior wing, with nearly parallel mar-
gins, subtruncate at the extremity ; surface irregularly marked by the imbricating, concentric laminz of growth.

Some of the species of Avicula and Malleus are so nearly allied, that in the fossil state it is sometimes
difficult to distinguish between their genera; in the present instance, however, the great thickness of the foli-
aceous shell, and its ¢rregularity, obviously approximate it to the Linnean Ostree, of which Mailleus is a por-
tion: from all the other species of Malleus it is distinguished by the nearly orbicular form of the body of the
shell. Length three inches, width three inches eight lines; length of hinge-line three inches three lines.

Lima. Linn.

Gen. Ch.—Longitudinally oval, oblique; auriculated valves gaping on one side, near the umbones; with
a triangular disc between the beaks, divided in the centre by a triangular, ligamentary pit; without teeth.

LIMA ALTERNATA. M‘Coy. (PI. XV. fig. 4).

Sp. Ch—Oblong, convex; hinge rectangular, ears slightly rounded, separated from the body of the shell
by a wide, shallow sinus in the margin, and a hollow from thence to the beak; surface entirely covered with
very fine, sharp, undulating strie, alternately larger and smaller.

This species is allied to the Lima prisca, M‘Coy, but is larger, less convex, and much more finely striated.
In the present species the strie are alternately larger and smaller, but perfectly equal, and farther apart in the
L. prisca. Length about eleven lines, width ten les.

Lima concinna. MM‘Coy. (Pl XV. fig. 6).

Sp. Ch.—Obliquely ovate; hinge-line oblique; ears very small, without radiating striz, equal, surface ra-
diated with very numerous, close, fine, flexuous strix, alternately thicker and thinner; the intervening spaces
being less than half the width of the ridges.

This little shell has no very tangible characters, but is, nevertheless, quite distinct from any other mountain
limestone form. The ears are very small, and either smooth or slightly striated parallel with the outer mar-
gin; the valves are nearly convex, and very closely striated, the striz being more nearly equal on one valve
than on the other; the general outline is broadly ovate and oblique. Length five lines, width five lines.

Lima pecussaTa. M‘Coy. (Pl. XV. fig. 3).

Sp. Ch.—Obliquely ovate, lengthened, slightly convex; ears very small, equal; hinge-line oblique; surface
radiated, with numerous unequal, obtuse, smooth ridges, the spaces between which are strongly striated trans-
versely.

88 SYNOPSIS OF THE CHARACTERS OF THE

This rare and beautiful species is easily distinguished from the Devonian Pecten granulosus, Phil., with
which it is alone likely to be confounded, by its very short hinge-line, and by the thickness and inequality of
the longitudinal stria. Length seven and a half lines, width six lines.

Lima tavieatTa. M‘Coy. (Pl. XIV. fig. 3).

Sp. Ch.—Obliquely oval, convex; ears very small, undefined; surface smooth, with regular, obsolete,
concentric undulations.

This is a very scarce species, it is regularly oval in form, the ears being so small as scarcely to interrupt
the regularity of the outline; the hinge-line is oblique, short; the body of the shell concentrically marked with
broad, rounded wrinkles or waves, which are very slightly raised above the surface; to the naked eye, the sur-
face appears smooth, but under a lens is found to be marked with very delicate, waving, longitudinal strie.
Length one inch four lines, width one inch.

Lima optiqua. M‘Coy. (Pl. XV. fig. 7).

Sp. Ch.—Obliquely oval, slightly convex, smooth, marked with few strong, distant lines of growth;
hinge-line very oblique.

The oblique, regularly oval outline, together with its smooth surface, distinguishes this from the other spe-
cies of Lima; the lines of growth are distant, regular, and very strong. Length ten lines, width eight lines.

Lima pranicostaTa. M‘Coy. (Pl. XV. fig. 5).

Sp. Ch.—Obliquely ovate, compressed, hinge-line equal to the width of the shell, ears equal, distinct,
smooth; surface radiated with numerous flat, unequal ribs, separated by very narrow, deep, concave sulci.

This delicate little species is distinguishable by its broad, flat, unequal ribs, they increase in number
towards the margin, and are smooth; the ears are large, the hinge-line oblique; the beaks very small; the
body is evenly, but slightly convex. Length six lines, width five lines.

Lima Prisca. M‘Coy. (Pl. XVIII fig. 6).

Sp. Ch.—Oblong, oval; hinge nearly straight; ears large, rectangular, anterior smallest; surface with nu-
merous, fine, slightly undulating, longitudinal, thread-like ridges.

This remarkable fossil bears a strong resemblance to the recent LZ. fragilis of our coasts. The shell is
thin, and somewhat inflated; surface rugged transversely; from the lines of growth the beaks are small
but prominent, and the ears large; the longitudinal striz sharp and distinct. Length ten lines, width seven

lines.
Lima semisutcaTa. M‘Coy. (PI. XV. fig. 2).

Sp. Ch.—Elongate, oval, depressed; hinge-line short, oblique; posterior ear twice the length of the ante-
rior; surface smooth, with five or six sharp, longitudinal strie in the middle of each valve.

This beautiful little species is easily known by its fine, sharp, mesial ridges, all the remainder of the surface
being perfectly smooth, with the exception of a few, obscure, concentric wrinkles of growth. The general form
is rather depressed, the beak is small but prominent, the ears very short. Length seven lines, width five lines.

Precten. Linn.

Gen. Ch.—Shell regular, depressed, nearly orbicular, auriculated ; umbones central ; ligament small, inter-
nal; hinge-margin short.

CARBONIFEROUS FOSSILS OF IRELAND. 89

Proren mquauis. AL‘Coy. (Pl. XV. fig. 13).

Sp. Ch.—Orbicular, subtriangular, wider than long ; gibbous ; ears unequal, anterior rounded, posterior
pointed, marked with about eight strong ridges, parallel with the outer margin; body of the shell radiated
with about seventeen strong, rough, distant ribs, equal in thickness but alternately longer and shorter, rough-
ened by numerous strong, irregular, concentric wrinkles.

This little species is not remarkable for any very striking character, excepting, perhaps, the equality of
thickness in the radiating ridges, although of unequal length; the only species it approaches is the P. cancella-
tulus, M‘Coy, (Pl. XIV. fig, 9.), from which it differs in the radiating ridges being alternately longer and
shorter, and in the irregularity of the concentric wrinkles. Length two lines, width two and a half lines.

PrcTen asprrutus. M‘Coy. (Pl. XVI. fig. 5).

Sp. Ch.—Orhicular, slightly convex ; ears moderate, unequal, anterior rounded, marked with numerous,
radiating ridges, crossed by strie parallel with the margin ; posterior pointed and similarly marked; surface of
the shell regularly radiated with numerous sharp, tuberculated strix, alternating with which are an equal num-
ber of much finer spinose strix, the spaces between them strongly plicated transversely.

This species approaches the P. rugulosus, M‘Coy, in general appearance, but is distinguished by the trans-
verse striation of the ears, the distinctly tuberculated, radiating ridges, and the intervening spaces, which are
smooth in P. rugulosus, having a distinct concentric plication in the present shell. Length about seven lines,
width seven lines.

PECTEN ARACHNOIDEUS. Phil.
Pecten arachnoideus. Phil. Pal. Fos.

Sp. Ch.—Obliquely ovate, slightly convex ; ears small, nearly equal, acute, smooth, or marked with a few
lines of growth ; surface with few distant, sharp, radiating sulci, forming between them broad, flat, unequal ribs,
crossed by close, fine, concentric striz.

This species occurs of considerable size, but I have not been able to satisfy. myself as to whether the obli-
quity be real or accidental. Length one inch nine lines, width one inch ten lines.

PECTEN ARENOSUS. Phil.
Pecten arenosus. Phil. Geol. York.
Sp. Ch.—Shell subtriangular, convex ; ears large, square, distinct; surface with very numerous, sharp, ra-
diating ridges, alternately larger and smaller, decussated by very fine, concentric strie.
This species has the radiating ribs very numerous and close together, alternately longer and shorter; un-
der the lens they appear regularly reticulated by sharp, transverse lines; the ears are large, rectangular, unequal,
radiatingly striated. Length one inch, width one inch two lines.

Prcren BELLIS. M‘Coy. (Pl. XV. fig. 15).

Sp. Ch.—Ovate, convex; ears moderate, nearly equal, radiated with few, distant, rounded ridges, the in-
tervening spaces being sharply striated parallel to the external margin; body of the shell marked with about
thirty-two sharp, radiating ridges, alternately larger and smaller; interspaces nearly smooth, or faintly marked
by irregular lines of growth.

This little shell approaches the P. gentilis, Sow., very much in general appearance, but has more than
twice the number of radiating ridges, and is shorter in proportion to the width. Length three lines, width
three lines.

PECTEN CANCELLATULUS. M‘Coy. (PI. XIV. fig. 9).

Sp. Ch.—Orbicular, convex; ears large, square; surface with about fifteen thick, radiating ribs, which are
cancellated and tuberculated by thinner, transverse ones.

Z

90 SYNOPSIS OF THE CHARACTERS OF THE

This singular shell is remarkable for the great size and regularity of the radiating ribs; these are slightly
nodulous where they pass over the concentric ribs, which are about half their thickness; the spaces resulting
from the crossing of these two sets of ribs are nearly square; the ears are rather large and rectangular, with
sharp, sigmoidal strie parallel with the margin. Length three lines, width three and a half lines.

PecTEen cincenpus. MM‘Coy. (Pl. XVII. fig. 11).

Sp. Ch.—Truneato-orbicular, slightly convex; ears unequal, posterior very large, rectangular, undefined ;
anterior one small, narrow, smooth; surface with about twelve concentric, angular, smooth ridges, becoming
obsolete on the large posterior ear.

This strongly marked species at first sight bears a resemblance to the P. Sedgewichii, M‘Coy, but it is
smaller, less convex, and has much smaller and more numerous concentric ridges, the ears also are entirely
different. Length six lines, width seven lines.

Prcten cLaturatus. M‘Coy. (Pl. XIV. fig. 12).

Sp. Ch.—Nearly orbicular, convex ; surface with about fifteen strong, radiating ribs, between each pair of
which are three smaller ones, which are cancellated by transverse ribs equalling them in thickness.

This beautiful shell has between each of the fifteen large ribs, three smaller ribs, the centre one of which
is slightly the largest; itis these three smaller ribs only that are crossed by the transverse ridges; those are
placed at such a distance, that the spaces resulting are nearly square: at each crossing of a longitudinal and
transverse rib, there is a swelling or tubercle produced.

PEcTEN c@LATus. M‘Coy. (Pl. XVIII fig. 2).

Sp.Ch.—Shell convex, rounded; length and width equal; about sixty-six close, round, equal, scaly ridges.

A handsome shell, with numerous, close, rounded, radiating ribs, each closely set with small, arched, im-
bricated scales, not distinctly visible without the aid of a lens, surface evenly convex; outline nearly circular.
I have not seen the ears of this species. Length one inch three lines, breadth one inch four lines.

Prcren cocnatus. M‘Coy. (Pl. XIX. fig. 4).

Sp. Ch.—Truneato-orbicular, depressed ; posterior ear pointed, undefined from the body of the shell; sur-
face radiated with about thirty-eight sharp, slender ridges, nearly equal in length and thickness, and separated
by flat spaces twice the width of the ribs, crossed by fine, sharp, concentric strie, about the same distance from
each other as the radiating ribs.

This species resembles the P. megalotis, M‘Coy, but is distinguished by the ears being radiated ; the pos-
terior ear is also shorter and less acute, and the entire shell wider and more depressed in the present species.
Length six lines, width six lines.

Precren comptus. M‘Coy. (PI. XV. fig. 14).

Sp. Ch.—Longitudinally ovate ; ears equal, anterior rounded, with a deep sinus, posterior pointed,
marked with three radiating ridges, crossed by very fine, sharp strie ; body of the shell radiated with about
forty-six distinct, rounded irregular ridges, intervening spaces flat, smooth.

This pretty little shell occurs in great abundance, in company with the P. irregularis, M‘Coy, which it re-
sembles in general size and shape, and in the irregular thickness of the radiating ribs, but has nearly twice the
number of radiating ridges, making it, of course, appear much more finely striated, even to the naked eye.
Length three lines and a half; width three lines and a half.

PrcTEN concavus. M‘Coy. (PI. XV. fig. 10).

Sp. Ch.—Orbicular, wider than long; ears nearly equal; left valve concave outwardly ; covered by about
one hundred and fifty rough, radiating ridges, alternately larger and smaller.

CARBONIFEROUS FOSSILS OF IRELAND. 9]

This large species, like the P. Jacobeus, has the left valve concave outwardly, in which it differs from all
the other Paleozoic species. Length three inches three lines, width three inches eight lines.

PECTEN CONCENTRICO-sTRIATUS. M‘Coy. (PI. XIV. fig. 5).

Sp. Ch.—Transversely obovate, or nearly orbicular, convex ; ears very large, unequal, radiatingly striated ;
anterior narrow, subtruncate at the extremity, deeply divided from the body of the shell; posterior angular,
pointed; surface with delicate, rather distant, concentric striz.

This is a wide species; the ears are large, unequal, and marked with radiating ribs, decussated by the lines
of growth; the surface is marked with rather distant, rounded, concentric strie, the spaces between which are
smooth; the hinge-line in well-preserved specimens is dentated. Length ten lines, width eleven lines.

Prcren conorrus. M‘Coy. (Pl. XVIL fig. 2).

Sp. Ch.—Longitudinally ovate, subtriangular, convex valve very gibbous; ears large, equal, slightly
pointed ; radiating stria numerous, smooth, equal, rounded, about their own diameter apart, spaces between
them flat, smooth.

This species is very inequivalve; the convex valve is very gibbous; the beak large and inflated; the ears
are nearly equal, and without radiating striw. Length one inch, width eleven lines.

PrcTen constmiis. M‘Coy. (Pl. XV. fig. 16).

Sp. Ch.—Elongate, oval, convex, smooth; ears very small, unequal; posterior ear largest, rounded at the
extremity, deeply divided from the body of the shell, and reticulated with strong, radiating, and concentric
ridges, anterior ear very small, rectangular, with transverse striz.

This species closely resembles the large P. elongatus, M‘Coy, and P. depilis, M‘Coy, in form, and in the
small size of the ears; it is distinguished from both, however, by the reticulation of the larger ear. In the
present instance the character is of much importance, as from its general size and form it might readily be con-
founded with the P. depilis. Length three lines, width two lines,

PECTEN DEORNATUS. Phill.
Pecten deornatus. Phil. Geol. York.
Sp. Ch.—Nearly orbicular, flattened; ears small, acute, equal; surface smooth, with uregular, concentric
wrinkles.
This species has very little to attract the attention of the Palxontologist, being neither characteristic of any
particular stratum, or remarkable for its beauty, scarcely even affording a specific character. Length seven
lines, width six lines.

PEcTEN DEPILIS. M‘Coy. (PI. XVI. fig. 11).

Sp. Ch.—Lengthened, ovate, convex, smooth; ears small, unequal, striated parallel with the outer margin,
posterior ear rounded, anterior ear half the length of the posterior, rectangular; hinge-line less than the width
of the shell.

This is one of the very few smooth species of Pecten found in the mountain limestone. Length three
lines, width two and a half lines.

' PecTEN pissmminis. Vem.
Pecten dissimilis. Vem. Brit. Anim. (Not of Phil.)

Sp. Ch.—Nearly orbicular ; right valve slightly convex, with obtuse, alternately larger and smaller, radiating
ribs; the other valve flat, or slightly concave, with sharp, imbricating, concentric striz.

92 SYNOPSIS OF THE CHARACTERS OF THE

The difference between this species and the P. fallax, M‘Coy, is very obvious, both valves being radiat-
ingly striated in the latter, while only one is in the present species. The space intervening between the ribs is
smooth; the ears small.

Pecren pupticicosta. M‘Coy. (Pl. XV. fig. 9).
Sp. Ch.—Longitudinally ovate, depressed ; ears nearly equal, pointed, marked with numerous, close, rough,
radiating ridges; surface radiated with very numerous, close, fine ridges, disposed in pairs.
This species is unlike any other Pecten with which I am acquainted, in the disposition of its stria: when
slightly worn or rubbed, each of the fine, flat, radiating ridges seems doubled, or divided by a fine mesial line.
Length seven and a half lines, width seven lines.

PECTEN ELLIPTICUS. Phil.
Pecten ellipticus. Phzl. Geol. York.
Sp.Ch.—Elongate, ovate, convex, smooth; ears small, equal, square.
This species is distinguished from the P. Sowerbii, M‘Coy, by its smooth surface, and having ears of the
usual form, not raised above the beak of the shell; traces of the colouring frequently remain in this shell;
it seems to have been dark zigzag markings, on alight ground. Length one inch two lines, width eleven lines.

Pecren ELonGATuS. M‘Coy. (Pl. XVI. fig. 9).

Sp. Ch.—Longitudinally oval, length one-sixth greater than the width, convex; surface minutely striated
concentrically ; ears nearly equal, {one square, slightly defined, the other rounded, deeply separated from the
body of the shell.

This fine species appears smooth to the naked eye, but in finely preserved specimens, or with the aid of a
lens, very minute, regular, concentric striz are visible; from the P. Sowerbii, M‘Coy, which has somewhat si-
milar strie, it is distinguished by its greater size, and the form of its ears, while from the P. filatus, M‘Coy,
which to the eye appears nearly as smooth, and has the same general form, it is distinguished by having the
minute striation concentric, instead of longitudinal, as in that species. Length one inch seven lines, width one
inch six lines.

Prcren exicuus. M‘Coy. (Pl. XV. fig. 11).

Sp. Ch._—Longitudinally ovate, slightly convex; ears large, distinctly marked, nearly equal in length, pos-
terior one pointed, anterior one narrow, rounded at the end, deeply divided from the body ofthe shell ; both ears
marked with radiating ridges, crossed by sharp, concentric striae; body of the shell marked with exceedingly
fine, close, radiating striz.

This is the smallest species of Pecten with which I am acquainted; the strie on the body of the shell are so

fine that most specimens appear smooth to the naked eye. It is very common in some localities. Length one
and a half lines, width slightly less.

PECTEN FALLAX. M‘Coy. (PI. XIV. fig. 2).

Sp. Ch.—Nearly orbicular, convex ; hinge-line exceeding the width of the shell; ears unequal; surface of
one valve with numerous rounded, nodulous ribs, alternating irregularly with very thin, smooth ones; interve-
ning spaces striated transversely; the other valve with numerous, radiating, smooth, equal ribs, the spaces
between which are also smooth.

This species is remarkable for the difference it exhibits between the right and left valves, the one
being covered with thick, nodulous, radiating ridges, which even cover the ears; between each pair of those
there is usually a very fine, smooth rib, the intervening spaces being sharply striated across; the opposite valve,
onthe contrary, has much more numerous equal ribs, which, with the intervening spaces, are quite smooth. It

CARBONIFEROUS FOSSILS OF IRELAND. 93

appears to me that Professor Phillips’s figure 19, which he refers with a doubt to the P. dissimilis of Fleming,
belongs rather to this shell; the two species are very distinct. Length one inch two lines, width one inch
four lines.

PrcTen Finatus. M‘Coy. (PI. XIV. fig. 10).

Sp. Ch.—Elongate, ovate, convex ; ears distinct, square, unequal; surface nearly smooth, with very fine,
longitudinal, thread-like strie.

This species is remarkable for its nearly parallel, wire-like strie, which are scarcely visible to the naked
eye; the form is regularly ovate; the ears deeply divided from the body of the shell, large, unequal, rectangu-
lar. Length ten lines, width nine lines.

PECTEN FLABELLULUM. M‘Coy. (PI. XV. fig. 17).

Sp. Ch.—Orbicular, flattened; surface gently undulated by faint, irregular, radiating, rounded plaits,
obsoletely striated longitudinally ; a few distant, sharp, radiating ridges extend from the beak about half way

to the margin.
This beautiful shell is in no danger of being confounded with any other; it resembles an expanded fan, the

surface being marked with broad, nearly obsolete, longitudinal folds, and about eight or nine slender, radiating
ridges extending half way from the beak; under the lens the surface appears very finely and obscurely striated,
Length one inch, width about two lines more.

PECTEN FLEXxuosUS. M‘Coy. (Pl. XVIII fig. 1).

Sp. Ch.—Shell ovate, nearly orbicular, with about forty-five irregular, rounded, flexuous, radiating ribs;
ears small, faleate, pointed, sharply striated, parallel with the outer margin.

The only specimen I have seen of this species is but indifferently preserved; the surface is slightly convex;
the ribs unarmed, radiating in a waved or slightly irregular manner; only one ear remains, small, and somewhat
faleate. Length two inches, width two inches two lines.

PrcTEeN Forsesu. M‘Coy. (Pl. XV. fig. 20).

Sp. Ch.—Orbicular, convex; surface marked with strong, close, radiating ribs, alternately larger and
smaller, cancellated by sharp, concentric ridges; ears small, unequal, one square, undefined from the body of
the shell, the other small, narrow, rounded, marked with a few radiating ridges, and strong strie parallel to the
margin,

This little species is allied to the P. arenosus, Phil., but is more orbicular, and the concentric striz
are coarser and farther apart; the ears also are entirely different in form. Length five and a half lines, width
six lines.

PectEn crpposus. M‘Coy. (Pl. XVIII fig. 5).
Pecten gibbosus. M‘Coy. In Catalogue Geol. Soc. Dublin.

Sp. Ch.—Shell orbicular, very convex, smooth, marked by a few concentric lines of growth; ears nearly
equal in length, posterior ear undefined, rectangular, anterior ear narrow, deeply divided from the body of the
shell, truncate at the extremity.

This little species is almost globular; the small, lengthened ear is perfectly flat and distinctly separated
from the body of the shell. Length seven lines, width the same.

PECTEN GRANOsuS. Sow.
Pecten granosus. Sow. Min. Con.—Pecten granosus. Phil. Geol. York.
Sp. Ch.—Nearly orbicular, wider than long, convex; ears small, unequal, surface with about thirty tuber-

culated ribs, between each of which is a smaller, nearly smooth one.
2A

94 SYNOPSIS OF THE CHARACTERS OF THE

This fine species is one of the largest of the genus found in the carboniferous limestone; the ears extend
nearly the width of the shell, but are narrow. Length one inch ten lines, width two inches (frequently three
inches in length).

PrEcTeN GRANULOosUS. Phil.
Pecten granulosus. Phil. Pal. Fos.

Sp. Ch.—Obliquely ovate, lengthened, slightly convex; ears large, distinct, nearly equal; surface reti-
culated with fine, equidistant, radiating and concentric striz.

This little species resembles a Lima in general form. It is easily distinguished from the other species by
the minute, equal reticulation of the surface. Length six lines, width four lines.

Prcten Harpiner. MCoy. (PI. XV. fig. 18).

Sp. Ch.—Ovato-orbicular, depressed; ears equal, square, radiated with about five or six equal ridges,
crossed by others of equal size, parallel with the outer margin; surface radiated with twenty-two strong, equal,
spinulose ridges, alternating with which are an equal number of much finer strie, also spinulose ; intervening
spaces flat, smooth.

This species is distinguished from the P. interstitialis, Phil., and P. intercostatus, M‘Coy, by having only
one fine rib between each pair of large ones. Length six lines, width seven lines.

Dedicated to Major Harding, who has so materially advanced the knowledge of the fossils of the Devonian
series.

PecTen uians. M‘Coy. (Pl. XVI. fig. 6).

Sp. Ch.—Longitudinally ovate, depressed ; ears small, unequal, a very large fold beneath the posterior ear,
forming a hiatus in the margin; surface with very numerous, rounded, radiating ridges, alternately larger and
smaller, crossed by regular, concentric, imbricating striz.

This shell is rendered very remarkable by the large fold on the posterior side, which, probably, served to
allow the byssus attaching the shell to pass through; the byssus, however, according to this view, must have
far exceeded the size usual in this genus; the ears are very small for the size of the shell. Length two inches,
width two inches two lines.

PectTen incrassatus. M‘Coy. (Pl. XVI. fig. 1).

Sp. Ch.—Orbicular, convex; ears nearly equal, acute; about twenty-five thick, rounded, radiating ribs;
surface with fine, irregular, concentric wrinkles.

This boldly marked shell is easily recognized by its numerous, large, rounded ribs, most of which are con-
tinued distinctly to the beak; they are separated by concave spaces, wider than themselves: the ears are sharply
striated parallel to the margin; the body of the shell has very delicate, short, discontinuous, membranous, con-
centric markings, which become larger towards the margin, where they give the ribs a slightly nodulous cha-
racter. Length one inch two lines, width one inch four lines.

PecTen inornatus. Phil.
Pecten inornatus. Phil. Geol. York.
Sp. Ch.—Ovate, slightly convex ; ears small, equal, nearly square; surface concentrically waved, with ob-
tusely rounded, smooth wrinkles.
This species is usually somewhat less than the P. ellipticus, Phil., from which it is distinguished by the
large, concentric wrinkles on the body of the shell. Length seven lines, width six lines.

CARBONIFEROUS FOSSILS OF IRELAND. 95

Prcren IntERCostatus. M‘Coy. (PI. XVIIL fig. 4).

Sp. Ch.—Shell oblique ; surface with about nine or ten strong, radiating ribs; between these are from three
to nine smaller, the middle one of which is usually larger than the rest; all the ribs have fine, compressed,
hooked spines at regular intervals, which, when broken, give them a tubercular aspect; ears very large, square,
with radiating ridges, and strong spines on the dorsal margin.

This beautiful little shell appears very closely allied to the P. interstitialis, Phil., but the number of small
ribs between every two large ones, instead of being regularly three, is seldom less than five, and as frequently
nine, on the one specimen; the ears also differ materially. It is very seldom that any of the delicate spines are
preserved, the ribs more frequently presenting a roughened or tuberculated aspect. Length six and a half
lines, width seven and a half lines.

PECTEN INTERSTITIALIS. Phil.
Pecten interstitialis. Phil. Geol. York.

Sp. Ch.—Obliquely ovate; ears small, acute; about eighteen sharp, radiating, spinose ribs, in the spaces
between which are three smaller ribs, or striz.

This species has nearly equal, acute ears, which are striated both radiatingly and across; the three elevated
strie between each pair of large, spinous ribs are very regular. Length seven lines, width six and a half
lines.

Prcren rrrecuiaris. MM‘Coy. (Pl. XV. fig. 8).

Sp. Ch.—Longitudinally ovate, or nearly orbicular, convex; ears moderate, nearly equal, marked with
about five radiating ridges, crossed by fine striz, parallel with the outer margin; body of the shell radiated with
about twenty-six flattened ridges, very irregular in thickness and length, intervening spaces smooth.

This little species occurs in company with the P. bellis, M‘Coy, which it much resembles; it is distin-
guished, however, constantly, by the flatness and irregularity of the radiating ridges, which also gives them
the appearance of being more crowded, although really less numerous, than in that shell. Length two lines,
width two lines.

Prcten Jonesu. M<‘Coy. (Pl. XVI. fig. 10).

Sp. Ch.—Obliquely obovate, convex; ears unequal, finely striated, parallel to the margin, anterior largest,
connected with the body of the shell by a flat space, posterior ear slightly pointed; body of the shell with
about twenty-eight narrow, rounded, radiating ribs, three or four times their diameter apart, intervening spaces
smooth, slightly and irregularly wrinkled concentrically.

This species is remarkable for the distinctness of its striation, the slender, radiating ridges being widely
separated, and each continuing distinctly up to the beak; there are no radiating strie on the ears. Leneth
six lines, width seven lines.

Precten Knocxonniensis. M‘Coy. (Pl. XVII. fig. 4).

Sp. Ch.—Longitudinally ovate, convex; valves dissimilar, the one marked with close, fine, smooth, radiat-
ing striz, slightly flexuous, and nearly equal in size, the other radiated with about twelve large, rounded ribs,
each having a very fine, sharp, ridge on each side, each set of three ribs being separated from the next by a
narrow, flat space, all the radiating ridges on this valve are closely set with small, imbricating, scale-like lamin
of growth; ears unequal, marked with radiating ridges crossed by fine lines of growth.

This very beautiful species closely resembles the P. transversus of Devonshire, but is distinguished by its
smaller size, and the length considerably exceeding the width, the reverse of the proportions in the Devo-

96 SYNOPSIS OF THE CHARACTERS OF THE

nian species; the ears are also different; some of the finer strix are frequently flexuous. Length eight lines,
width seven and a half lines.

PrctTen LEIoTIs. M‘Coy. (Pl. XV. fig. 21).

Sp. Ch.—Longitudinally obovate, subtrigonal, flat; ears’small, nearly equal, pointed, smooth; body of the
shell radiated with about thirty-five smooth, sharp, slender, equal ridges; intervening spaces flat, about five
times the width of the ridges; slightly wrinkled transversely.

This beautiful shell resembles most closely the P. micropterus, M‘Coy, from which it is distinguished, as
from most others of the radiated species, by its smooth ears. Length ten lines, width nine and a half lines.

Prcten macrotis. M‘Coy. (Pl. XVI. fig. 13).

Sp. Ch.—Orbicular, depressed; slightly convex; ears unequal; anterior ear pointed, with strong, scaly
strie parallel to the margin; posterior ear very long, acute, with fine, radiating ridges, crossed by delicate lines
parallel to the margin, separated from the body of the shell by a steeply inclined space; surface of the shell,
with about forty-nine fine, radiating, flattened ribs, rather irregular in some parts of the shell.

This pretty species closely resembles the Pecten tabulatus, M‘Coy, but is distinguished by its more orbi-
cular form, longer, and longitudinally striated posterior ear, the more convex body of the shell, and, finally, by
the much greater number of its radiating ribs. Length five lines, width six lines.

PrecTen mecatotis. M‘Coy. (Pl. XIV. fig. 7).

Sp. Ch.—Lengthened, ovate; ears unequal, right ear very large, faleate; surface with about twenty-three
narrow, radiating ribs, intervening spaces striated across; large ear with very sharp, prominent, curved striz.

In this species the radiating ribs are small, rounded, and rather distant, one-half only reach the beak,
the other half terminate at about a fourth the length of the shell from the beak; the transverse striz are faint,
and rather irregular, strongest near the beak; the large ear is marked with numerous, sharp, scale-like striz.

PECTEN MELEAGRINOIDES. M‘Coy. (Pl. XVI fig. 3).

Sp. Ch.—Truncato-orbicular, convex; ears nearly equal, flattened, slightly pointed, not distinctly separated
from the body of the shell ; surface radiated with strong, rounded ridges, alternately larger and smaller ; the
interstitial spaces are about equal to the ridges in breadth, concave; surface marked with obsolete, concentric,
wrinkles.

This resembles the tuberculated valve of P. fallax, M‘Coy, in shape, but is distinguished by its smoother
ribs, and much wider and smoother interstitial spaces; the ears also are very different in form, resembling those
of a Meleagrina. Length ten lines, width eleven lines.

PrcTen microprerus. M‘Coy. (Pl. XV. fig. 12).

Sp. Ch.—Longitudinally ovate, slightly oblique, depressed; ears very small, anterior one rectangular,
posterior one-third longer, acute, having a straight, flat space between it and the body of the shell; with the
exception of the straight portion between the body of the shell and the posterior ear, the entire surface is ra-
diated with fine sharp ridges, distant about four times their diameter apart, intervening spaces smooth, with
obsolete, irregular, transverse wrinkles.

This species is remarkable for the small size and singular form of its ears, besides which, it is easily known
from the other ancient species, by its very distant, sharp, slender, radiating ridges. Length nine lines, width
ten lines.

CARBONIFEROUS FOSSILS OF IRELAND. 97

Precren munpus. M‘Coy. (PI. XVIL fig. 5).

Sp. Ch.—Ovate, convex; ears large, slightly pointed, equal, without radiating ridges, closely striated,
parallel to the margin; surface with distant, very fine, radiating ridges, alternately larger and smaller, decus-
sated by numerous, fine, concentric wrinkles.

In this species the radiating strie are remarkably slender, and three or four times their diameter apart ;
the ears are perfectly equal in size and shape, transversely striated; the concentric strie of the body of
the shell are fine, sharp, and about the same distance apart as the longitudinal ones, but rather regular.
Length four and a half lines, width four lines.

Pecten Murcuisonr. M‘Coy. (Pl. XVIII fig. 3).

Sp. Ch.—Shell longitudinally ovate; surface radiated with about twenty thick, nodular, ribs, alternating
with an equal number of smaller ones, the intervening spaces flat, smooth; ears large, equal, square, with three
or four ribs.

This elegant species is marked by about eighteen or twenty large, distant, radiating ridges, which, in
some lights, appear slightly tubercular; between these are an equal number of small ribs, the spaces between
which are perfectly even and smooth; the ears large and square, equal, smooth, with a few radiating, round
ribs, four on one side, and two on the other ; crossed on one ear by two ridges equalling the others in thickness, but
running parallel with the lateral margin; at each intersection of the ribs a large tubercle is formed. Length
one inch and a half, breadth one inch and a quarter.

PECTEN orBicuLaTus. J‘Coy. (Pl. XIV. fig. 8).

Sp. Ch.—Orbicular, very convex, smooth; ears acute, nearly equal, marked with radiating ribs.
This curious species is closely allied to the P. gibbosus, M‘Coy, but is at once distinguished by the form
of the ears, and their being marked with radiating striz. Length five lines, width six lines.

Pecren ovatus. MM‘Coy. (Pl. XIV. fig. 11).

Sp. Ch.—Ovate, flat, ears large, square; surface with about seventeen equal, distant, tuberculated ribs, the
spaces between which are sharply striated transversely.

This species has a more regular ovate form than any other with which I am acquainted; the ears extend
very nearly the width of the shell, and are radiatingly ribbed; the radiating ribs on the surface are regularly
tuberculated, and of equal size, although I have occasionally seen, as in the magnified figure, a very slender,
regular rib, tuberculated like the rest, extending up a short way from the margin; the intervening spaces are
delicately, but sharply striated across. Length eight lines, width seven lines.

Prcten pera. M‘Coy. (PI. XV. fig. 19).

Sp. Ch.—Ovate, slightly convex, front broad; ears large, unequal, anterior one rectangular, posterior larger,
pointed; surface radiated with very numerous, close, fine striae, alternately larger and smaller, crossed near the
margin by sharp, concentric lines; ears with about ten or twelve sharp, radiating striae, similar to those of the
body, and crossed by very delicate striz.

From the width, and slight convexity of the front, the outline resembles a bag or satchel. I am not sure
whether the radiating strie are spinose; in some lights they seem to be so, but the character is doubtful.
Length ten lines, width one inch.

2

98 SYNOPSIS OF THE CHARACTERS OF THE

Prcten PLAnicostatus. M‘Coy. (Pl. XIV. fig. 6).

Sp. Ch.—Obliquely obovate, slightly convex; ears short, square, unequal, smooth; surface with very
broad, irregular, smooth, flattened, radiating ribs, from the beak.

T have much doubt whether this shell really belongs to the genus Pecten—it is at least an aberrant type,
and if placed in this genus it leads to Lima, and if placed in Lima, it leads back to the present genus. The
hinge-line is oblique, the ears short, smooth, and slightly unequal; the surface of the shell is marked with
very broad, smooth ribs, much flattened, and dividing irregularly as they approach the margin, where they are
about twenty in number. Length one inch three lines, width one inch four lines.

Precren PLANocLATHRATUS. M'Coy. (Pl. XVI fig. 2).

Sp. Ch.—Longitudinally ovate, convex, reticulated with numerous, equal, longitudimal, and concentric,
broad, flattened ridges.

This species appears to be exceedingly rare, only one specimen being as yet known, and even that one is
imperfect as to the ears; the species is, however, easily known from any other by the flatness of the ridges.
Length ten lines, width nine lines.

PrcTEeN PLICATUS. Sow.

Pecten plicatus. Sow. Min. Con.

Sp. Ch.—Nearly orbicular, oblique, depressed; ears large, unequal, surface covered with fine, smooth,
flattened, irregular, radiating strie.
This species is closely allied to the P. papyraceus, but has much smaller ears, and coarser striz.

PEcTEN PoLtytTricuus. Phil.
Pecten polytrichus. Phil. Pal. Foss.

Sp. Ch.—Transversely elliptical, twice as wide as long; surface radiated with deep, sharp sulci, between
which are from six to nine finer radiating strie.

The character of the striation of this species resembles that of the Orthis interstrialis. I have never seen
specimens shewing the ears.

PEcTEN quinquetineATus. M‘Coy. (Pl. XVII. fig. 6).

Sp. Ch.—Longitudinally oval, nearly flat ; surface slightly irregular, marked with about thirty-five narrow,
uneven, radiating ridges, each pair having usually between them five smaller, radiating strie, the middle one
of which is largest, interstitial spaces flat; (ears unknown).

This fine shell at once strikes the eye, from its great size and regularly oval contour; the principal radiat-
ing ridges are strong and direct, but narrow; the intervening striz are almost invariably five, but in one or two
instances near the sides there are only three ; of these the middle or odd one is always larger than the others.
I have not seen the ears of this species. Length four inches two lines, width four inches.

Prcren rucuLosus. M‘Coy. (Pl. XVII fig. 7).

Sp. Ch.—Orbicular, slightly convex; ears distinct, nearly equal, anterior rounded, deeply divided from
the body of the shell, marked with four distant, radiating ridges; posterior slightly pointed, marked with three
or four rounded, radiating ribs; body of the shell with numerous close-set, radiating strie, alternately larger
and smaller, slightly nodular or roughened. :

This species, has little to attract attention, either in its form or markings, the distinct, radiating ridges on

CARBONIFEROUS FOSSILS OF IRELAND. 99

the ears, however, seem to fix it on the memory; the radiating ridges of the body are but slightly roughened
by an obscure nodulation, the spaces between them are slightly concave and smooth. Length ten lines, width
eleven lines.

Pecten sctrrotis. M‘Coy. (Pl. XVI. fig. 4).

Sp. Ch.—Longitudinally ovate, depressed, ears unequal ; surface with numerous longitudinal, rough ribs,
alternately larger and smaller; pointed ear, with obtuse stria parallel to the margin, and irregularly tuber-
culated.

Although the only specimen I know of this shell is imperfect, yet it is not likely to be confounded with any
other of the genus; it comes nearer to the P. Murchisoni, M‘Coy, than perhaps any other species, but has nearly
three times the number of ribs, and differently formed ears. The radiating ribs are narrow, rounded, and closely set
with small, erect scales; the spaces between them are deep, concave, and smooth ; there are about thirty of the
principal ribs, and an equal number of intervening shorter and thinner ones; the pointed ear, which is the only
one preserved in the specimen, has, near the base, numerous smooth, obtuse striae, the remainer of it being co-
vered with rough, irregular tubercles. The specimen is too imperfect to give the measurements correctly.

Pectren Sepcwicxi. Jd‘Coy. (Pl. XIV. fig. 4).

Sp. Ch.—Longitudinally ovate, convex; ears acute, surface smooth, with about ten broad, triangular con-
centric ridges; the ears are ridged parallel with the margin.

This singular species is concentrically marked with broad, triangular ribs, somewhat like those of Posido-
nia Becheri; the surface is otherwise perfectly smooth. I have dedicated this species to Professor Sedgwick,
to whose zeal we are indebted for the unique specimen figured on the plate.

Prcten secrecatus. M‘Coy. (Pl. XVII. fig. 3).

Sp. Ch.—Longitudinally ovate, slightly convex; ears unequal, one falcate, the other rounded; surface ra-
diated with very distant, narrow ridges, every fifth one twice the size of the others, alternately larger and
smaller; ears also radiated with similar, very distant ribs; interstitial spaces broad, flat, smooth.

This singular species is easily recognized by the great distance which the narrow, radiating ridges are
asunder, and the flat, smooth spaces between them; they are about a line apart in full-grown shells, and about
the thickness of a fine thread. The specimens are all imperfect; one of them, however, is one and a half
inches long.

PECTEN SEMIcIRCULARIS. M‘Coy. (Pl. XVII. fig. 10).

Sp. Ch.—Shell nearly flat, wider than long, front margin semicircular; anterior ear small, square at the
extremity, with three close, round, radiating ridges, crossed by sharp strie, parallel to the margin; surface of
the shell closely set with very fine, numerous, equal, radiating ridges, increasing in number towards the margin ;
intervening spaces flat, transversely striated.

This fine species is so much depressed as to appear nearly flat; the radiating ridges are smooth, very thin,
and numerous, new ones being continually added towards the margin; they are more than their own diameter
apart. Length two inches two lines, width three inches.

PECTEN SEMISTRIATUS. M‘Coy. (Pl. XVII fig. 9).

Sp. Ch.—Orbicular, convex, ears unequal; surface smooth, with the exception of a broad border round
the margin, which is marked with radiating striz, forming between them broad, unequal ribs, very slightly
convex.

100 SYNOPSIS OF THE CHARACTERS OF THE

This curious little species resembles the recent P. obsoletus in having the margin only marked with ra-
diating ribs or striz, which disappearing at about half the length of the shell from the beak, leave all the middle
of the shell and the region of the beaks perfectly smooth. Length eight lines, width three and a half lines.

Pecren serratus. M‘Coy. (Pl. XVIL fig. 8).

Sp. Ch.—Longitudinally ovate, depressed; ears very large, unequal; surface with about thirty narrow,
equal, radiating ribs, closely set with pointed scales; posterior ear pointed, with one or two longitudinal undula-
tions of the shell; anterior ear rounded, deeply divided from the body of the shell, with four or five rounded,
longitudinal ridges, crossed by erect, waving, scaly lines of growth.

This elegant species is perfectly unlike any other with which Iam acquainted; the spaces between the
numerous serrated ribs are smooth. Length six lines, width six lines.

Precren smuprex. Phil.
Pecten simplex. Phil. Geol. York.—Avicula simplex. Koninck. Fos. Bel.

Sp. Ch.—Obliquely ovate ; width two-thirds the length; left valve gibbous, right valve nearly flat; pos-
terior side steeply truncated; beaks prominent; hinge-line oblique, less than the width of the shell; ears very
small, equal, nearly square ; surface marked with strong, obtuse, radiating ridges ; intervening spaces transversely
striated.

This pretty little species cannot with propriety be included either in Pecten or Avicula, and a new group
is much wanting to include it and a number of other fossils.

Pecren Sowrersu. M‘Coy. (Pl. XIV. fig. 1).

Sp. Ch.—Elliptical, convex in the middle; ears small, equal, acute, conate ; surface concentrically striated.

This very beautiful species is distinguished from all the others of the carboniferous limestone by the form
of its ears, which are equal, acute, and conate, being considerably elevated above the beak of the shell, as we
see in some Oolitic species; the surface is concentrically striated. Length one inch one line, width one inch.

Prcrten spinutosus. M‘Coy. (Pl. XVII fig. 1).

Sp. Ch.—Longitudinally ovate, convex; ears large, nearly equal; anterior rounded, posterior pointed ;
body of the shell radiated with about twenty-six sharp, regularly spinose ridges, between each pair of which
intervenes one much finer rib, also regularly set with spines at the same distances as those on the larger ridges;
ears with close, radiating ridges, crossed by sharp, imbricating striz.

The spines are placed at such regular distances on the ribs of this little species, that they seem to form
concentric, as well as longitudinal rows; they are cylindrical, solid, and placed rather far apart; the ears are
remarkably large, nearly equal, and square. Length three and a half lines, width three and a half lines.

Pecten Tasutatus. M‘Coy. (Pl. XVI. fig. 12).

Sp. Ch.—Lengthened, ovate, flat; ears nearly equal; posterior ear rounded, with two or three longitudinal
folds, crossed by very strong, scaly striz, parallel to the margin ; anterior ear acute, faleate, with fine striz pa-
rallel to the curved margin. This ear is deeply divided from the body of the shell by a steep space; surface of
the shell with about fifteen flat ribs, separated by very narrow, deep sulci; each rib branches as it reaches the
margin.

This little species is remarkable for the perfect flatness of the body of its shell, which is, nevertheless, of
considerable depth, being much elevated above the plane of the ears, from which it is consequently separated by
avery steep plane. Length about six lines, width six hnes.

CARBONIFEROUS FOSSILS OF IRELAND. 101

PECTEN TRANSVERSUS. Sow.

Pecten transversus. Sov. Geol. Trans.—Pecten transversus. Phil. Pal. Foss.

Sp. Ch.—Transversely oval, slightly convex; ears moderate, nearly equal, acute; surface with strong
radiating ridges, disposed in about twenty-six fasciculi of three each, each bundle being distinctly separated
from the adjoining ones; entire surface marked with fine, sharp, concentric striz.

This species resembles the P. Knockonniensis, M‘Coy, which see: the specimens which have occurred
are very imperfect.

Prcren Tripartitus. M‘Coy. (Pl. XVI. fig. 8).
Sp. Ch.—Longitudinately ovate, longer than wide, slightly convex; ears very unequal, one small, square,
the other very large, rounded; sides finely and sharply striated longitudinally ; middle of the shell smooth.
This species has its surface divided longitudinally into three portions, the two outer of which are delicately
striated, and the middle one smooth; this is much more distinct in some specimens than in others, but is always

perceptible; the ears are very unequal, the smal! one smooth, the larger with coarse, radiating strie. Length
four lines, width three lines.

PrecTen unpuLatus. M‘Coy. (Pl. XVII fig. 12).

Sp. Ch.—Elongate, ovate ; ears unequal, posterior one small, pointed, anterior large, rounded, deeply divided
from the body of the shell; surface with numerous, equal, fine, concentric stria, decussated by radiating strie
similar to the transverse ones in shape and size, but rather farther apart; three or four short, round plaits in the
posterior side-margin.

This species is rendered very remarkable by the short, obtuse folds or plaits in the posterior margin, and
I have found the character constant in six or seven specimens which came to hand of the species, they appear

very characteristic; the whole surface is beautifully reticulated, with slightly flattened, delicate strix. Length
ten lines, width nine lines.

PEcCTEN vARIABILIS. MM‘Coy. (Pl. XVI fig. 7).

Sp. Ch.—Shell smooth; ears unequal; anterior ear square at its extremity, narrow; posterior ear rectan-
gular, undefined; form varying from longitudinally ovate to orbicular, and from slightly convex to globose.

The normal character of this very variable species appears to be a longitudinally ovate form, the length,
however, but little exceeding the breadth, moderately convex, and perfectly smooth; but among the countless
varieties some are nearly flat, others almost hemispherical; some shew a plication of the surface, longitudinal,
oblique, or concentric, and some extreme varieties are even wrinkled or undulated concentrically; these are,
however, obviously the abnormal conditions; the parts about the beak or the ears are not liable to variation.
Lengh eleven lines, width nine lines.

Monotis. Bronn.
Gen. Ch.—Suborbicular, inequivalve; usually rounded anteriorly ; auriculated posteriorly; ears un-
defined.

Those shells differ from Pecten in having their ears usually undefined, and very frequently no ear on the
anterior side, whence their name.

Monotis mquatis. M‘Coy. (Pl XV. fig. 1).

Sp. Ch.—Suborbicular, length and width equal; hinge-line less than the width of the shell; right valve
convex, posterior ear pointed, anterior ear small, rounded; left valve flattened; body of the shell radiated with

2C

102 SYNOPSIS OF THE CHARACTERS OF THE

about twenty-six unequal, rounded ridges; ears radiated with three or four similar ridges; the ears, and some-
times the margin of the valves, are sharply striated concentrically.

This curious little shell resembles the M. decussata of the Oolite in shape, having a distinct, but small ear
on the anterior side. It occurs in great abundance in company with the P. simplex, Phil., which it much re-
sembles, but which is easily known from the present shell by its smooth, equal ears, finer strie, and lengthened,
oblique form. Length three lines, width three lines.

BRACHIOPODA.

Before entering on the Brachiopoda I shall give a brief outline of what has been done by the principal
writers on the subject.

Cuvier included in his Brachiopoda only the genera Lingula, Terebratula, Spirifer, Thecidea, Orbicula,
and Crania.

Lamarck removed Crania from the Brachiopoda to his family Rudistes, in which he also placed Calceola
and Diseina; he included only in the Brachiopoda the genera Orbicula, Terebratula, and Lingula.

De Blainville forms his order Palliobranchiata of the genera Lingula, Terebratula, Strophomena, Dian-
chora, Thecidea, Plagiostoma, Podopsis, Orbicula, and Crania. This author, it will be observed, admits the
genus Strophomena (Productus), but also arranges with them Dianchora, Podopsis, and Plagiostoma, genera
which almost every other author agrees to have little or no affinity with them.

Deshayes recommends the suppression of the genus Spirifer, considermg, with many others, that the spiral ap-
pendages are the spiral arms of the animal, common to all the Brachiopoda; hence he believed that genus not to
possess any peculiar generic character, and therefore places all the Spirifers either in the genus Terebratula
or Producta, according to whether the foramen in the beak of the large valve be distinctly visible or otherwise.
Leaving out of consideration what appears to be the primary error in this view, namely, the considering the
spiral appendages of Spirifer as the spiral arms of the animal, a great source of inconvenience in this arrange-
ment is, that nearly allied species, and sometimes even two specimens of the same species, must be separated
into two distinct genera.

Von Buch, in his Memoir, “ Uber die Terebrateln” (1834), produced the most remarkable and valuable
arrangement of this tribe which we possess. His method is a dichotomous one, somewhat resembling Dr. Fle-
ming’s system. He first divides the Brachiopoda into those which are attached by the margin, and those at-
tached by the lower side of the shell. The first group he then divides into those which have one valve perfo-
rated, and those having neither valve perforated. The former he afterwards subdivides into those which have
the perforation separated by a deltideum from the hinge-line, including, under the name of Terebratula, the
genera Atrypa, Strigocephalus, Uncites, Pentamerus, and Megas*, and those which have a triangular foramen,
the base of which rests on the hinge-line, including, under the name of Delthyris, the genera Spirifer, Orthis,
Cyrtia, and Gypidea. Those having neither valve perforated, he separates into such as have a large cardinal
area, including only Calceola; and such as have no cardinal area, being Leptena (Producta, Strophomena).
His second great division, those attached by the lower side, is divided into that having the lower valve pierced
for attachment, containing Orbicula, and secondly that having the lower valve entire, and attached byits whole
face, including Crania.

“Professor Phillips translating this table in his “ Palaeozoic Fossils,” places Orthis in this division instead of
the next.

CARBONIFEROUS FOSSILS OF IRELAND. 103

Vv

Professor Phillips (Paleozoic Fossils of Devon) has proposed, I believe, the latest important classification of
the group before us. His arrangement resembles that of Von Buch. I give it in his own words:

“ BRACHIOPODA.

Valves free, attachment by exserted muscle.

Valves equal Cd eate es fe 3 oe i ety bene Bl Lcagotie

Valves unequal, larger valve imperforate (Athy yrid@).

No cardinal area Producta.

A cardinal area. - Calceola.

Larger valve perforated in or a date ihe haa

Perforation reaching to the hinge-line . . . 7 ae CDelthyredey,
Cardinal area more or less common to both Valea! be eb. aces AOTC
Cardinal area confined to the larger valve.

Internal plates of larger valve separate . . . Spirifera.
Internal plates of ihe. larger valve united on the eel he of the
shell.

Plates narrow CD iO ao 6 & 6 fs 5 RNC MIGIIS.

Plates very broad .

ah ye ob eh) ti Gee enieamentss
Cardinal area obsolete ; beak incur fa over a minute perforation,
which is often obtect, or merely serves to receive the beak of
the smaller valve a oisee: Cleiothyris.
Perforation not reaching to the hinge-line. . . . - . . . . « (Cyelothyris).
Beak truncate, perforate . Pole 6 OB the oO ee a Jo mdoTeS
Beak acute, the perforation below it Hypothyris.”

None of the Brachiopoda have a distinct head, eyes, tongue, or any other external organs of sense. They
differ from all the other bivalves, in their shells being symmetrical, one side perfectly resembling the other, and
each shell might almost be considered as containing two individuals, socompletely does this symmetricity extend to
the animal: thus, they have two hearts, one on each side; two circulatory systems, which only meet in the centre,
where they supply the organs of nutrition; the stomach and intestinal canal occupy the centre of the shell, and
are remarkably small; the muscles are disposed in an equally symmetrical manner; the foot of other bivalves is
replaced in those animals by two long, spirally-rolled, tubular arms; the use of these singular organs has been
very variously stated. Fischer, of Moscow, took them for the organs of digestion. Pallas and De Blainville
considered the fringes with which those arms are provided to be the gills of the animal; Cuvier opposed this
opinion, from having found the gills ofthe genus Lingula on the inner side of the mantle. Miiller (Naturforschen),
from an attentive observation of their habits was led to the conclusion that they served the animal for securing
its prey; this is now known to be their true function. They are protruded from the shell by being inflated, or
forcibly filled with fluid; when this is effected, they unroll themselves; the largest, or basal turn, by iereasing
in diameter, forees open the valves, which have no cartilage, or other contrivance, except this, to keep them
open; and then the delicate extremities, being protruded beyond the edge of the shell, fall into the sea, where
they hang until the agitation of the waters bring some little Molluse within their grasp, when the cause which
protruded them being removed, they coil themselves round their prey, and by rapidly retracting to their ori-
ginal position, bring the food to the mouth of the animal, which is situated in the centre between them; the
arms retract, from the elasticity of the cartilaginous tubes of which they are formed, not by any muscular action.
The primary divisions of the tribe appear to consist of the following families: 1. Delthyride, or Spirifers;
2. the Athyride, or Productas; 3. the Orbiculide, the Orbiculas; 4. the Terebratulide, or true Terebratulas ;
and 5. the Pentameride, or chambered Brachiopods.

It will be seen that I have differed from the preceding writers by excluding the genus Lingula from the true

104 SYNOPSIS OF THE CHARACTERS OF THE

Brachiopoda, to which, in my opinion, it has little immediate affinity, both the animal and the shell differing
in the most important characters; thus the Brachiopoda have two hearts, Lingula, like the ordinary bivalves,
has but one; all the Brachiopoda are inequivalve, Lingula equivalve: the Brachiopoda (when attached) have
one valve perforated for the passage of the muscle of attachment, in Lingula the muscle of attachment passes
between the valves, neither of them being perforated; in Lingula, the gills are attached to the mantle, nearly as
in ordinary bivalves, while the true Brachiopoda have no gills at all, the surface of the mantle being covered
with vibratile ciliz which serve the same purpose; and many other points of structure, not only in the shell but
in the animal, induced me to consider the relation of this genus to the Brachiopoda as less strong than it has
been usually considered, and to view it rather as a connecting link between the Brachiopoda and the Dithyra.

OrpicuLta. Lam.

Gen. Ch.—Depresso-conical, suborbicular; ventral valve flat, perforated by an oblong fissure for the byssus
of attachment; four muscular impressions in each valve.

OrpicuLa NniTipA. Phil.
Orbicula nitida. Phd. Geol. York.—Orbicula nitida. Portk. Geol. Rep.—Orbicula cincta. Porth. Geol. Rep.

Sp. Ch.—Longitudinally oval, slightly narrowed in front, apex about one-fifth the length from the ante-
rior end; upper valve convex, lower valve flat, perforated ; surface with concentric, imbricating striz, and very
fine, radiating lines.

I believe the O. cincta, Portk., may be considered a variety of this species; the radiating striz are very
minute. Length seven lines, width six lines.

ORBICULA QUADRATA. M‘Coy. (Pl. XX. fig. 1).

Sp. Ch—Subquadrate, very much depressed, length and breadth equal; beak small, inflexed, one-third
the length of the shell from the margin; surface rough, with concentric, scale-lke lines of growth.

This species is at once distinguished from the O. nitida, Phil., by its greatly depressed, quadrate form, and
its strongly imbricated surface; the specimen figured was found on a Turbinolia. Length five lines, width the
same, height half a line.

OrpicuLa TRIGONALIS. M‘Coy. (Pl. XX. fig. 2).

Sp. Ch.—Conical, obovate, trigonal; anterior end narrow, rounded, posterior subtruncate; surface uregu-
lar, marked with close, rounded, radiating ridges from the beak, which is small, deflexed, and little more than
one-fourth the length from the anterior margin.

This is the only species of Orbicula in the older rocks which is marked with radiating ridges; the form
is somewhat irregularly conic, depressed, closely set with round, slightly irregular, radiating ridges. Length
four and a half lines, width three lines.

Famiry ATHYRID/.

The Athyride@ or Productas are distinguished as a family from all the other Brachiopods, by being defen-
sively armed with large, strong spines.

That the Athyride immediately follow the Delthyride or Spirifers is, 1 think, evident, from the close
connexion which exists between the genus Orthis, among the Spirifers, and Leptagonia, M‘Coy, in the pre-
sent family, so nearly resembling each other that it is sometimes difficult to determine to which of them a spe-
cies may belong; while the tunion on the other side to the Orbiculide is evident from the similarity of their

CARBONIFEROUS FOSSILS OF IRELAND. 105

internal structure. Among the earliest scientific notices of these shells were those by the celebrated Mr. Martin,
whose admirable figures of the more abundant species are, perhaps, the best we have. He formed of them one
of his divisions of Anomites, under which name most of the fossil Brachiopoda were then described. Mr. Sow-
erby subsequently gave this division the name Productus; this term is now usually laid aside in favour of Dal-
man’s name Leptena. I have, however, retained the former appellation for the typical genus in the following
pages. I have also retained Dalman’s name, but use it in a restricted sense, confining it to those flat, scale-like,
species analogous to the Leptena lata, and which abound in rocks of the Silurian range; while those very ine-
quivalve, large, hemispherical species, to which I now? retain the generic name Producta, are quite unknown in
the Silurian rocks, but abound in the carboniferous limestone, where the other form is comparatively rare. I
have considered Leptena, as here restricted, to form a sub-genus of Orthis, rather than as a part of the family
Athyride. As the internal structure of the Athyride@ is even less known than that of the Spirifers, I shall,
when treating of each genus, lay before the reader what I have been able to discover of it.

Crania. Retz.

Gen. Ch.—Subquadrate ; upper valve conical; apex nearly central; lower valve thick, entire, attached by
its whole inferior face; four muscular impressions in each valve.

Cranta vesicuLosa. M‘Coy. (Pl. XX. fig. 3).

Sp. Ch.—Ovato-orbicular, wider than long; hinge-line slightly truncated ; apex one-third the length of
the shell from the hinge-line, before’ and on each side of it are placed two obscure tubercles, so situated that,
with the beak, they form an equilateral triangle; surface obscurely undulated concentrically.

This is the only species of Crania which has come under my notice in the Ivish mountain limestone. It
is nearly orbicular, or a very little wider than long; the hinge-margin is obscurely truncated (distinguishing
it at once from Orbicula), the surface is rather irregular, slightly imbricated concentrically. This species is
allied to the C. prisca, Hen., but that species is longer than wide, while in this the proportion is reversed ; they
also differ in many minor points. Length eight lines, width ten lines, height six lines.

Catcrota. Lam.

Gen. Ch.—Triangular, very inequivalve; cardinal area very broad, flat, triangular, reticulated; dorsal
valve semiconic, beak pointed ; ventral valve flat, semicircular; hinge-line plicated.

CALCEOLA SANDALINA. Lam.

Sp. Ch.—Dorsal valve pyramidal, smooth; beak slightly, or not at all incurved; cardinal area flat, triangu-
lar, marked with decussating strie; ventral valve flat, semicircular; hinge-line sulcated.

Propucta. Sow. (Restricted).

Gen. Ch.—Shell hemispherical, eared; dorsal valve very convex, ventral valve concave ; hinge-line long,
equalling or exceeding the width of the shell, compressed; no cardinal area or foramen.

The species of this old and extremely natural genus are all very inequivalve, the dorsal valve being very
convex, usually with a mesial hollow, and striated longitudinally from the beaks. The ventral valve is con-
cave, generally with a mesial elevation, corresponding to the depression in the dorsal valve. The position of the
muscular impressions differs essentially from that of the Spirifers; they are also considerably larger than those
of that genus. The two pair of principal adductors arise one pair on each side of the beak of the dorsal valve,
forming a large square cicatrix; these form elevations in the cast. The principal pair of adductors of the ventral

* The above was written three years ago.

2D

106 SYNOPSIS OF THE CHARACTERS OF THE

valve form two large, irregular, oval cicatrices in the ventral valve, situated one on each side, about midway
between the central septum and the lateral margin of the shell, and about their own length distant from the
anterior margin (see fig. 9, the ventral valve of the Producta pustulosa, BB); EE (fig. 9) shews the origin
of the second pair of adductor muscles, forming small, pear-shaped cicatrices, close to the central septum, the
lower, dilated portion curving outwards. The ventral valve is connected to the dorsal, by a kind of cardinal
tooth, usually notched (see fig. 10, B), similar to that of Thecidea. There is in Fig. 9.

the centre of the ventral valve of all the species, a long, prominent, shelly, septum
arising from the cardinal tooth, and extending to within a short distance of the
anterior margin; it increases in prominence towards its anterior end, where it is
abruptly truncated or rounded according to the species; it is in some measure ana-
logous to the central septum, in the dorsal valve of the Spirifers. The beautiful
markings, represented fig. A A, may be viewed as a modification of the spiral appen-
dages of Spirifer ; they are in fact the support for the arms of the animal, but in-
stead of their extremities being free, and projecting into the cavity of the shell, as
in Terebratula or Spirifer, it is fixed along its whole length to the surface of the
ventral valve, as we see in 7'hecidea and Crania; the reason of this difference appears
to be that Spirifer and Terebratula, having convex ventral valves, and being at-
tached so as to hang by the beak, their arms are so placed, that the bases of the cones which they form, when
retracted, become parallel, and their extremities, when unrolled, extend in the direction of the anterior margin
of the valves, the supports in that case extending themselves into the centre of the cavity of the shell; but in
these Brachiopods, as Crania, Thecidea, Orbicula, &c., which have the ventral valve flat, the arms are coiled
so that their bases rest on its surface, both on the same plane; the supports, therefore, are always fixed, in their
entire length, to the internal face of the ventral valve, and project but slightly from it. That the arms of the
Product were also placed in the same manner, appears evident from the accordance pointed out in the form
and mode of attachment of the appendages; and if so, we would have an important anatomical fact to justify
the allocation of the Producte (Athyride), near Orbicula.

PRopUCTA ACULEATA. Mart. sp.

Anomites aculeatus. Martin, Pet. Derb.—Productus aculeatus. Sow. Min. Con.

Sp. Ch.—Rounded, very gibbous; beaks large, tumid; front slightly indented; smooth; dorsal valve with
irregular, adpressed spines; ventral valve without spines.

This species is chiefly remarkable for the curious position of its spines, which have their points directed
towards the beak, appearing, as it were, to force themselves up through the surface of the dorsal valve; their
bases are large, few, and irregularly placed; the ventral valve is very concave, and has no spines; excepting the
spines on the dorsal valve, the surface is perfectly smooth; the hinge-line is exceedingly short. Length five
lines, width six lines.

PRODUCTA ANTIQUATA. Sow.

Anomites semireticulatus. Martin, Pet. Derb.—Productus antiquatus. Sow. Min. Con.—Productus lobatus. Deshayes.

Sp. Ch.—Subquadrate ; surface with coarse, rough, longitudinal strie; rostral portion of the shell trian-
gular, entirely covered with concentric undulations, which become large and spinous towards the sides; front
of old shells produced subcylindrical, with parallel sides, which are without striz, but have numerous, very long,
curved spines; mesial hollow wide; both valves nearly alike; width of the hinge-line equal to the length of the
shell.

This is the most common species of the genus; Martin’s figure, above referred to, obviously represents a
young shell of this species, having a flattened, triangular figure, and the entire surface reticulated by the con-
centric wrinkles. The same portion has been.figured by Sowerby, in the Mineral Conchology, under the name

CARBONIFEROUS FOSSILS OF IRELAND. 107

Productus antiquatus, and by M. Deshayes, under that of Producta lobata, to which latter shell it only bears
the most remote resemblance. As yet I am not acquainted with a figure of the adult shell, such as it usually
occurs in our limestone. Professor Phillips’ figure represents a curious variety, a specimen similar to which I
have seen from the limestone of Cornacarrow, near Enniskillen, it is cylindrical, without mesial hollow, or large
concentric wrinkles, and with a considerable smooth space between each of the radiating strix ; altogether it has a
peculiar appearance, and may possibly be distinct. Length usually about three inches. Martin’s name should,
perhaps, be adopted for the species, as having the priority, but Mr. Sowerby’s name is so well known, that I

have thought it better to retain it.

Propucta Aurira. Phil.
Professor Phillips proposes this name for the P. hemispherica and P. Scotica of Sowerby, united. I have
occasionally used the name for a few specimens which have occurred, resembling P. Scotica, but with very few

spines, and having the ears unusually long.

PRODUCTA CAPERATA. Sow. SP.

Leptena caperata. Sov. Geol. Trans.—Leptiena caperata. Phil. Pal. Fos.

Sp. Ch.—Hemispherical, very convex, no mesial hollow; concentrically wrinkled; surface with small,
very numerous, oblong, tubercles arranged in quincunx; ears transversely wrinkled.

This species differs from the Producta scabricula in being much more convex, and more nearly orbicular
in its outline; it has no trace of mesial furrow, the concentric wrinkles are stronger, and the tubercles smaller
and much more numerous than those of the Producta scabricula ; when well preserved, there are long, slender
spines on the hinge-line. Length one and a half inches, width two inches, depth ten lines.

PropuctTa comormeEs. Sow.

Productus comoides. Sow. Min. Con.

Sp. Ch—Semicireular, very gibbous, inflated; hinge-line equal to the width of the shell, cardinal area
wide, with nearly parallel sides; shell very thick; surface with very fine, waved, radiating striz.

I am not sure that I by any means understand this species: the very large shell which I have been in the
habit of considering as P. comoides, I have recently been inclined to consider as the adult state of Professor
Phillips’ O. papilionacea ; they agree perfectly, however, with Sowerby’s figure and definition of his P. co-
moides, with the exception, perhaps, of the cardinal area not having such parallel sides: on the other hand,
specimens of a shell given me by Lady Peschel present a cardinal area with truly parallel sides, a very thick
shell, and similar form, but it is very coarsely sulcated, and possesses a hinge distinct from either Producta or
Orthis. Professor Phillips and M. de Koninck have, I think, figured a distinct species under this name.

PropuctTa CoNCINNA. Sow.

Productus concinnus. Sow. Min. Con.—Producta concinna. Phil. Geol. York.

Sp. Ch.—Subcylindrical, very short, rounded, front evenly convex ; surface coarsely striated longitudinally,

concentrically wrinkled near the beak. Length and width equal.

This little species bears a great resemblance to the top, or rostral portion of the Producta Martini, it is,
however, much smaller, more rounded, and the surface more evenly formed; the top of the ventral valve fre-
quently has a distinct, nearly smooth margin, as in that species. Length seven lines, width six lines.

Propucta corrucata. M‘Coy. (Pl. XX. fig. 13).

Sp. Ch.—Hemispherical, the concavity of the ventral valve nearly equalling the convexity of the dorsal ;
radiating strie narrow, sharply defined, alternately larger and smaller; four or five large wrinkles on each side.

108 SYNOPSIS OF THE CHARACTERS OF THE

In general proportion this exactly resembles the Producta hemispherica, but the large, concentric wrinkles
are peculiar and very constant; the ventral valve is less concave than in that species, and even fragments might
be distinguished by the peculiar character of their striz ; these are thick, close together, and slightly rounded or
flattened in the Producta hemispherica, but are very sharp and distinct, alternately larger and smaller, and
having a small space between them, in the present species.

Propucta costeLtatTa. M‘Coy. (PI. XX. fig. 15).

Sp. Ch.—Semicylindrical, short, front flattened, sides compressed ; surface with strong, radiating ribs,
muricated by long cylindrical spines; a semicircular row of large spines on each side of the shell.

This species bears some likeness to the P. spinosa, but the radiating ribs are greatly stronger, and the front
is flattened; the present shell has also a semicircular row of large spines at each ear, and the spines of the whole
Fig. 10. surface are much larger, and more numerous, than in that shell. Its very short hinge-line, pa-

Tm_* rallel sides, and coarse muricated ribs distinguish it from the Producta setosa, Phil. Length

eight lines, width seven lines.

The internal structure (see fig. 10) is much more simple than of most of the Producte;
the supports (A 4) form but two lobes on each side of the septum, instead of the numerous
complex turns of the corresponding parts in the more typical species; the cardinal tooth of the
(i. ventral valve (8) is large, and distinctly notched; the muscular impressions (cc and DD) are
similar in shape and position to those of the other Producte; the central septum is particularly large.

Propucta Epretpurcensis. Phil.
Producta Edelburgensis. Phil. Geol. York.

Sp. Ch.—Semicircular, depressed; beak small; ears flattened; radiating strie thick, branching frequently
before they reach the margin.

This curious species is very like old individuals of Producta latissima, but is more depressed; the beak
is also much smaller, and the ears, which in Producta latissima are almost fusiform, are quite flat in the pre-
sent shell; the radiating striz of the Producta Edelburgensis have a peculiar appearance, from being thick and
entire, to a short distance from the beak, and then suddenly dividing into a great number of smaller ones, as
they approach the margin; these ribs are finely striated across, but usually without spines. Length one inch five
lines, width three inches six lines.

Propucta ELEGANS. MM‘Coy. (Pl. XVIII. fig. 13).

Sp. Ch.—Shell forming three-fourths of a circle, convex; nine or ten concentric sulci, the rostral edge of
the broad furrows between them, with two or three concentric rows of short, deep, undulating scratches, the
marginal edge with three or four concentric rows of punctures, set in quincunx; beak small; hinge-line straight.

This pretty little shell is related more to the young of P. fimbriata, Sow., than to any other of the genus;
it is, however, much more depressed; the beak is large and prominent in that shell, but very small in this; and,
finally, the ridges are greatly more numerous in the present species, and punctured on the marginal edge, in-
stead of on the rostral, as in that fossil. The ears of the P. elegans are much flattened, the ventral valve simi-
lar, but flatter. Length five lines, breadth six lines.

PRODUCTA FIMBRIATA. Sow.
Productus fimbriatus. Sow. Min. Con.—Producta fimbriata. Phil. Geol. York.

Sp. Ch.—Slightly elongate, rounded, very gibbous; about seven or eight broad, concentric ridges, each
fringed on its rostral edge with a row of lengthened, spine bases; no mesial furrow.

CARBONI¥YEROUS FOSSILS OF IRELAND. 109

This is an exceedingly variable shell, scarcely two specimens being found alike. Ihave taken as the type
of the species, however, those specimens which agree most nearly with Sowerby’s original figure and descrip-
tion. In these there are usually about eight transverse, smooth, ridges, about a line in width, the rostral mar-
gin being prominent, and bearing a row of narrow, lengthened, tubercles, which give the ridges an elegantly
fringed appearance ; the dorsal valve is very convex, and the beak large and tumid; the ventral valve is but
slightly concave, it has flat, concentric ridges, and numerous spinulose puncta. The varieties differ in the irre-
gularity of the spines, and the concentric ridges becoming almost obsolete. Length one inch one line, width

one inch.
PropucTAa FLEXISTRIA. JZ‘Coy. (PI. XX. fig. 16).

Sp. Ch.—Semicylindrical, short; front flattened; beak globose, rather depressed ; mesial furrow slight, or
none; surface coarsely striated longitudinally; five or six large, smooth furrows on the sides, curved nearly three-
fourths of a circle, encircling a small, concave, smooth space.

This shell is more nearly related to the Producta sulcata, than to any other of the genus; it is, however,
more finely, and less regularly striated, in addition to which the remarkably curved ribs on the sides distinguish
it from that, and every other species of the genus with which I am acquainted. The two valves are nearly si-
milar, the beak of the ventral one, however, being less globose than that of the dorsal, the front is square, and
the sides flattened, having, as before mentioned, a nearly circular, depressed, smooth space, near the extremity
of the hinge-line. Length one inch one line, width one inch two lines.

PRODUCTA FRAGARIA. Sow. Sp.

Leptena fragaria. Sow. Geol. Trans.—Leptena fragaria. Phil. Pal. Fos.

Sp. Ch.—Transversely oval, gibbous ; numerous large, spiniform tubercles, arranged nearly in quincunx
order, alternately connected by concentric wrinkles; no mesial furrow.

This species is by many authors considered to be a variety of the P. rugata, but differs constantly in being
nearly one-third wider in proportion to its length, beg more convex, and in having the spines much more
numerous and more regularly placed; the concentric rug are also smaller, more numerous, and more regular
than in that species. Length six lines, width eight lines; frequently twice this size.

PRODUCTA GIGANTEA. Sow.

Anomites giganteus. Martin, Pet. Derb.—Productus giganteus. Sow. Min. Con.

Sp. Ch.—Transversely oblong; beak very gibbous; sides dilated into large, rounded ears; surface with
large, slightly flexuous ribs, covered by coarse, waving strie, with small, nregular spines. Length two-thirds
the width.

This very large species is remarkable for having longitudinal ribs, as thick as a man’s little finger, on the
surface of the dorsal valve; they are somewhat undulating, and accompanied by numerous, nregular, rough,
flexuous striz. Width nine or ten inches.

Propucta GranuLosa. Phil.
Producta granulosa. Phil. Geol. York.

Sp. Ch.—Transversely oval, gibbous; hinge-line very short; sides rounded, flattened ; ventral valve slightly
concave; surface with numerous, crowded, minute tubercles; no mesial furrow.

This little shell is almost destitute of ears, the flattened sides of the shell hardly deserving that name;
the dorsal valve is very gibbous, particularly towards the beak; the tubercles which crowd the surface have no
particular order of position; they are very small and numerous; there is no mesial furrow in either valve.
Length eight lines, width nine lines.

2E

110 SYNOPSIS OF THE CHARACTERS OF THE

PRODUCTA HEMISPHERICA. Sow.
Producta aurita (pars.) Phil.

Sp. Ch.—Shell hemispherical ; ventral valve very concave; radiating strie close, obtuse, smooth, without
spines; hinge-line equal to the width of the shell.

In this species the ventral valve is almost as concave as the dorsal is convex, so that there results between
them an exceedingly small space for the animal; the ears are short, convex, rounded; the strie are equal, close,
and obtusely rounded; the P. personata, Sow., is probably the internal cast of this species. Size very variable,
leneth from one and a half to three inches.

Propucta INTERMEDIA. M‘Coy. (Pl. XX. fig. 4).

Sp. Ch.—Transversely elliptical; no dorsal furrow; gibbous near the beak; with about twelve narrow,
concentric sulci; the intermediate broad ridges are flattened, with three rows of small spmes, in quincunx;
deflexed, front broad, forming rectangular ears at the sides; very finely striated longitudinally.

This curious shell forms a connecting link between the genera Producta, Auct., and Leptagonia, M‘Coy,
the portion near the beak is a perfect Producta, and might be compared with the P. punctata, while the nearly
smooth, deflected front reminds us at once of Leptagonia. Length one inch eleven lines, width one inch six
lines; the flat, concentric ridges are about a line in width, but become narrower towards the beak.

PropuctTa INTERRUPTA. Sow. SP.
Leptzena interrupta. Sow. Geol. Trans.
Sp. Ch.—Semicircular, gibbous; hinge-line equal to the width of the shell; surface with about twelve
rounded, concentric wrinkles, crossed by strong, radiating strie from the beak.
The most peculiar character of this little species is the interruption of the longitudinal strie by the concen-
tric wrinkles, giving them a fringed appearance. Length seven lines, width eight lines.

Propucta LacintaTA. M‘Coy. (Pl. XX. fig. 12).

Sp. Ch.—Nearly semicircular, length one-sixth less than the width; hinge-line rather less than the width
of the shell; moderately convex; beak small, prominent; ten or twelve rounded, concentric wrinkles, fringed
on their marginal declivity with close, regular, lengthened spine bases.

This rare species bears some resemblance to the P. fimbriata, Sow., but the convex valve of the present
shell is nearly as flat as the small valve of the P. fimbriata; the general form is more transyerse, depressed,
and the beak is greatly smaller; the number of concentric ridges is greater, and they are more closely and re-
gularly fringed, with smaller spines, which latter are also set on the marginal, instead of the rostral edge of the
wrinkles. Length eleven lines; width one inch one line.

PRODUCTA LATISSIMA. Sow.

Productus latissimus. Sow. Min. Con.—Producta latissima. Phil. Geol. York.

Sp. Ch.—Hinge-line very wide; beak much curved, but not large or prominent; ears involute, not
distinguished from the body of the shell; very coarsely striated from the beak; spines numerous, very small.
Length one-third the width.

The margin curls inwards, so as to give a fusiform appearance to the Whole shell, when young, but with
age it becomes nearly hemispherical, the surface assumes a ridged appearance, and the striz, branch and become
finer, the whole shell resembling the P. gigantea, which it sometimes nearly equals in size; it is distinguished,
however, by its smaller, and much less prominent beak. The striz are very thick and distinct for about three-
fourths ofan inch from the beak, when they suddenly divide into a great number of smaller, flexuous ones, as

CARBONIFEROUS FOSSILS OF IRELAND. 111

in the Producta Edelburgensis. There are numerous small spines on the surface, but, when broken away, they
leave so small a mark, that they are frequently overlooked. Length one inch, width two and a quarter inches.
This is the usual size of specimens.
PropucTa LAXxIspIna. Phil.
Producta laxispina. Phil. Geol. York. and Pal. Fos.

Sp. Ch.—Hemispherical, hinge-line long, ears large; surface smooth, with greatly lengthened, obsolete,
tubercles, irrecularly placed.

This shell has much the appearance of the Producta spinosa, but the length of the hinge-line, and the
great size of the ears, at once distinguish it; its comparatively smooth surface distinguishes it from the other
allied species; the spmes are very remarkable, they are so much elongated as almost to assume the appearance
of ribs, they are not strongly marked. Length one inch, width one and a quarter inches.

Propucta LiraTA. Phil.
Producta lirata. Phil. Geol. York.
Sp. Ch.—Small, subcylindrical, very gibbous; beak large; hinge-line equal to the width of the shell; ears
small, flattened, rectangular; front semicircular; surface smooth, marked towards the margin with few, irregu-
lar, longitudinal ridges. Length six lines, width seven lines.

PRopUCTA LOBATA. Sow.
Productus lobatus. Sow. Min. Con.—Producta lobata. Phil. Geol. York.

Sp. Ch.—Subcylindrical, ears small, acute; dorsal valve divided into two lobes by a deep, mesial sul-
cus; radiating ridges thick, rounded, smooth, finer, and reticulated by concentric wrinkles on the rostral portion ;
a few small spines, irregularly placed.

This species closely resembles the Prod. concinna, differing chiefly in the greater coarseness of the longitu-
dinal strize, and its very deep, mesial depression. Length eight lines, width nine lines.

Propucta LONGISPINA. Sow.
Productus longispinus and P. Flemingii. jSoz. Min. Con.
Sp. Ch.—Eared, dorsal valve gibbous, with a mesial depression; obsoletely ribbed longitudinally, with se-
veral very long, cylindrical spines.
This little species is chiefly remarkable for the great length ofthe spines; it is very common in the Scotch
millstone grit, but is rare with us. It resembles the P. concinna, but is much smaller, neater, more finely stri-
ated, and has a smaller portion of the beak reticulated. Length about five lines, width the same.

PRODUCTA MARGARITACEA. Phil.
Producta margaritacea. Phil. Geol. York.

Sp. Ch.—Semicircular, depressed ; gibbous towards the beak ; radiating ribs coarse, rounded, smooth ; a few
large spines on the ears and sides of the shell.

This species bears a considerable general resemblance to the P. pectinoides, but is wider, greatly more de-
pressed, and the radiating ribs are much smaller, more convex, and do not divide in the remarkable manner of
that species; the present shell has also large lateral spines, of which the other has seldom any trace. Length
one inch, width one inch three lines.

Propucta Martini. Sov.

Anomites productus. Martin, Pet. Derb.—Productus Martini. Sow. Min. Con.

Sp. Ch.—Semicylindrical, very long, expanded at the margin; front flat; surface irregularly spinous, with
smooth, flexuous, frequently branched strie ; ventral valve flat on the top; length nearly three times the width.

112 SYNOPSIS OF THE CHARACTERS OF THE

This shell has become celebrated from giving its name to the present genus; the front is produced to a
length unusual even im this genus, whence Martin’s name; the spines on the sides of the shell, at the base
of the ears, are sometimes two and a half inches in length, and curved outwards. The flat, rostral portion
of the ventral valve has generally a smooth margin, about a line in breadth. Length two and a quarter inches,
width one inch.

Propucta MAxIMA. M‘Coy. (Pl. XIX. fig. 12).

Sp. Ch.—Twice as wide as long; gibbous; front flattened; beak large, undefined; both valves coarsely
striated ; striae slightly waving.
This gigantic shell is considerably the largest known species of the genus. The hinge-line is wide, the

beak very gibbous, but the front is broad and flattened. Width frequently one foot.

PRODUCTA MEMBRANACEA. Pil. sp.

Leptena membranacea. Phil. Pal. Fos.

Sp. Ch.—Semicircular, flat; substance of the shell very thin, with numerous close, concentric, undulating
wrinkles; spines few, irregularly placed.

This delicate species occurs im great abundance in the carb. slate series of Ireland, but the characters are
not very decisive, and it seems very nearly allied to the P. fragaria.

PropuctTa MESOLOBA. Phil.
Producta mesoloba. Pl. Geol. York.

Sp. Ch.—Subquadrangular, gibbous; front concave, with a central, narrow, convex ridge; surface smooth,
transversely wrinkled at the beak, with large, scattered, adpressed spines.

The specific name indicates one of the most remarkable characters of this species, namely the mesial lobe,
which is situated in the centre of a wide hollow in the middle of the dorsal valve; the surface is smooth, except
at the beak, where it is concentrically wrinkled; the spines are large, irregularly placed, and adpressed, so that
their points are directed towards the beak. The ventral valve is concave, with a central sulcus, corresponding
to the mesial ridge of the dorsal valve; the hinge-line is a little shorter than the width of the shell, so that the
ears are obtuse, angled. Length one inch, width one and a quarter inches.

Propuctra muricaTa. Phil.
Producta muricata. Phil. Geol. York.

Sp. Ch.—Semicylindrical, short, very gibbous, front convex; regularly ribbed from the beak with large,
rounded ribs, muricated by strong, regularly-placed spines.

This species is distinguished from every other by the extreme regularity of its strong, radiating ribs, which
are ornamented from the beak to the margin by large, equi-distant, spiniform tubercles, the tubercles of one rib
alternating with those of the next; the ears are short, square, depressed. Length one inch, width the same.

Propucta ovauis. Phil.
Producta ovalis. Phil. Geol. York.

Sp. Ch.—Longitudinally ovate, very gibbous; mesial furrow slight; ventral valve nearly flat; surface
with numerous, undulating, transverse ridges, having numerous, very small spines.

This rare species is at once distinguished by the length of the ventral valve rather exceeding the width, so
as to give a regularly ovate outline; the number and small size of its spines, and fine, concentric wrinkles,
distinguish it from the P. pustulosa, which it most resembles. Length nearly two inches, width one inch seven
lines.

CARBONIFEROUS FOSSILS OF IRELAND. 113

Propuctra PECTINOIDES. Phil.
Producta pectinoides. Phil. Geol. York.

Sp. Ch.—Orbicular, very gibbous; without spines; radiating ribs broad, smooth, rounded, each divided
into three or four, near the margin; ears short, square.

This species, and the P. margaritacea, should form a subgeneric group; the structure of their shell is
very thin, foliaceous, differing entirely from that of the other Producte. have not seen the internal struc-
ture. The present species is nearly hemispherical, with short, square ears; the forking of the ribs near the
margin is very remarkable. Length ten lines, width one inch three lines.

PRODUCTA PRELONGA. Sow. SP.

Lepteena prelonga. Sow. Geol. Trans.

Sp. Ch.—Subcylindrical, very gibbous; mesial furrow shallow ; beak of the dorsal valve large, obtuse ; ears
very small; longitudinal strie strong, unequal.

This species resembles the P. setosa, but is distinguished by the coarse, irregular strie, and large, tumid
beak; the front is also more produced than is usual with that species. Length eleven lines, width nine lines.

Propucta pucinis. Phil.
Producta pugilis. Phil. Geol. York.

Sp. Ch.—Subcylindrical, quadrangular, front flattened; sides steep, flattened, parallel; ears small, cylin-
drical, acute; radiating ridges thick, smooth, equal; a few very large, scattered spines. Breadth of the front
equalling its length.

In general form this resembles the Producta sulcata, but differs in the unusually large spines, which are
very irregularly placed; the radiating ridges are equal in size, and the surface would be regular were it not that
wherever one of the large spines occurs, three or four of the striae become raised, forming a kind of rib from its
base to the margin; this gives the shell an irregularly ribbed appearance, and frequently conveys the impression
of the striz being unequal in size; the ears are small and acute, appearing to project from the middle of the flat
side; the mesial hollow is most distinct on the rostral portion of the shell; the sides of the beak are reticulated
by a few concentric wrinkles. Length one inch six lines.

PropucTA PUNCTATA. Sow.
Productus punctatus. Sow. Min. Con.—Producta punctata. Phil. Geol. York.

Sp. Ch._—Shell rounded, wider than long, convex, with a slight mesial depression ; transversely sulcated,
the intermediate broad ridges spinulose.

In this species there are usually about fourteen or fifteen flat, concentric ridges, about a line and a half in
depth; hispid, with small, cylindrical spines, when these are broken away, as is usually the case, the ridges
appear as if punctured with a pin, whence the specific name. The ventral valve is but slightly concave, with
a mesial ridge corresponding to the hollow in the dorsal valve. Length one inch seven lines, width two inches.

Propucta pustuLtosa. Phil.
Producta pustulosa. Phil. Geol. York.
Sp. Ch.—Rotundato-quadrate, gibbous; beak pointed; a distinct mesial hollow; the entire shell girt

with regular, broad, rounded wrinkles, on which the small, oval tubercles are regularly arranged in transverse
rows, except on the ears, where the wrinkles are smooth.

2p

114 SYNOPSIS OF THE CHARACTERS OF THE

This species has the same general shape as the Producta scabricula, but is considerably larger; it differs
from it in having the entire surface covered by distinct, transverse undulations, which are quite smooth on the
ears and sides of the shell, but on the other parts bear small, lengthened, close-set tubercles. Length two
inches, width two inches and a quarter.

Propucta QuincuncraALis. Phil.

Producta quincuncialis. Phil. Geol. York.

Sp. Ch.—Hemispherical; hinge-line exactly the width of the shell; front margin semicircular; usually
without a mesial hollow; surface with coarse, longitudinal striz, swelling alternately into lengthened tubercles.

This species is often confounded with the Producta scabricula, its nearest affininity is, however, perhaps
to the Producta antiquata; the structure of the tubercles is curious, and will, at any time, distinguish this
species from the Producta seabricula ; in the present shell they are merely a thickening, at intervals, of the
radiating ribs, while in the Producta seabricula they form distinct, unconnected tubercles, bearmg at their
lower extremity a small spine. Stress is sometimes laid on the distinguishing character of Producta scabricula
having a deep mesial hollow, and the Producta quincuncialis being without one; although this is generally the
case, yet specimens of Producta scabricula occasionally occur without a mesial hollow, and Producta quincun-
cialis as often has one. It never attains the same size as Producta antiquata, and may be distinguished by
having its front wider, and more nearly semicircular, its sides striated, its beak much more gibbous, and by
having the concentric wrinkles at the beak fewer, and never assuming the large, rugged, spinous character at the
sides, which we see in the Producta antiquata. Length one and a half inches, width two inches.

Propucta RuGATA. Phil.
Producta rugata. Phil. Geol. York.

Sp. Ch.—Orbicular, depressed ; hinge-line short ; surface with few, large, irregular, concentric wrinkles,
and scattered spines; no mesial furrow.

This scarce species is very much depressed; the cardinal angles are flattened, so as to give something of an
eared appearance to the shell; the concentric undulations are few in number, obtuse and irregular; seldom ex-
tending more than half way across the shell; the tubercles are large, scattered, and very few in number. The
length seven lines, width six and a half lines, depth three lines.

:

PRODUCTA SCABRICULA. Sow.

Productus scabriculus. Sow. Min. Con.—Producta scabricula. Phil. Geol. York.

Sp. Ch.—Semicircular, gibbous; mesial hollow wide ; surface with numerous, oblong tubercles, arranged in
quincunx, each having at its anterior end a small spine, directed towards the margin. Length two-thirds the
width.

This species has in general a wide mesial hollow, but specimens sometimes occur in which it is not visible ;
there are irregular, faint, concentric undulations; the tubercles, when well preserved, are found to be the bases
of exceedingly small spines, which are placed at the end, next the margin of the shell ; the ears are rectangular
and wrinkled. Length one inch nine lines, width two inches four lines, depth one inch.

Propucta Scotica. Sow.
Productus Scoticus. Sow. Min. Con.—Producta aurita (pars.) Phil. Geol. York.
Sp. Ch.—Semicircular, twice as wide as long; ears large, flattened, gibbous towards the beak; radiating

striz fine, obtuse, flexuous; more or less wrinkled transversely ; the bases of cylindrical spines irregularly scat-
tered over the surface.

CARBONIFEROUS FOSSILS OF IRELAND. 115

This species is frequently confounded with the Producta hemispherica, but is wider, and usually more
depressed ; the large spines completely distinguish it from that species.

Propucta seTosa. Phil.
Producta setosa. Phil. Geol. York.
Sp. Ch.—Subcylindrical, semicireular, very gibbous; ears flattened, distinct, rectangular; surface strongly
striated from the beaks; irregularly spmous; length and breadth equal.
This species resembles the Producta spinosa, but is much more distinetly striated ; the hinge-line is longer,
and the ears larger, and more distinct. Length three quarters of an inch.

PrRopUCTA SPINOSA. Sow.
Productus spinosus. Sow. Min. Con.
Sp. Ch.—Rounded, very gibbous; obsoletely ribbed, longitudinally ; with very long, cylindrical spines;
hinge-line very short; no mesial furrow.
This differs from all the nearly allied species in being marked by faint, rounded, smooth, radiating ribs;
the spines, when well preserved, are perfectly cylindrical, and sometimes nearly two inches in length; the hinge-
line is so short, that the back of the shell is much rounder than the front. Length nine lines, width eight lines.

PRopucTAa sPINULOsA. Sow.
Productus spinulosus. Sow. Min. Con.—Producta spinulosa. Phil. Geol. York.
Sp. Ch.—Semicircular, depressed, without mesial hollow; beak large, gibbous; surface smooth, with many
small spies.
The ventral valve of this scarce little species is very concave; the hinge-line is long and straight, the ears
square, flattened; the beak is very large, inflated. Length six lines, width nine lines.

PropucTA stRIATA. Mischer. sp.
Mytilus striatus. Mischer. Oryctol. Mos.—Pinna inflata. Phil. Geol. York.—Producta limezformis. De Buch. Mon. Prod.—

Producta anomala. Sov. Min. Con.

Sp. Ch.—Shell large, trigonal, very irregularly conic, depressed; surface with close, small, waving strie,
which are usually rounded, or slightly flattened.

This curious shell seems to me to be the type of a new and peculiar genus; in form and general habit it
certainly resembles Pinna very closely, in which genus Professor Phillips has placed it, but is distinguished by
one valve being concave and the other convex. Fischer originally referred it to Mytilus, from which it dif-
fered in having one valve concave, and in wanting a hinge-line. Von Buch and Mr. Sowerby have placed it
in Producta, from which it seems to differ in not being eared, and, in fact, entirely wanting the straight hinge-
line of that genus; the small, narrow, pointed beaks, and general form, are at variance with the usual charac-
ters of the genus.

The present species is very irregular in form, some specimens being almost cylindrical, while others are
almost as broad as long, and flattened; the striation is not subject to so much variation; on most specimens the
strie are smooth and rounded, but irregular in size; they are all flexuous, but irregularly so. Length one foot,
width five inches.

PropucTa suBACULEATA. Murch. and De Ver.
Leptena subaculeata. De Ver. Bul. Geol. Soc. de Trans.

The specimens referred to this species only differ from the Z. aculeata, in having the spines perpendi-
cular to the surface, instead of being adpressed, as in that species. They are less wide, and have rather fewer
spines than the P. granulosus.

116 SYNOPSIS OF THE CHARACTERS OF THE

PRODUCTA SULCATA. Sov.
Productus suleatus. Sow. Min. Con.—Producta suleata. Phil. Geol. York.

Sp. Ch.—Semicylindrical, front flattened, with parallel sides; mesial hollow small, shallow; longitudinal
ribs very thick, rounded, at imtervals spinous, decussated near the beaks by slight, concentric wrinkles, a row of
large spines on each ear.

This species is sometimes likely to be confounded with some varieties of the P. antiquata, but differs in its
smaller size, greater proportion of length to width, more strictly parallel sides, and the top of the smaller valve
being flat; the radiating ribs are also much larger and smoother. Professor Phillips unites the Producta cos-
tata, Sow., to this species; but the specimens I have been able to examine of this latter agreed strictly with
Mr. Sowerby’s figure and description in the Mineral Conchology; and even fragments may be distinguished by
the shape of the longitudinal ridges in each, so that it may, perhaps, be as well to keep the species distinct. I
have only seen the Producta costata from the original locality in which they were found by Mrs. Murchison,
namely, the Glasgow coal shale, while the Producta sulcata is common in many limestone districts in Ireland.

Length two inches, width one inch and a half.

Propucta Tortinis. M‘Coy. (Pl. XX. fig. 14).

Sp. Ch.—Semicircular, convex; rostral portion rather depressed; front deflected, rounded ; entire sur-
face marked with close, fine, rounded, longitudinal strie ; and transverse, interrupted, irregular, waving wrinkles.

This remarkable species is, perhaps, most nearly allied to the P. Scotica, Sow., and it also bears some re-
semblance to the P. fragaria ; but both those species are distinctly spinose, while the present shell is altogether
without spines: from the P. hemispherica, Sow., and P. corrugata, M‘Coy, it is distinguithed by the depres-
sion of the rostral portion, and by the irregular, transverse, wrinkling, or crumpled appearance of the whole sur-
face. Length one inch, two lines, width one inch six lines.

Lepraconia. M‘Coy.

Gen. Ch.—Shell transverse ; rostral portion flat, concentrically wrinkled; front smooth, abruptly deflected .
at right angles to the flat, rostral portion; cardinal area flat, with a large (obtect) triangular foramen.

The remarkable fossils which I separate under this name have all a peculiar contour, from the distinct
angle which separates the flat, wrinkled, rostral part of the shell, from the smooth, deflected front. Von Buch
places the shells which enter into the present genus among the Delthyride or Spirifers, a position which almost
every other author denies; most writers agreeing that they should be placed among the Producte, with which
they certainly agree in all their important characters, excepting the cardinal area and foramen. It is by this
group that the Athyride ox Productas pass into the Delthyride or Spirifers, uniting in itself the characters
of the two groups. The generic characters above given are merely those external ones which can be easily found in
the worst preserved specimens, and will distinguish even fragments from the other ge- Fig. 11.
nera of the Productas. The internal structure differs very much from that of the other
groups; the muscular impressions are four ineach valve. In the dorsal valve the prin-
cipal pair of adductor muscles (a a, fig. 11) arise each from a large, rounded, radiatingly

a slight, shelly septum (c); the cicatrices of the lesser adductors (B B) are much smaller
than the others, pear-shaped, the anterior end being rounded, the posterior attenuated,
smooth; they take their origin interiorly, and a little anterior to that of the great pair. In this valve we also
observe two large cardinal teeth (p ), perfectly resembling those of Orthis. In the ventral valve the attach-

CARBONIFEROUS FOSSILS OF IRELAND. 117

ments of the principal pair ofadductor muscles, form two hemispherical smooth cicatrices (a 4 fig. 12), about halfthe
size of those in the dorsal valve; they are nearly half their diameter dis- 4 Fig. 12. Jig. 13.

tant from the hinge-line; considerably anterior to them are the two elon- i
gated, pear-shaped origins of the lesser pair of adductors (B B); they | I
differ from those in the dorsal valve in being smaller, and having their KK 4
attenuated extremities directed anteriorly instead of posteriorly; they QS
are divided by a thin, shelly septum; figure 13, a a, shews the perfect eB
form of the cardinal teeth in the next species.

LEPTAGONIA ANALOGA. Phil. sp.

Producta analoga. Phil. Geol. York.—Leptena analoga. Sov. Geol. Trans.

Sp. Ch.—Rostral portion flat, slightly convex in the middle; about fourteen irregular, concentric ruge,
erossed by rather coarse, straight striae from the beak; front short, flattened in the middle. Length about one
inch, width two inches.

This species has been well separated from the Producta depressa, Sow., by the accurate author of the
Geology of Yorkshire, although many observers still confound the two. It differs from the Producta depressa
in having the flat part of the valves much less depressed than in that species; the concentric ruge are double
the number, and the size nearly twice the usual dimensions of the Producta depressa of the Silurian rocks; the
front, or deflected portion, is flattened, or even concave in the middle, and in well preserved specimens extends
beyond the hinge-line, forming smooth, rounded ears; the concentric wrinkles are rounded, irregular; the two
valves are alike; the cardinal area about a line in width, transversely striated; the triangular foramen is
large.

LEPTAGONIA DEPRESSA. Sow. sp.
Producta depressa. Sow. Min Con.—Leptena depressa. Sow. Sil. Res.

Sp. Ch.—Subquadrate; flat part of the valves very much depressed; about ten irregular concentric wrin-
kles, crossed by straight, radiating striz.

The specimen above described is the first I have known from the mountain limestone. Professor Phillips’
specimen, to judge from the figure, looks more like the Z. rugosa. The present species is smaller, and nar-
rower in proportion than the foregoing; the flat portion of the valves is also much more depressed, so much
so, that the angle which separates it from the descending front forms a prominent border to it all round;
the front is flattened in the middle, and at the sides, thus giving a quadrangular contour to the shell. Length
five lines, width seven lines.

LepTaGona MuttTinuGaTa. MM‘Coy. (Pl. XVIII. fig. 12).

Sp. Ch.—Top of the upper valve flat; closely striated, with about twenty-two concentric ruge, which
frequently unite in pairs as they approach the hinge-line; hinge-line straight, equal to the breadth of the shell ;
length, three-fifths the breadth.

This shell, as well as the Producta analoga of Professor Phillips, has been frequently confounded by
geologists, with the L. depressa of the Silurian rocks; this latter, however, I have seen very rarely in undoubted
mountain limestone, nor do I know that either of the former have been found in any of the Silurian range.
The present shell is distinguished from the nearly allied species, L. depressa, L. analoga, and L. tenuistriata,
by having the top of the upper valve perfectly flat, neither sensibly convex nor concave, as in those species.
The concentric furrows are greatly more numerous in the present shell; these in Leptena analoga are about
thirteen or fourteen, in Leptena tenuistriata twelve, and in L.depressa muchless. Breadth of the shell about
an inch.

2G

118 SYNOPSIS OF THE CHARACTERS OF THE

LEPTAGONIA NopuLOSA. Phil. sp.
Leptena nodulosa. Phil. Pal. Fos.

Sp. Ch.—Shell semicircular; concentric ruge disconnected, very irregular, crossed by extremely fine,
flexuous striz; deflected front, undulated, so as to make the angle which separates it from the rostral portion
somewhat nodular; the front is not flattened in the middle.

This is a larger, wider, and more irregular species than the L. analoga ; the concentric wrinkles on the flat,
rostral portion are very short and irregular, and do not extend the whole width of the shell; in the LZ. ana-
loga they are decussated by rather coarse, straight, radiating striz, while in the present species the radiating
striz are remarkably fine and waving. The deflected front is so much undulated, that it appears almost nodu-
lar, whence the specific name; it wants also the mesial depression of that species. It is difficult to say whether
this is really distinct from the common ZL. analoga, for instance, it is usually found much larger than that spe-
cies, but that might only shew it to be an adult individual; then, again, the irregularity of the deflected margin
and concentric ruge are just the characters we would expect to arise from extreme age; the radiating strie I
have found to vary very much in thickness, &c., according to the preservation of the specimens; yet there
appears to be a peculiarity of contour, which, together with its being most abundant in the Devonian rocks,
renders it desirable to retain Professor Phillips’ specific name. Length one inch three lines, width two inches

nine lines.

LEPTAGONIA PLICATILIS. Sow. sp.
Productus plicatilis. Sow. Min. Con.—Producta plicatilis. Phdl. Geol. York.

Sp. Ch.—Rostral portion convex, with a deep, narrow, mesial hollow, and sixteen or seventeen small,
rounded, concentric wrinkles, irregularly spinose; a row of three or four large spines on each side the beak;
deflected front smooth.

This is obviously an aberrant species, leading to the ordinary Productas by its convex, rostral portion, and
also by its having a mesial hollow and large spines. In well preserved specimens the front is perfectly smooth,
even the fine, radiating strie being there obsolete. Length seven lines, width eleven lines.

LEPTAGONIA RUGOSA. Dal. sp.
Leptena rugosa. Dal.

Sp. Ch.—Subrhomboidal, front straight, deflexed margin short; flat portion of the valves with fine,
regular, rounded, concentric undulations, crossed by coarse, direct, equal, radiating striz.

This species is very rare in the mountain limestone, and, when it does occur, is often confounded with the
P. analoga, Phil., from which it differs entirely in its striation, and in the great regularity of the transverse
wrinkles.

Leprezna. Dal. (Restricted).

Gen. Ch.—Semicircular, thin, seale-like; finely striated longitudinally; dorsal valve convex, ventral valve
nearly equally concave; hinge-line as long as the shell is wide, usually armed with spines; cardinal area dis-
tinct, flat, with parallel sides, having a central, triangular, nearly closed foramen.

The genus, as here restricted, includes all those elegant, nearly flat, striated, scale-like shells, so abundant
in the Silurian rocks, but rare in the carboniferous series. They are distinguished from Orthis by their nar-
row, cardinal area, with parallel sides, the area of Orthis being triangular, or rhomboidal, when distinctly com-
mon to the two valves; the hinge-line is never less than the width of the shell, and frequently armed with
comparatively large spines, in which they differ from the true Orthide, which are never spinose.

CARBONIFEROUS FOSSILS OF IRELAND. 119

Leprana convotuta. Phil.
Leptena convoluta. Phil. Pal. Fos.
Sp. Ch.—Transversely fusiform, gibbous, convoluted; ears conical; surface with coarse, longitudinal,
rounded striz.
A rare species, easily distinguished from the Z. volva, M‘Coy, by the coarse, direct striz of the surface. I
am not aware whether spines have been detected on the hinge-line; the Irish specimens do not shew any.

Leprana crassistriA. M‘Coy. (Pl. XX. fig. 10).

Sp. Ch—Semicireular, convex; length two-thirds the width; beak large, gibbous; surface with about
twenty-eight coarse, rounded, radiating ridges; ears smooth, flattened; hinge-line spinous.

This well-marked species is very abundant in certain localities. The radiating ribs are sharp, equal,
rounded, and about equal in width to the spaces between them; the ears are smooth, and much flattened ;
there are about twelve short, slender, curved spines on the hinge-line. Length five and a half lines, width
seven and a half lines.

LEepTHNA DALMANIANA. Kon.

Sp. Ch.—Semicircular, flat, nearly twice as wide as long; surface covered with very fine, flexuous striz ;
ten or twelve slender spines on the hinge-line.

The striz on this beautiful species are so fine, as to be indistinctly seen with the naked eye; they are
flexuous; the substance of the shell is very thin, and both valves are perfectly flat; the spies on the hinge-
line are short and slender. Length eight lines, width thirteen lines. Before receivmg De Koninck’s work I
had figured this species, Pl. XX. fig. 7.

LEPTHNA GIBBERULA. M‘Coy. (PI. XX. fig. 11).

Sp. Ch—Semicireular, length two-thirds the width, very gibbous in the middle; ears acute, flattened ;
surface very finely and regularly striated longitudinally.

This curious little species is not uncommon in the carb. slate series of Ireland, the shales of which abound
with small species of Orthis and Leptena, from all of which the present is distinguished by the great gibbosity
of the middle portion, or body of the shell, the flattened, acute ears, and the nearly smooth surface, the longi-
tudinal stri being so fine as to require the lens to render them distinctly visible; they are close, rounded, and
perfectly equal, in which they differ from the Silurian L. sericea, Sow., with one of the varieties of which it is
likely to be confounded. Length one and a half lines, width three lines.

LepranA Harprensis. Phil. sp.
Orthis Hardrensis. Phil. Pal. Fos.

Sp. Ch.—Semicircular, one valve convex, the other slightly concave; hinge-line equal to the width of the
shell, armed with ten short, cylindrical spines; surface strongly striated from the beak; striz crossed by minute,
transverse lines; internal surface rough, with small, depressed spines; impressions large, reniform.

It closely resembles the L. lata of the Silurian rocks. The L. sarcinulata of continental authors seems to
include them both.

Leprana LATA. De Buch. (?)

Leptena lata. (?) Sow. Sil. Syst.

A few fragments of a Leptena, possibly of this species, have occurred very rarely, but it is possible they
might be referred to some of the varieties of the preceding species.

120 SYNOPSIS OF THE CHARACTERS OF THE

LEPTENA MULTIDENTATA. M‘Coy. (PI. XX. fig. 8).

Sp. Ch.—Semicircular ; dorsal valve convex; ventral valve slightly concave; hinge-line straight, furnished
with about twenty-six short, toothed spines; cardial area triangular, narrow, smooth; both valves coarsely striated
longitudinally ; striz often dichotomizing; the intervening sulci regularly punctured.

This fine species is distinguished from every Leptena I know, by the great number of short, strong spines
on the hinge-line; the dorsal valve is convex towards the beak, flattened towards the cardinal angles; the lon-
gitudinal striz are coarse, rounded, and frequently branching as they approach the margin; they are separated
by very narrow sulci regularly punctured. Length eleven lines, width one inch five lines; height of cardinal
area one line.

LEPTHNA PAPYRACEA. M‘Coy. (Pl. XXII fig. 2).

Sp. Ch.—Truncato-orbicular, length two-thirds the width, flat; hinge-line less than the width of the shell,
spinous; cardinal angles obtuse; surface radiated with sharp, filiform, unequally-branched striz, divergingly
arched at the sides; sides of the shell concentrically wrinkled.

This singular species is common in one or two localities. It is distinguished from all others of the genus
by the corrugated sides; it is perfectly flat, and as thin as paper; the hinge-line is considerably less than the

width of the shell, and is closely set with long, hooked, slender spines. Length ten lines, width eleven
lines.

LEPTHNA PERLATA. M‘Coy. (Pl. XX. fig. 9).

Sp. Ch.—Semicireular; nearly twice as wide as long, convex; front margin nearly straight; surface
marked with very fine, longitudinal, slightly flexuous striz; hinge-line with about eight long, slender spines,
set nearly at right angles.

This species is very closely allied to the Z. lata of the Silurian strata; but on comparison of specimens
the present shell is found to have the radiating strie very much finer than either the Silurian species, or the O.
Hardrensis of Phillips, and that they are slightly flexuous, nor is there any mesial depression in the present
shell. Length three lines, width five and a half lines.

LEepTmna PLICATA. Phil. sp.
Orthis plicata. Phil. Pal. Fos.—Orthis plicata. Sow. Geol. Trans.

Sp. Ch.—Transversely elliptical; width more than twice the length, extremities rounded, depressed ; sur-
face with about thirty coarse, sharp, radiating ridges, which become doubled in number as they approach the
margin.

This species seems closely allied to that which I have figured under the name of Leptena serrata, but is dis-

tinguished by its angular plaits, and rounded extremities; the radiating ridges are striated transversely. Length
three lines, width seven lines.

LEPTENA SERICEA. Sow. (?)
Leptena sericea. Sow. Sil. Syst. ?—Leptena interstrialis. Phil. Pal. Fos.

Sp. Ch.—Semicircular, gibbous; very finely striated every fifth or sixth line, forming a sharp sulcus.

The few specimens of this shell which have occurred to me are obviously identical with the Leptena
interstrialis of Phillips. That author states, that on comparison with specimens of the L. sericea, his shell
seemed distinct. Ido not, however, see any very clear distinction in the Irish specimens, and they are referred
to that species for the present, until more perfect specimens may occur. Length about seven lines.

CARBONIFEROUS FOSSILS OF IRELAND. 121

Leprmna serrATA. M‘Coy. (Pl. XVIII. fig. 10).

Sp. Ch.—Semicircular, convex ; surface covered with numerous, rather coarse, branched ridges ; hinge-line
equal to twice the length, straight, furnished with twenty small, hooked spines.

This species has been confounded with the Z. data of the Silurian rocks. It has, however, twenty short,
hooked spines on the hinge-line, while that has but eight, or ten at most, long and slender ones. The thick,
dichotomous striz are likewise so characteristic, as to enable the geologist to distinguish even small fragments
of the two species. Breadth ten lines, length five lines. One of the rarest fossils we have.

LEPTANA SORDIDA. Sow.
Leptena sordida. Sov. Geol. Trans —Orthis sordida. Phil. Pal. Fos.

Sp. Ch.—Outline from subquadrate to nearly semicircular; slightly convex; finely striated longitudinally ;
strie granulated near the margin.

This pretty species is nearly allied to the O. Hardrensis, Phil., but is distinguished by its greater length
in proportion to the width, and the strie being granulated near the margin; the internal structure is also very

different. Length four lines, width six and a half lines.

LEPTENA TUBERCULATA. M‘Coy. (Pl. XX. fig. 5).
Sp. Ch.—Semicircular, convex ; length two-thirds the width; surface with about forty-eight thick,
rounded, dichotomous, smooth ribs, each bearing towards the margin a row of from five to eight round tubercles.
This curious little species is nearly semicircular, the hinge-line bemg much shorter than the width of the
shell; moderately convex; the radiating ribs are thick, smooth, and distinctly separated, branching as they
approach the margin, where they bear a row of six or eight little round tubercles. Length five lines, width

eight lines.

Leprana votva. M‘Coy. (Pl. XVIII fig. 14.)

Sp. Ch.—Semicircular, gibbous; ears involute, separated from the body of the shell by a shallow depres-
sion; hinge-line twice the length of the shell, furnished with twenty-four slender, hooked spines; surface
covered with very fine, flexuous striz.

This pretty species resembles the Z. convoluta in general form, but is distinguished by the exceedingly
fine, flexuous strie ; the two valves are almost in contact, the ventral valve being nearly as concave as the dor-
sal is convex; the cardinal area is very narrow, concave, and with parallel sides. Length eight lines, width one

inch four lines.

Ortuis. Dalman.

Gen. Ch.—Shell semicircular; dorsal valve convex in the middle; ventral valve nearly flat, slightly con-
vex or concave; cardinal area trianeular, common to both valves, that of the dorsal valve reticulated by
muscular striz, a large triangular foramen in the centre, nearly closed by arched scales; no spiral appendages ;
dental lamellz semicircular, curving towards each other at their extremities.

ORTHIS ARACHNOIDEA. Phil.
Spirifer arachnoidea. Phil. Geol. York.—Orthis arachnoidea. Phzl. Pal. Fos.
Sp. Ch.—Semielliptical, flat; hinge-line equal to the width of the shell; length exceeding the width;
surface with numerous sharp, fine, close, divaricating strie, increasing very much in number towards the
margin, a few equidistant sulci deeper than the rest.

2) Ei

122 SYNOPSIS OF THE CHARACTERS OF THE

This elegant species is very rare in the Ivish limestone series, where it has been occasionally confounded
with the O. pecten, which it much resembles. Length one inch nine lines, width one inch eight lines.

OrTHIS ARCUATA. Phil.
Orthis arcuata. Phil. Pal. Fos.

Sp. Ch.—Transversely oval; twice as wide as long, flattened; beaks small, prominent; ventral valve with
a slight mesial hollow; surface with fine, divaricating striz, much curved at the sides.

This species is rare; it is wider, and the strize are more curved than in O. interlineata. Length six lines,
width eleven lines.

Ortuis Becuer. M‘Coy. Pl. XXII fig. 3).

Sp. Ch.—Semicircular, depressed; nearly twice as wide as long; front straight, slightly convex; sides
abruptly rounded, nearly straight, forming rectangular cardinal angles; hinge-line equal to the width of the
shell; cardinal area wide, triangular; surface closely radiated with fine, very much branched, equal striz
(about twenty-six in half'an inch of the margin); intervening spaces narrow, concave, sharply striated across.

This fine species differs from the O. erenistria, in being so much more finely striated, and the strize
being equal in thickness, although, of course, very unequal in length, from their increasing so much in number
towards the margin, and from the O. arachnoidea, Phil., in its great width, transverse striation, cardinal
area, &c. From the nature of the striation, fragments are liable to be confounded with the Atrypa desquamata.
From the O. comata, M‘Coy, it is easily distinguished by its sharp, straight, frequently branching striae, and
their greater distance; the striz in that species being remarkably obtuse, close, and flexuous, very seldom
branched, and much finer, there being about eleven stria in a quarter of an inch at the margin of the O. Bechei,
and twenty-one in the same space of margin of the O. comata. Length one inch three lines, width two
inches. Dedicated to Sir Henry T. De la Beche.

Ortuis capuca. M'Coy. (Pl. XXII fig. 6).

Sp. Ch.—Orbicular; perfectly flat, thin, width slightly exceeding the length; hinge-lne shorter than
the width of the shell; surface radiated with very numerous, fine, dichotomous strie, of unequal length and
fineness, slightly arched at the sides; intervening spaces flat, finely striated transversely.

This beautiful shell is distinguished from Captain Portlock’s O. cancellata, by its short hinge-line, more
numerous and finer striz; the transverse strix being much more delicate in the present shell. Length eight
lines, width ten lines.

OrTHIS crrcuLaRis. M‘Coy. (Pl. XX. fig. 19).

Sp. Ch.—Outline circular; hinge-line less than one-third the width of the shell; valves nearly equal;
very slightly convex, radiated with thick rounded ridges, which are decussated by delicate, transverse striae,
and numerous, strong, scale-like lines of growth; besides these there are a few scattered erect scales on the
ridges.

This little species is remarkable for its almost perfect circularity of outline; the valves are but slightly
convex, coarsely ribbed; the beaks are very small, but prominent; a few irregular, erect scales on some of
the ribs give an irregularly tuberculated appearance to some specimens. Length five lines, width the same.

Ortuis comaTa. M‘Coy. (Pl. XXII. fig. 5).
Sp. Ch.—Truneato-orbicular ; hinge-line as wide as the shell, extremities rectangular ; cardinal area large,
triangular; beaks large, prominent; surface marked with very numerous, fine, longitudinal ridges, or stria, ob-
tusely rounded, close, equal, and slightly waving, very finely striated across.

CARBONIFEROUS FOSSILS OF IRELAND. 123

In form this resembles the O. erenistria, but is easily distinguished by its very numerous, flexuous, rounded
stria, which, instead of bemg unequal in length and thickness, and separated by broad, flat, spaces, as in that
species, are in the present shell equal, and perfectly close together, resembling coarse, flowing hair; the obtuse,
flexuous, and very numerous strie distinguish it from the O. Bechet, M‘Coy (see O. Bechet). Length one inch
six lines, width two inches seven lines.

ORTHIS COMPRESSA. Sow. (?)
Orthis compressa. Sow. (?) Sil. Syst—Orthis compressa. Phil. Pal. Fos.
Sp. Ch.—Truncato-orbicular, depressed ; length and width nearly equal; surface with very fine, radiating

strie, having between them rows of impressed puncta.
A few imperfect specimens, apparently of this species, have occurred.

OrTHIS CONNIVENS. Pil. sp.
Spirifera connivens. Phil. Geol. York.
Sp. Ch.—Globose; front margin much raised and sinuated; a mesial hollow, bounded by two obtuse

ridges, in each valve; surface with coarse, radiating striz.

ORTHIS CRENISTRIA. Phil.
‘Spirifera crenistria. Phil. Geol. York.—Orthis crenistria. Sow. Geol. Trans.—Orthis crenistria. Phil. Pal. Fos.

Sp. Ch.—Semicireular; cardinal area large, strongly striated; foramen nearly closed by vaulted scales;
greatest depth of convex valve about one-third from the beak; radiating stria strong, sharp, unequal in thick-
ness, increasing in number towards the margin; spaces between the radiating striz flat, sharply striated across.

In old individuals the front becomes as much deflected as in the Leptena euglypha.

Ortuis cytinpRica. M‘Coy. (Pl. XXII. fig. 1).

Sp. Ch.—Ventral valve semicircular, evenly convex, very gibbous towards the beak; deflected front very
long, convex, cylindrical; surface marked with fine, longitudinal ridges, every fourth or fifth larger than the
others; the intervening spaces slightly wrinkled transversely, with very fine longitudinal striz.

The striation of this beautiful shell is similar in character to that of the O. erenistria, O. Kellii, L. eugly-
pha, &c., but the form at once distinguishes it from every other known species ; it approaches somewhat to the
L. euglypha, but is much longer, more cylindrical, and convex; even young shells may be distinguished by all
the space near the beaks being flattened, or slightly concave in the one, but very gibbous in the other. Length
of rostral portion eight lines; length of the deflected front one inch two lines; width one inch two lines.

Ortuls pivaricaTa. M'‘Coy. (Pl. XX. fig. 17).

Sp. Ch.—Transversely oval; ventral valve evenly convex; dorsal valve plano-concave in the middle;
hinge-line very short; surface finely and regularly striated; stria at the sides much curved.

This species is much larger, and more convex than the O. arcuata, Phil., which, in some respects, it much
resembles; it is likewise more finely striated, and much less transverse, the width exceeding the length by
rather less than one-fifth, while the O. arcuata is nearly twice as wide as long; it has, also, a larger cardinal
area. Length twelve lines, width fourteen lines.

OrTHIS FILIARIA. Phil. sp.
Spirifera filiaria. Phil. Geol. York.
Sp. Ch.—Longitudinally obovate, depressed; beaks prominent; hinge-margin very short, widest towards

the front; smaller valves concave in the middle; a shallow sinus in the front margin; surface coarsely striated
longitudinally.

124 SYNOPSIS OF THE CHARACTERS OF THE

The obovate outline of this species distinguishes it from every other with which I am acquainted Length

one inch, width eleven lines.

ORTHIS GIBBERA. Portk. sp.
Atrypa gibbera. Portk. Geol. Rep.

Sp. Ch.—(Young) semicircular, convex, front margin slightly raised; (adult) semicylindrical, depth
exceeding the width; sides subparallel, rostral portion of the shell flattened; front of both valves deflected,
much produced, rounded; margin of the dorsal valve deeply lobed at the sides, raised to a narrow, rounded
sinus in front; cardinal area narrow; surface very finely striated longitudinally, every fifth or sixth line thicker
than the intermediate ones.

This curious species was figured on our plate nearly three years ago (previous to the publication of Captain
Portlock’s Report) under the specific name alta, in allusion to the great height of the valves. I have, how-
ever, of course adopted Captain Portlock’s specific name, as first published. The dorsal valve resembles a Bel-
lerophon bilobatus in shape; the striation resembles that of some varieties of the O. resupinata. Depth of
both valves one inch five lines, width one inch one line, length the same.

OrTHIS GRANULOSA. Phil.
Orthis granulosa. Phil. Pal. Fos.

Sp. Ch—Orbicular, flat; hinge-line two-thirds the width of the shell; beaks very small, pomted; sur-
face strongly radiated, with angular, granulose ridges, which become doubled in number as they approach
the margin.

A rare species, easily distinguished by its numerous, dichotomous, tuberculated strie. It resembles the
O. testudinaria and O. canalis of the Silurian rocks. Length three lines, width four lines.

ORTHIS INTERLINEATA. Sov.
Orthis interlineata. Sow. Geol. Trans. (pars.)—Orthis interlineata. Phil. Pal. Fos.

Sp. Ch.—Transversely oval, depressed; beaks small, prominent; surface with strong, radiating striz,
increasing in number towards the margin; cardinal teeth diverging, enclosing a large, cordiform space.

This species is distinguished from the O. parallela by its greater width and large cordiform impressions ;
from O. arcuata, by the directness and lesser width of its strize. Length nine lines, width one inch three lines.

Ortuts Keriru. M‘Coy. (Pl. XXII fig. 4).

Sp. Ch.—Truneato-orbicular, hinge-line slightly less than the width of the shell; cardinal angles obtuse ;
ventral valve very convex, with a wide, rounded, mesial furrow; dorsal valve shallow, slightly concave ; surface
of both valves radiated with very fine, close, unequal ridges and striz.

I am indebted to Mr. John Kelly for directing my attention to this species; it seems to be constantly dis-
tinguished from the O. erenistria, Phil., by its deep, rounded mesial furrow, which also indents the front margin,
so that it closely resembles in shape the O. bilobata, Sow.; it is also much more convex, and is particularly
gibbous near the beak, from which the surface is recularly arched to the margin, while the O. crenistria is
flattened, or slightly concave near the beak, and is either nearly flat, or in old specimens suddenly rounded
to a short, deflected margin, as in the L. euglypha; the cardinal angles of the O. crenistria, Phil., are acute,
so that the width is nearly double the length ; while, on the other hand, in the O. Kellii, M‘Coy, the cardinal
angles are obtuse, the hinge-line being rather less than the width of the shell. and the length is three-fourths

CARBONIFEROUS FOSSILS OF IRELAND. 125

the width. I have never seen the O. Kellii more than two inches in length, while the O. crenistria is fre-
quently double that size, and is almost always larger than the former species. The striation is so variable in
those shells, according to the state of preservation of the surface, that it is of little use in specific distinctions ;
the stria, however, of the O. Kellit, M‘Coy, although resembling in character those of the O. crenistria,
Phil., are usually much finer, closer, and more nearly equal, than in that species. Length one inch four lines,
width one inch eight lines.

Ortuis LatissimA. M‘Coy. (Pl. XX. fig. 20).

Sp. Ch.—Twice and a half wider than long, depressed, convex near the beak; margin slightly inflexed;
cardinal angles rounded; surface regularly and closely marked with fine, rounded strie; internal impression
large, formed of two lobes on each side, the anterior of which is dilated, and spatulate at the tip, that nearer the
beak suddenly pointed; central septum extending only as far as the lateral impressions.

This is the widest species of Orthis with which Iam acquainted; it is convex only near the beak, and the
long ears are rounded and slightly turned up as in the Leptena latissima; there is a narrow, inflexion of the
margin; the radiating striae are exceedingly fine, close, equal, rounded, and smooth; the internal supports are
very large, forming a double lobe on each side. Length eleven lines, width two inches two lines.

ORTHIS LONGISULCATA. Phil.
Orthis longisulcata. Phil. Pal. Fos.

Sp. Ch.—Transversely oval, rather more than twice as wide as long, depressed; surface radiated with very
fine, divaricating stria, increasing in number towards the margin, and in old specimens decussated by imbri-
cating lamin of growth; cardinal teeth very long, straight, diverging.

This species is allied to the O. interlineata, but is more finely striated; the long, straight teeth distinguish
it from any of the other species. Length nine lines, width one inch seven lines.

ORTHIS ORBICULARIS. Sow.
Orthis orbicularis. Sow. Sil. Syst.

Sp. Ch.—Orbicular, depressed; beak small; hinge-line nearly equal to the width of the shell; dorsal valve
convex, the other flattened, with a wide mesial hollow; both valves finely striated.
I have not seen the internal structure of this species, which is almost necessary for its recognition.

ORTHIS PAPILIONACEA. Phil. sp.
Spirifer papilionacea. Phil. Geol. York.

Sp. Ch.—Width rather more than twice and a half the length; front deflected in old specimens; surface
covered with exceedingly fine, undulating, equal strie; cardinal area narrow, rhomboidal, transversely striated.

This beautiful species with age acquires nearly the size of the Producta gigantea, and nearly the same
form, in which state it has, perhaps, been ranked with the P. comoides. When young, however, it is flat,
transversely elliptical, very wide, and with very acute cardinal angles.

OrTHIS PARALLELA. Phil.
Orthis interlineata. Sow. (pars).—Orthis parallela. Phil. Pal. Fos.

Sp. Ch.—Longitudinally ovate, depressed; surface with strong, alternately larger and smaller, divaricating,
angular strie, doubling in number as they approach the margin; cardinal teeth lengthened, slightly curved,
approximate at their tips, enclosing two long, tongue-shaped impressions.

This species is very distinct from the O. interlineata, both in form and internal structure; it approaches

21

126 SYNOPSIS OF THE CHARACTERS OF THE

much nearer to the O. filiaria of the superior beds, but has much coarser striz, and a larger hinge-line. Length
nine lines, width eight lines.

OrtuIs (?) QuADRATA. M‘Coy. (Pl. XX. fig. 18).

Sp. Ch.—Shell quadrate, pyramidal; front straight, slightly emarginate; sides slightly concave; cardi-
nal angles pointed; cardinal area very large, flat, triangular; surface with about forty strong, radiating ridges,
alternately larger and smaller.

This pretty little shell resembles the Leptena minima of the Wenlock shale in outline and size, but the
strie are coarser, and the cardinal area larger; the present species is almost pyramidal, the height at the beak
being rather more than one-half the length. Only a single specimen has occurred. Length one line and a
half, width two lines.

OrTHIS RADIALIS. Phil. sp.
Spirifera radialis. Phdl. Geol. York.

Sp. Ch.—Semicircular, twice as wide as long; convex; surface with large, irregular, rounded, radiating
ridges, with numerous, intermediate, smaller ones, all crossed by numerous, prominent, imbricating laminz of
growth.

This magnificent shell is in no danger of being confounded with any other, its characters are so bold and
striking. It is very rare.
ORTHIS RESUPINATA. Mart. sp.
Con. Anom. resupinatus. Mart. Pet. Derb.—Terebratula resupinata. Sow. Min. Con.—Spirifera resupinata. Phil.
Geol. York.—Orthis resupinata. Phdl. Pal. Fos.

Sp. Ch.—Transversely oval, length one-third less than the width; dorsal valve concave; ventral valve
evenly convex, with a mesial depression; surface with fine, radiating strie, which form lengthened, alternating
spines at irrecular intervals.

This species is liable to considerable variation, the stria are often nearly plain, some are more convex than
others, and finally some adult specimens are scarcely an inch long, while others, apparently not full grown, are
nearly three times that size, just as we see in some living species of Cyprea. Length one inch five lines,
width one inch ten hnes, depth ten lines.

ORTHIS SEMICIRCULARIS. Sow.
Orthis semicircularis? Sov. Sil. Syst.—Orthis semicircularis. Sow. Geol. Trans.—Orthis semicircularis. Phil. Pal. Fos.

Sp. Ch.—Truncato-orbicular, gibbous; radiating strie, fine, direct, increasing in number towards the mar-
gin; cardinal teeth very short, thick, and very much diverging.

I have followed Professor Phillips and Mr. Sowerby in calling this Devonian shell O. semicireularis,
although the Caradoc sandstone species appears to me to differ constantly in being wider, more convex, and
more coarsely striated.

Ortuis sutcaTa. M‘Coy. (Pl. XX. fig 6).

Sp. Ch.—Semicireular, gibbous; ears flattened; surface with very coarse, rounded, frequently branched
striz; hinge-line exceeding the width of the shell, furnished with ten strong, conical spines.

This species is easily distinguished from the Leptena volva, M‘Coy, by its flattened ears, and coarser striz,

and from O. multidentata, M‘Coy, by its greater gibbosity, coarser striz, and less number of cardinal spines.
Length nine lines, width fourteen lines.

OrTHIs (?) TENUISTRIATA. Sow.
Orthis tenuistriata. Sow. Geol. Trans.
I have referred to this species some imperfect fragments of a shell most nearly related to the Leptena
Hardrensis, Phil., but with the striae somewhat finer. The specimens to which I allude are certainly not the
young of the O. crenistria, which has much wider and more unequal striz.

CARBONIFEROUS FOSSILS OF IRELAND. 127

DELTHY RIDA.

The Delthyride or Spirifers (with the exception of Orthis, not then known) were originally formed into
the genus Spirifer by the late Mr. Sowerby, who named them from the spiral appendages which he was the first
to figure and describe. This he did on the supposition that they were “ two spirally-rolled cones,” and as such
he has figured them, both in the Linnean Transactions and Mineral Conchology, without, however, indicating the
manner of their attachment to the shell, or their uses. The turns are so coated with little crystals of caleareous
spar in those figures, that they appear much thicker than they really are, and touching each other; the conse-
quence of which has been, that nearly all the continental geologists have described them as two hollow cones
floating free in the body of the animal. M. Deshayes considered them as the arms of the animal, and mistak-
ing the crystallization represented in Mr. Sowerby’s figure for joints, he describes them as articulated (which
the arms of Brachiopods never are). Almost every author* of the present day considers these appendages as the
arms of the animal. As Ihave been led to hold an entirely opposite view, it may be necessary to enter into some
details of the internal structure of the Spirifers, which I have arrived at by making a great number of sections
of the shells, and from the examination of several silicious casts, the calcareous matrix of which I succeeded in
removing, by the action of dilute hydrochloric acid, so as to display the parts with
great delicacy.

Inthe dorsal, or large valve, we find two short, strong, cardinal, teeth (see fig. 14),
A A, one at each side of the base of the triangular foramen; in order to give the

requisite strength to these teeth, we find them, in all the species, supported by two
thin, shelly plates, which extend from their bases to the beak of the shell, and rest
against the dorsal valve (8 B). These I propose to call the dental lamelle ; it is
their bases which form the two diverging lines we so constantly find on grinding
down or polishing the beak of the large valve of the Spirifers (see fig. 14, lower
ficure), they form the sides of the triangular foramen. In the centre and invariably

longer than these is a smaller septum (Cc).
In the ventral or smaller valve we find no septum, but the cardinal teeth, like those of the Terebratule,
are exceedingly complex, they arise one on each side the beak, by a broad, flattened base, from which they
Fig. 15. Fig. 16. diverge as in the annexed cut (fig. 15) approximating again
An at about the middle of the shell, where they give off a short,
\ blunt process, directed backwards ; they then diverge until
oa i\ they reach the anterior margin of the shell, when they turn
)| backwards, and towards the beak forming a number of spiral
turns, diminishing in size towards the cardinal angles. These
are the bodies considered by most authors as the arms of the
animal, but which I hope to be able to shew, are merely a
modification of that delicate, shelly support, which we find
in the true Terebratule (see fig. 16), for the body of the ani-
mal. In the first place the arms of Brachiopods are analo-
gous to the foot of other bivalves, and therefore take their
origin from the body of the animal, not from the shell. I have
been able to demonstrate that the present organs arise from
the shell, in precisely the same position as the internal sup-
port of the hving Terebratule. Mr. Sowerby describes the appendages of the Spirifere, as “hollow, cartilagi-
nous tubes ;” in this it is possible that he mistook the outer coating of minute crystals for the tube itself, and the

“This was written nearly three years ago; some of the views have been since adopted by others.

128 SYNOPSIS OF THE CHARACTERS OF THE

true shelly support in the middle as the hollow ; I am led to this conclusion from having myself succeeded in
removing this crystalline coating in many species, among others those figured by Mr. Sowerby, and in every in-
stance I have found the true spiral process to be perfectly flat, and not as thick as the thinnest writing paper,
perfectly resembling, in fact, the (in my mind) analogous processes in the living Terebratule. The negative
argument against their being the arms, properly so-called, is, that in no single instance have these organs been
found in any of the Brachiopoda of the newer rocks; even where the impressions of the fleshy arms of Cepha-
lopoda have been preserved, none of the Terebratulide (which we know had those arms) shew them in the
fossil state, but they all exhibit the variously modified, shelly support, preserved in exactly the same manner as
the external shell. It is only in this group that they assume a spiral form. ;

The family Delthyrid@ appear to be divided into the five following natural genera: 1. Spirifera, Sow.,
(fig. 17), composed of those longitudinally-ribbed species, in which the hinge-line is equal to, or exceeds the
width of the shell, the cardinal area with parallel sides, the cardinal teeth of the ventral valve large, spirally
rolled, and having a triangular foramen beneath the beak of the dorsal valve. 2. Martinia, M‘Coy (fig. 18),

Fig. 17.

Fig. 19. Fig. 20. Fig. 21.

ie
or the smooth Spirifers in which the hinge-line is less than the width of the shell, and the cardinal area
triangular. 3. Athyris, M‘Coy (fig. 19), in which there is no vestige of either foramen, cardinal area, or
hinge-line. This remarkable genus is frequently confounded with those shells usually named Terebratula,
in the older rocks, but is distinguished by the large, spiral appendages, which are wanting in the other group.
4. Brachythyris, M‘Coy (fig. 20), in which we find the longitudinally-ribbed surface of Spirifera, united with
the short hinge-line of Martinia. 5. Orthis, Dal. (fig. 21), in which there are no spiral appendages, the hinge-
line and striz frequently spinose (as in Leptena), and the cardinal area common to both valves, and its
sides inclined towards each other at its angles; dorsal valve smallest.

SPIRIFERA. Sow.

Gen. Ch.—Shell transversely elongate ; hinge equalling or exceeding the width of the shell; surface ribbed
longitudinally ; cardinal area with the sides parallel, or nearly so; a triangular foramen beneath the beak of
the dorsal valve; dental lamelle short, divergmg; cardinal teeth of the ventral valve very long, spirally rolled.

This well known genus appears to have three minor or subgeneric types of form; one of them is Spirifera
proper, as above defined; 2. Cyrtia, of Dalman, in which the cardinal area is exceedingly wide, triangular, and
the beak of the dorsal valve not incurved; 3. Fusella, M‘Coy, including those little shells allied to the Spi-
rifera fusiformis and rhomboidea of Phillips, Geol. Yorkshire, having a regular fusiform outline, with a very

wide and hollow cardinal area, the sides of which are parallel.

SPIRIFERA APERTURATA. Schlot. sp.
Terebratula aperturata. Schlot. ?—Spirifer aperturata. Phil. Pal. Fos.
Sp.Ch.—Semicircular, gibbous ; mesial fold large, rounded, sides rounded, cardinal angles mucronate;
sides with coarse, rounded, equal ridges, mesial ridge, and hollow, with fine, sharp, longitudinal ridges, half as

thick as those on the sides.
The Eifel specimens of this shell have more numerous radiating ridges than the Devonian or Trish exam-
ples (which are identical), and have a more marked difference in thickness between the mesial and lateral ribs.

CARBONIFEROUS FOSSILS OF IRELAND. 129

SPIRIFERA ATTENUATA. Sow.

Spirifer attenuatus. Soe. Min. Con.—Spirifera attenuata. Phil. Geol. York.

Sp. Ch.—Convex, width exceeding twice the length, cardinal angles attenuated ; mesial fold rounded,
defined, cardinal area flat, with parallel sides; beaks incurved, but not close; radiating ribs numerous, some-
times simple, sometimes branched.

This is, perhaps, one of the most difficult species to characterize, so numerous are its varieties; the type of
the species is about three times as wide as long, the depth equal to about the length of the smaller valve ; the
mesial ridge and corresponding hollow rounded; the ridge defined on each side by a sulcus deeper than the
rest; the surface covered with exceedingly numerous, thin, branched ribs. But the greater number of specimens
differ in.some particular or other. Thus, many specimens have no mesial elevation, in others the width is
little more than twice the length; the depth varies greatly, and as to the radiating ribs we have every variety,
between those specimens having seventy very thin, branched, ribs, and those possessing but half the number of
thick, rounded, simple, or undivided ribs. With respect to these latter varieties, I should remark, that some
authors have lately separated those with branched, and those with simple ribs, into two distinct species, but it is
not by any means unfrequent to find the ribs on the dorsal valve branched, and those on the ventral valve sim-
ple, in the same specimen; and where a large number of specimens can be compared, the passage from one ex-
treme to the other may in general be traced in the most perfect manner. In all these varieties the cardinal
angles, when perfect, are extended into long, smooth spines. Length one and a quarter inches, width three
inches, depth one inch.

SPIRIFERA BICARINATA. M‘Coy. (PI. XXII fig. 10).

Sp. Ch.—Rhomboidal, width more than twice the length, very gibbous; sides cylindrical; mesial fold
wide, smooth, concave on both valves, bounded on both valves by two large, rounded keels; about twelve
rounded, entire ribs on each side; cardinal area with parallel sides, very wide and hollow.

This curious species is easily recognized by the mesial fold being concave, and bounded by large keels
on both valves. Length eight lines, width one inch six lines.

SPIRIFERA BISULCATA. Sow.
Spirifer bisulcatus. Sow. Min. Con.

Sp. Ch.—Semicircular, gibbous; about ten or twelve strong, rounded, entire ribs on each side of the mesial
furrow, which is strongly defined, round, and prominent, with slightly smaller, dichotomous ribs; cardinal area
narrow, beaks almost in contact; width very little greater than the length.

Although this is found in almost every list of mountain limestone fossils, [have found it exceedingly scarce
in every locality in Ireland, the fossils of which I have had an opportunity of examining, except the lime-
stone of Blacklion near Enniskillen; the specimens most usually seen in Irish collections under this name,
being imperfect individuals of Spirifera attenuata, having their cardinal angles broken off, so that the length and
width may be about equal. Besides having its length and breadth nearly alike, the present species may be dis-
tinguished from the Spirifera attenuata by the small number of its simple, lateral ribs. Won Buch, and most
continental Oryctologists, consider this species as identical with the Spirifer aperturatus of Schlottheim ; but as
Mr. Londsdale has already remarked, the beaks of the Spirifera aperturata are widely separated by an obtusely
triangular, cardinal area, while the present shell has the beaks in contact, and a cardinal area with parallel sides.
Professor Phillips’s figure does not appear to belong to this species, it bears a closer analogy to the Spirifera
disjuncta, and to the next species. Length one inch, width fourteen lines, depth nine lines.

2k

130 SYNOPSIS OF THE CHARACTERS OF THE

SPIRIFERA CALCARATA. Sow.

Spirifer calcaratus. Sow. Geol. Trans.—Spirifera calcarata. Phil. Pal. Fos.

Sp. Ch._—Nearly three times as wide as long, convex; cardinal angles attenuated, smooth; mesial furrow
strongly defined; surface round, with numerous sharp, equal, radiating ridges, rarely branched; those on the
mesial furrow smaller, and less prominent.

This species is very common in the carboniferous slate of nearly every district in Ireland. It resembles
the S. attenuata of the limestone in many points; but is more depressed, has the mesial fold more strongly de-
fined, and has the ridges more equal and sharply marked. Length seven lines, width one inch seven lines.

SprrirERA cHoristiTES. Von Buch.

Choristites mosquensis Sowerbii. isher. Oryct. Mos.

Sp. Ch.—Subquadrangular, gibbous; cardinal area wide, flat; beaks incurved, remote ; mesial fold shal-
low, rounded; ribs numerous, depressed, branched, about nineteen on each side the mesial fold, which has
about ten of the same size and structure as those on the sides. Length slightly exceeding the width.

This species is distinguished from the Spirifera bisulcata by the beaks being so far apart, and by the great
number of its lateral radiations; from the Spirifera attenuata it is distinguished by its length being about equal
to the width. Ido not know that this shell has been before detected in Britain, unless, indeed, Mr. Sowerby’s
Spirifera disjuncta may be looked upon as a variety of it. Professor Phillips’ Spirifera bisulcata is, perhaps,
also nearly allied to it. Spirifera disjuncta of the Devonian rocks is a wider shell. ‘The specimens which I
have referred provisionally to this species have the mesial fold more strongly marked than in the foreign exam-
ples. Length one and a half inches, width two lines less, depth one inch.

SPIRIFERA CLATHRATA. M*‘Coy. (PI. XIX. fig. 9).

Sp. Ch.—Semicireular, gibbous; sides slightly cuspidate, twice as wide as long; mesial lobe narrow,
rounded, prominent; ribs numerous, branched, three or four on the mesial fold, and about sixteen on each side;
whole surface reticulated with very minute, longitudinal, and transverse striz.

This interesting shell might be mistaken for one of the shorter varieties of the S. attenuata, were it not
for the minute reticulation of the surface. Length seven lines, width one inch two lines. Grows very much
larger than the specimen figured, equalling the Spirifera gigantea in size, to which species it is closely allied ;
the reticulation of the surface, however, seems peculiar.

SprrireERA convoLtuTa. Phil.

Spirifera convoluta. Phil. Geol. York.

Sp. Ch.—Fusiform, depressed, width about four times the length; cardinal area concave, striated across ;
surface radiated with numerous, obtuse, rounded, smooth ribs, three of which are elevated to form the mesial

fold.

This species is easily known from all others by its excessive width. Length eleven lines, width four inches.

SPIRIFERA COSTATA. Sow.

Spirifer costatus. Sow. Geol. Trans.

See §. speciosus. Mr. Sowerby’s shell, and some of the Irish carb. slate specimens, have the ribs narrower,
and the intervening spaces wider, than in the Eifel specimens.

CARBONIFEROUS FOSSILS OF IRELAND. 131

SprrireRA Crispa. Sow.
Spirifer crispus. Sov. Sil. Syst.—Delthyris crispus. Dal. Act. Holm.

Sp. Ch.—Semicireular, gibbous; hinge-line equal to the width of the shell; cardinal area large; three or
four large plaits on each side of the mesial ridge; surface crossed by concentric, imbricating lamine of growth.

This beautiful shell is allied to the C. inseulpta, Phil., and S. octoplicata, Sow. Length six lines, width
nine lines.

SPrRIFERA DECEMCosTATA. M‘Coy. (PI. XXII. fig. 9).

Sp. Ch.—Semicireular, gibbous, smooth, twice as wide as long; front rounded; sides suddenly attenuate,
cuspidate ; mesial lobe large, round, projecting, with five large, rounded ribs on each side, leaving a broad space
at the cardinal angles smooth, or only striated transversely.

This species is so very distinct from every other Spirifera with which Iam acquainted, that it would be un-
necessary to point out any particular difference; the whole surface is smooth, except the cuspidate sides, which
are marked with strong lines of growth.

SPIRIFERA DISJUNCTA. Sov.
Spirifer disjunctus. Sow. Geol. Trans.—Spirifer disjuncta. Phil. Pal. Fos.

Sp. Ch.—Semicircular; twice, or twice and a half as wide as long, gibbous; cardinal area broad, flat,
beaks remote; mesial furrow strong; surface with numerous, narrow, radiating ridges.

This species is more gibbous and less transverse than the S. attenuata, and has a much wider cardinal
area. Length one inch, width two inches three lines.

SPIRIFERA EXTENSA. Sov.

Spirifer extensus. Sow. Geol. Trans.

Sp. Ch.—Wiadth five times the length, convex; cardinal area narrow, with parallel sides; cardinal angles
very acute; mesial fold prominent, defined; surface radiated with narrow, rounded, equal ribs.

A few imperfect specimens of this species have occurred; it is allied to the §. convoluta, Phil., but is dis-
tinguished by its more numerous and slender radiating ridges. Length six lines, width two inches six lines.

SpPrRIFERA FuRCATA. M‘Coy. (Pl. XXII. fig. 12).

Sp. Ch.—Semicireular, gibbous; length three-fourths the width; sides rectangular; mesial fold defined,
prominent, rounded, with about six thick, rounded ribs, two of which reach the beak; sides with about five
strong, radiating ridges on each side, near the beak, each of which branches into two or three strong, rounded
ribs, as they approach the margin.

Distinguished from Sp. (Brachythyris) duplicicosta, Phil., by the long hinge-line and cardinal area,
which place it in the present genus as strictly defined, and by the greater thickness and less number of radiat-
ing ribs; and from the S. lava, Portk., by the strongly ridged mesial fold. Length eleven lines, width four-
teen lines, depth six lines.

SPIRIFERA FUSIFORMIS. Sow.
Spirifera fusiformis. Phil. Geol. York.
Sp. Ch.—Transversely elongate; width nearly four times the length; sides rapidly tapering, conical ;

mesial hollow wide, smooth; mesial ridge with three ribs; eight round, smooth ribs on each side the mesial fold ;
it has a wide and greatly hollowed cardinal area, the beaks are much incurved and approximate; the sides

132 SYNOPSIS OF THE CHARACTERS OF THE

diminish rapidly in size from the mesial fold, and are almost perfectly round. Length four lines, width one
inch three lines, depth four lines.

This little species might be regarded as the type of a subgenus, (Fusella, M‘Coy) which might be thus
characterized.

Gen. Ch.—Shell elongate transversely, fusiform; cardinal area wide, much curved; beaks incurved.

This group would embrace these little Spirifers of the mountain limestone, which have a perfectly fusiform
outline, the depth being equal to the length, and the sides cylindrical; the cardinal area is extremely wide in
proportion to their size, and is always hollowed, or much curyed, thus contrasting with the narrow, flat area of
the typical Spirifers, while the strongly curved beaks distinguish them from the Cyrti@. It would include
the S. bicarinata, S. rhomboides, &c. &c.

SPIRIFERA GIGANTEA Sow.
Spirifer giganteus. Sow. Geol. Trans.—Spirifera gigantea. Phil. Pal. Fos.
Sp. Ch.—Transversely elongate; sides cuspidate, mesial fold defined; about twenty-five narrow entire
ribs on each side, crossed by numerous lines of growth.

This large species is not uncommon in some localities in Ireland; it has been confounded by some of the
English geologists with the 8. princeps, from which it differs in its slender and more numerous radiating ridges.

SPIRIFERA GRANDEVA. Phil.
Spirifera grandeva. Phil. Pal. Fos.

Sp. Ch.—Truneato-orbicular, front narrow, sides nearly straight, gibbous; cardinal angles acute, mesial
fold broad, rounded, well defined; about nine or ten large, rounded ribs on each side the mesial fold, on which
there are about five ridges equal in size to those of the sides.

A single specimen of this very rare species has occurred; it is distinguished fromthe S. aperturata by the
ereater size of the ribs on the mesial fold.

SPIRIFERA INORNATA. Sov.
Spirifer inornatus. Sow. Geol. Trans.

Sp. Ch.—Nearly four times as wide as long, convex; surface irregular, smooth, with a few unequal, trans-
verse waves of growth.
A few imperfect fragments of this species have been found.

SPIRIFERA MEGALOBA. Phil.
Spirifera megaloba. Phil. Pal. Fos.

Two or three large, rounded, transversely imbricated ribs belonging to this species have occurred.

SPIRIFERA MESOMALA. Phil.
Spirifera mesomala. Phil. Pal. Fos.

Sp. Ch.—Semicircular, depressed; mesial fold broad, flat, smooth, and sharply defined, about ten narrow,
rounded, equal ribs on each side.

SPIRIFERA MINIMA. Sow.

Anomites acutus. Mart. Pet. Derb,—Spirifer acutus. Flem.—Spirifer minimus. Sow. Min. Con.

Sp. Ch—Semicircular, convex, length two-thirds the width; ribs deep, equal; mesial ridge and furrow
angular; cardinal area small; cardinal angles obtuse; beak of dorsal valve prominent, incurved.

CARBONIFEROUS FOSSILS OF IRELAND. 133

This is one of the smallest species of Spirifera; it is very rare; it appears to be the Anomites acutus of
Martin; so that, following Fleming, we ought, perhaps, to place aeutus as the specific name. Length about

half an inch.

SPIRIFERA OCTOPLICATA. Sow.
Spirifer octoplicatus. Soe. Min. Con.
Sp. Ch.—Trigonal; hinge-line equal to the width of the shell; four large angular plaits on each side the

mesial ridge ; surface smooth.
The nearly smooth surface is the principal distinction between this species and some of the varieties of

the S. erispus. Length six lines, width nine lines.

SprrirerA OrniTHoRHYNCHA. M‘Coy. (Pl. XXI. fig. 2).

Sp. Ch.—Cruciform, a very large, compressed, smooth, mesial ridge on both valves, greatly produced
into a beak in font; sides narrow, cylindrical, with five or six obtuse radiating ridges; cardinal area large
hollow.

When seen in front, the long, central beak, at right angles to the cylindrical sides, gives this shell the
appearance of the Roman letter T., and when viewed laterally, the resemblance to the beak of the little Auk
Alca Alle, has suggested the specific name. Length of central beaked portion, one inch two lines.

SPIRIFERA OSTIOLATA. Schlot.

Spirifer ostiolatus. Schlottheim. Nachtrege.

Sp. Ch.—Suborbicular, gibbous; length three-fourths the width; cardinal angles obtuse, beaks approxi-
mate; cardinal area narrow, with parallel sides; about twelve broad, rounded, entire ridges on each side; me-
sial ridge and hollow broad, shallow, smooth.

In this fine species the surface is minutely granulated in most of the specimens, as noticed by Mr. Lonsdale,
I am not quite sure whether it be due to the mode of preservation. Length one inch three lines, width one
inch six lines.

SPIRIFERA PRINCEPS. M<‘Coy. (Pl. XXI. fig. 1).
Spirifera Princeps. M‘Coy. In Cat. Geol. Soc. Dub.

Sp. Ch.—Semicireular, twice as wide as long, gibbous; numerous furrows from the beak, which increase
in number towards the margin, including between them broad, flattened, branched ribs; front elevated in the
middle, with about five ribs on the rounded mesial elevation, of the same size as those on the sides; hinge-line
equal to the width of the shell, cardinal angles slightly acute, flattened; beaks approximate.

This species agrees with the shorter varieties of Spirifera attenuata in the proportion of length to breadth,
but differs in having but half the number of radiating, branched ribs; while itis distinguished from the Spirifera
bisulcata by its greater width, and by having a greater number of ribs, which are simple in Spirifera bisulcata,
but much branched in the present species, which is also much larger than either. With the Spirifera
striata it has little affinity, being much more tumid, and the mesial fold being round instead of triangular, as
in that species, the character of the ribs also differs entirely. Length three and a-half inches, width six
inches.

SPIRIFERA PULCHELLA. Sow.
Spirifer pulchellus, Sow. Geol. Trans.

Sp. Ch.—Transversely oval, gibbous; beak of the dorsal valve large, incurved; cardinal area triangular;

cardinal angles rounded; two large rounded ribs on each side the mesial furrow, which is narrow and rounded;

surface smooth, or with a few concentric lines of growth.
PAG

134 SYNOPSIS OF THE CHARACTERS OF THE

This little species is not uncommon, in company with the S. crispa, S. speciosa, &e. Length three lines,
width five lines.

SPIRIFERA QUINQUELOBA. M‘Coy. (Pl. XXII. fig. 7).

Sp. Ch.—Ventral valve semicircular, twice as wide as long, with five nearly equal, rounded, distant, ra-
diating ribs, crossed by sharp, regular, concentric lines of erowth.

This species is distinguished from the S. ptychodes, Dal., which has also five lobes, by its greater width
and transverse strie; from the S.crispa of the Silurian rocks (allied to the S. amblyptera, Phil.), by its greater
width and acute cardinal angles; from the S. erispa of the Eifel and Irish carboniferous slate, by the small
number and roundness of its distant, radiating ribs. Length three lines, width six lines.

SPIRIFERA RHOMBOIDEA. Phil.
Spirifera rhomboidea. Phil. Geol. York.

Sp. Ch.—Fusiform, rhomboidal; width exceeding twice the length; depth exceeding the length of the
small valve; mesial fold defined, rounded, bearing six round, smooth, radiating ribs; about twelve rather
larger ribs on each side.

This is not an uncommon species; the long, cylindrical sides render it very striking. Length seven
lines, depth six lines, width one and a quarter inches.

SPIRIFER ROTUNDATA. Sow.
Spirifer rotundatus. Sow. Min. Con.—Spirifera rotundata. Phil. Geol. York.

Sp. Ch.—Transversely oval, depressed ; cardinal area narrow; beaks approximate; about twelve, broad,
flattened (occasionally branched) ribs, on each side the mesial elevation, which is large, rounded, and
smooth.

The width of this species is about once anda half the length, the depth half the width; the lateral radia-
tions are broad, and much flattened, usually branched ; the mesial ridge smooth, rounded, usually with a sulcus
down the middle; the corresponding hollow has obscure ribs, somewhat smaller than those of the sides (I
have seen a few specimens in which both the mesial hollow and ridges had obscure ribs). This very common
species is united by Von Buch to the Spirifera ostiolata, from which, however, it differs very widely. Most of
our English authors have confounded it with the Spirifer pinguis of Sowerby (see Brachythyris pinguis).
It is not the Anomites rotundatus of Martin. Length two inches three lines, width three inches.

SpIRIFERA RuUDIS. Phil.
Spirifera rudis. Phil. Pal. Fos.

A few obscure fragments, resembling Professor Phillips’ figure more than any other species I am acquainted
with, have occurred, but they are too imperfect to furnish a description, nor is any definition of the species
published.

SprriFERA SPECIOSA. Bronn.

Spirifer speciosus alatus. Bronn. Leth. Geog.

Sp. Ch.—Transversely elongated, fusiform, gibbous; sides conical, pointed; cardinal area narrow, with
parallel sides; mesial fold broad, rounded; about ten narrow, rounded, prominent ribs on each side; entire
surface crossed by regular, imbricated, erect, scale-like laminz of growth.

This beautiful shell is abundant in the Eifel, and certain districts in Ireland, I can see nothing to distin-
guish the §. costata of Sowerby from this species.

CARBONIFEROUS FOSSILS OF IRELAND 135

SPIRIFERA STRIATA. Sow.

Anomites striatus. Mart. Pet. Derb.—Spirifer striatus. Sow. Min. Con.

Sp. Ch.—Semicircular, depressed; cardinal angles acute; mesial fold angular, produced in front; cardinal
area large, hollow, with parallel sides; about fourteen sharp, unequal sulci on the mesial fold, and thirty-seven
on each side.

Next to Spirifera princeps, M‘Coy, and S. giganteus, Sow., this is the largest of the known Spirifers, fre-
quently attaining the width of four inches, or even more. The surface is much depressed; the mesial fold
strongly defined, angular, and forming a triangular projection in front; the sides are acutely angular; car-
dinal area large, and much curved; the beak incurved, but small; the stria are exceedingly numerous, sharply
defined, narrow, and rather unequal. This shell is very well known on the Continent, as the species in which
Mr. Sowerby first discovered the spiral appendages, a part of which he figured, rather larger than nature, in the
twelfth volume of the Transactions of the Linnzan Society. Length three inches, width four inches and a half,
depth one inch and a half.

SPIRIFERA TRANSIENS. J/‘Coy. (Pl. XIX. fig. 14).

Sp. Ch.—Triangular, or rhomboidal, including the beak, twice as wide as long, gibbous; mesial fold very
large, prominent, rounded, undefined, producing a very deep sinus in the front margin; sides radiated with
about ten or twelve large, thick, rounded ribs, equal, or irregularly duplicate ; mesial fold with about six or
seven ribs, equal in size to those of the sides; cardinal angles acute; cardinal area low, triangular.

This species is most nearly allied to the S. grandeva of the Devonian rocks, but is distinguished by its
very large, undefined mesial fold, and more tumid sides; from S. biseuleata and S. attenuata it differs in its
very large, undefined, mesial fold, and the smaller number and greater size of its radiating ribs, and most im-
portantly by the triangular cardinal area, as in Cyrtia. Length one inch seven lines, width two inches six
lines. Young specimens are not so wide in proportion to the length.

SPIRIFERA TRIGONALIS. Sov.
Anomites trigonalis. Martin, Pet. Derb.—Spirifer trigonalis. Sow. Min. Con.

Sp. Ch.—Gibbous; margin semicircular; cardinal angles acute; hinge-lne broad, flat; from twenty
to thirty strong, radiating ribs, three of which are elevated to form the mesial ridge; the ribs of the mesial fold
usually divide into two or three as they approach the margin, those of the sides always entire.

They are, perhaps, two species confounded under the name of Spirifera trigonalis, the one is usually about
one inch and a half long, and two inches and a half wide; tumid, and with a semicircular outline, the mesial
fold forming a square sinus in the margin, a deep hollow in the dorsal valve, but from being flattened on the
top, is scarcely raised above the surface of the ventral valve; about twelve or fourteen strong, rounded ribs on
each side the mesial fold, and three on the mesial fold; the centre one of which usually divides obscurely into
three, the others into two; the cardinal area very broad, slightly curved. This is the shell figured and described
in the Mineral Conchology. The other comes nearer to the shell figured by Martin, it is much smaller,
rarely exceeding three-quarters of an inch in length, and one inch anda quarter in width; only seven angular
ribs on each side the mesial fold; the mesial elevation, instead of being flattened on the top, forming a small,
square sinus in the margin, and being confounded with the surface of the ventral valve is acutely angular,
forms an exceedingly deep, triangular sinus in the margin, and rises very prominently from the ventral valve;
the plaits on the mesial elevation of the first shell are of an equal size with those on the sides; but in the other
they are much smaller and more obscure. Both varieties are common in certain localities.

136 SYNOPSIS OF THE CHARACTERS OF THE

SprrirerA Uri. Flem.
Spirifera Urii. Fem. Brit. Anim.—Atrypa unguiculus. Sow. Geol. Trans.—Spirifera unguiculus. Phil. Pal. Fos.
Sp. Ch.—Hemispherical; dorsal valve very gibbous; beak large, pointed; ventral valve nearly flat; sur-
face smooth; both valves with a narrow, linear, mesial sulcus.

This curious little shell is subject to much variation in its characters, but is at all times easily recognized
by its peculiar form, and the deep, narrow sulcus in both valves.

Cyrtia. Dalman.
Gen. Ch.—Cardinal area very wide, triangular; beak of the dorsal valve pointed, not incurved; mesial
fold usually smooth.
This group is admissible only as a subgenus of Spirifera, from which it is distinguished by its cardinal area
being triangular, and the beak of the dorsal valve very slightly incurved, characters, however, which vary very
much even in the same species.

Cyrtia cuspipata. Mart. sp.
Anomites cuspidatus. Martin, Pet. Derb.—Spirifer cuspidatus. Sow. Min. Con.—Spirifera cuspidata. Phil. Geol. York.

Sp. Ch.—Pyramidal; cardinal area very large, flat, triangular, forming, in old specimens, an acute angle at
the beak of the dorsal valve; mesial ridge and hollow broad, rounded, smooth; fourteen rounded, entire ribs
on each side the mesial fold.

This very well known shell was first noticed by Mr. Martin (in the Linnean Transactions, vol. iv. p. 4),
who considered it to form a distinct division of the group now called Spirifers. It is placed by Professor Phil-
lips at the head of his division Cuspidate, which is nearly equivalent to Dalman’s genus, Cyrtia, which I have
adopted, considering it, however, as only a subgenus of Spirifera, its characters bemg obviously subordi-
nate to those of that genus, and of less importance than any of generic distinction in this family. The cardinal
area of the present shell varies with the age of the animal: in young individuals its height is less than the width
of the hinge-line; im old it considerably exceeds it. The mesial fold is usually broad, rounded, and smooth,
but specimens are not rare in which the mesial elevation is flattened, and divided in the centre by a sulcus, as
in Cyrtia distans ; and I have also seen specimens in which the mesial hollow was obscurely ribbed, as in that
species. Length two inches, width the same.

Cyrtia pIsTANS. Sow. sp.
Spirifer distans. Soz. Min. Con.

Sp. Ch.—Rhomboidal, length two-thirds the width, depth equal to the length of the smaller valve; about
fourteen rounded, entire ribs on each side the mesial ridge, which is wide, smooth, and divided by a sulcus in
the middle; the corresponding hollow on the dorsal valve contains about eight longitudinal ribs.

The ribs in the mesial hollow of this species are somewhat smaller than those on the sides; the mesial ele-
vation is without plaits; the cardinal area very wide, curved; foramen small. Von Buch considers this species
as identical with the Spirifer speciosus micropterus of Goldfuss. It differs, however, in having ribs in the
mesial hollow, its more numerous plaits, and the greater space between the beaks. Length one and a quarter
inches.

Cyrtia porsata. M‘Coy. (Pl. XXII fig. 14).

Sp. Ch.—Subrhomboidal, nearly twice as wide as long; dorsal and ventral valves evenly convex; beak
of dorsal valve large, straight; cardinal area very large, triangular, slightly concave; mesial fold indistinct, or
none; surface coarsely and regularly striated longitudinally.

This remarkable species has nearly the form of the Strigocephalus dorsatus, Gold., but is a true Cyrtia;

CARBONIFEROUS FOSSILS OF IRELAND. 137

like the C. senilis, Phil., the mesial fold is obsolete; the dorsal and ventral valves are evenly convex; cardinal
angles acute in the young, rounded in the old shells; the strizw are coarse, round, and equal. Length two
inches four lines, width two inches ten lines; height of cardinal area one inch three lines.

Cyrtra Laminosa. M‘Coy. (Pl. XXI. fig. 4).

Sp. Ch.—Semicircular, about twice as wide as long; cardinal area wide, triangular; surface with about
seven, prominent, angular, radiating ribs on each side the mesial fold; mesial fold deep, wide; entire shell
crossed by close, waving, erect lamine.

This most beautiful Spirifer is distinguished from the other species by the singular, scale-like sculptur-
ing of the surface, from which it derives its name. Length seven lines, width one inch three lines.

Cyrtia Lincurrera. J‘ Coy.
Spirifera ostiolata. Phil. Pal. Fos, (omit Synonymes).

Sp. Ch.—Subrhomboidal, gibbous; cardinal area large, triangular, concave; mesial fold wide, rounded,
well defined, in old shells produced in front into a tongue-shaped process, without ribs on either valve; ten
rounded, smooth ribs on each side the mesial fold.

The shell to which J have given this name appears to me identical with that figured by Professor Phillips,
from the Devonian rocks, considered by him as the Spirifera ostiolata of Bronn and Schlottheim; that shell

has, however, a narrow cardinal area, with parallel sides, and the beaks incurved, approximate; the present
species has, on the contrary, a very wide triangular area, and the beak of the dorsal valve is not incurved;
there are also several minute distinctions between the species; I have given, however, the most striking
points. The lateral ribs are rounded and smooth, about ten or twelve or each side the mesial fold. I have
a very singular specimen from the Kildare limestone, which has twelve ribs on one side the mesial ridge, and
but six on the other; the mesial fold is very prominent, and rounded, the surface, particularly in old shells,
is marked by irregular, transverse lines of equal growth. Length one inch, width one and a quarter inches.

Cyrtia Mesoconta. M‘Coy. (PI. XXII fig. 13).

Sp. Ch.—Semicircular, gibbous; surface smooth; cardinal area wide, concave, triangular; cardinal angles
acute; mesial ridge very prominent, angular, both it and the angular mesial furrow without mbs; eight or
nine strong, rounded, equal ribs on each side the mesial fold.

This species is allied to the Spirifer distans, Sow., and the S. ostiolata, Phil., but is distinguished from
both by the very prominent, angular, mesial fold; §. distans has also the mesial hollow ribbed, while it is
smooth in the present species. Length one inch, width one inch five lines.

CyrTIA NUDA. Sow. sp.
Spirifer nudus. Sow. Geol. Trans.—Spirifera nuda. Phil. Pal. Foss.
Sp.Ch.—Subrhomboidal, gibbous; ventral valve semicircular, width twice its length; cardinal angles
obtusely rounded; cardinal area wide, curved, triangular; mesial fold wide, rounded; one or two obtusely
rounded ridges on each side; surface with obsolete lines of growth.
This obscurely marked species is in length seven lines, width ten lines.

Cyrt1a Semicircunaris. Phil. sp.
Spirifera semicircularis. Phil. Geol. York.
Sp. Ch.—Front semicircular, width double the length; cardinal area variable in width; about four smooth,
radiated ribs are raised with the mesial fold, and there are about fourteen on each side of it.

This shell is allied to the S. distans, but is at once distinguished by the ribs on the mesial elevation. This
2M

138 SYNOPSIS OF THE CHARACTERS OF THE

is one of those very interesting forms which, from being aberrant in their characters, form the passage from one
group to another, being, in fact, a connecting link between the two. The existence of those links in nature
has been frequently urged by short-sighted observers as a reason for uniting the groups so connected. We
should always, however, bear in mind that no group can be considered natural or perfect which does not ex-
hibit forms, partaking in some measure of the characters of the allied groups, and thus shading, as it were, the
one into the other. When such links are wanting, we may rest assured that they are either extinct or as yet
undiscovered; for, wherever our knowledge of species is extensive, we invariably find them forming a continu-
ous and unbroken chain of affinity, harmoniously blending one into the other by the most insensible gradations,
yet, nevertheless, presenting at certain points such remarkable types of form or structure as to deserve a generic
or sectional name, although each point or type may be shewn to pass insensibly into the next, so much so, that
those species which connect the two groups are frequently of such an intermediate character that it may
be difficult to say to which of them it really belongs*.

The present species possesses the triangular cardinal area of the genus Cyrtia, but the beak of the dorsal
valve is slightly incurved, the mesial fold is suleated, and altogether the characters of the species shew a decided
tendency to return again to the more ordinary form of the typical Spirifers, which it enters by means of those
small fusiform shells forming the subgenus Fusella, M‘Coy, in which the cardinal area, though wide and curved,
has parallel edges; this latter group passes into the true Spirifers by means of the Fusella fusiformis on the one
hand, and Spirifera speciosa, and such like shells, on the other. Length one inch, width one inch eight lines.

Cyrira seniuis. Pil. sp.
Spirifera senilis. Phil. Geol. York.

Sp. Ch.—Semicircular, regular, gibbous; ventral valve convex; cardinal area triangular, curved, three
times as wide as high, strongly striated transversely ; surface with radiating striz, and large, obtuse, irregular,
concentric wrinkles.

This very curious shell is among the rarest Brachiopoda of the carb. series; the shell is very thin, as‘ in
Anomia, and the irregular surface also gives it a very peculiar aspect. Length two inches, width two inches
nine lines.

Cyrtia smmpLex. Phil. sp.
Spirifera simplex. Phil. Pal. Fos.

Sp. Ch.—Dorsal valve pyramidal, acute; cardinal area very large, triangular, marked with decussating
striz; ventral valve convex; mesial ridge and hollow rounded, obtuse; surface entirely smooth, without ribs.

This shell is closely allied to the C. euspidata, but is well distinguished by the want of lateral, radiating
ribs. Length one inch six lines; width one inch eight lines.

Cyrrta susconica. Mart. sp.

©. Anomites subconicus. Mart. Pet. Derb.—Spirifer subconicus. Sow. Geol. Trans.—Spirifera subconica. Phil. Pal.
Fos.

A few fracments, possibly of this species, have occurred; it resembles the C. euspidata in miniature, but
g P J Pp Pp
with only five ribs on each side of the mesial fold.

* A remarkable instance of the mischief produced by considering all naturally-connected groups as one, may be seen
in the family Unionide, or fresh water mussels; in this family the species are exceedingly numerous, and consequently
the affinities very perfect; some of the best American and European naturalists, who have devoted years to the
study of these shells alone, considered it to be divided into upwards of twenty genera, all of them distinguished by
marked peculiarities, either in the animals or the shells, but, of course, connected by aberrant species; this perfection,

CARBONIFEROUS FOSSILS OF IRELAND. 139

Martinia. M'‘Coy.

Gen. Ch—Hinge-line shorter than the width of the shell; dorsal edges of the cardinal area obtusely
rounded; surface smooth; spiral appendages small.

The short-hinged, smooth Spirifers, were distinguished long ago by that excellent artist and friend of Mineral
Conchology, Mr. William Martin, and placed by him im a separate division from the long-hinged, ribbed species ;
they were afterwards confounded together by the late Mr. Sowerby, under the general name of Spirifer, in the
Mineral Conchology; they were then separated again by Professor Phillips, in his admirable Geology of York-
shire, and form the fourth division of his genus Spirifera ; and more recently Von Buch, in his memoir on the
genus Delthyris, forms of them his second division of the Spirifere, but
hitherto no author has named, or fully characterized, this most natural genus.
The spiral appendages, instead of filling nearly the whole shell, as in the true
Spirifers, are so small as only to occupy the upper or rostral half of it (fig.
22). Thus furnished with internal as well as external characters, I have no
hesitation in keeping those as a distinct genus of the great family of Spirifers,
and dedicating it to the author of the Petrificata Derbiensia, to whom we owe
the first figures and descriptions of the more abundant species. Nearly all
the species of this genus, and some of Athyris, are united by foreign Palwontologists under the name Spirifer
levigatus. 1 would not have noticed this were it not that some recent British writers have done the same. I
agree perfectly with Professor Phillips, who has described most of them, in thinking them distinct.

MartTINIA DECORA. Phil. sp.
Spirifera decora. Phil. Geol. York.

Sp. Ch.—Orbicular, convex, smooth; beak of the dorsal valve prominent; cardinal area short, triangular ;
mesial ridge obscure, divided by a longitudinal sulcus.

This is a rare species, approaching very closely in its character to some varieties of the M. symmetrica.
Length one inch six lines, width one inch five lnes.

MartriniaA ELLIPTICA. Phil. sp.
Spirifera elliptica. Phil. Geol. York.
Sp. Ch.—Transversely elliptical; mesial fold wide, flattened, scarcely perceptible, except at the margin ;

surface with very fine radiating striz, decussated near the beak by fine, concentric wrinkles; width nearly
double the length.

This is a very pretty shell, but not common any where; the radiating striz, though constant, are scarcely
perceptible; the concentric markings vanish towards the margin, and become nearly obsolete in old shells.
The beak and cardinal area rather large. Length one inch five lines, width two inches three lines.

Martini GLABRA. Mart. sp.
Anomites glaber. Martin, Pet. Derb.—Spirifer glaber. Sow. Min. Con.—Spirifera glabra. Phil. Geol. York (pars).

Sp. Ch.—Transversely oval; much wider than long, depressed, sharp edged; mesial fold very wide and
prominent; cardinal area variable; surface smooth.

This species is hable to much variation in the proportion of length to breadth; the depth and cardinal
area also vary occasionally, but it is never so rounded in outline, so deep, or with so large a cardinal area, as

however, inclined a distinguished writer to include them all in one genus, and a recent author has gone so far as to con-
sider them all as varieties of one species.

140 SYNOPSIS OF THE CHARACTERS OF THE

either the Spirifera oblata or Spirifera obtusa, with both of which authors have confounded it. Mr. Sowerby
lays stress on the mesial elevation being flattened in the middle; it is, however, very frequently rounded, but is
always very wide and undefined, in which it differs from the next species. Length one inch six lines, width
two inches six lines.

MartiIntA MESOLOBA. Phil. sp.
Spirifera mesoloba. Phil. Geol. York.

Sp. Ch.—Orbicular, depressed; mesial fold round, prominent, sharply defined on both valves; surface
smooth, slightly imbricated; cardinal area very short, triangular.

This species is nearly allied to the preceding, but when once seen will run no risk of being confounded
with it, or indeed with any other fossil I know. In outline it is nearly circular; the valves are smooth, de-
pressed, and sharp-edged; the beaks and cardinal area small; the mesial fold is very peculiar, it is narrow,
rounded abruptly from the depressed surface of the ventral, or smaller valve; it is bounded on either side by an
impressed line, which renders it distinct up to the beak. Professor Phillips’ figure is a very good one, and
shews the character of the mesial fold extremely well. The slightly imbricated lines of growth scarcely diminish
the smoothness of the surface. Length one inch, width one inch two lines.

Martini OBLATA. Sow. sp.
Spirifer oblatus. Sow. Min. Con.—Spirifera glabra. Phil. Geol. York. (pars).

Sp. Ch.—Gibbous, obovate, smooth ; mesial elevation square ; seldom distinct more than half way to the beak.

The depth of this species exceeds half the width; in young individuals there is no mesial elevation, or it
is but slightly marked on the edge of the shell, in old specimens it rarely extends within half the distance be-
tween the front and the beak; in finely-preserved specimens there are traces of very obscure, lateral radiations
towards the margin. It is a local species in Ireland, but where it occurs it is usually very common. Length
two inches, width two inches five lines.

MArtTINIA OBTUSA. Sow. Sp.
Spirifer obtusa. Sow. Min. Con.

Sp. Ch.—Transversely oval, very gibbous; depth half the width; sides tumid; mesial furrow narrow,
rounded, forming a very deep sinus in front; beak of the dorsal valve, and cardinal area large, surface smooth.

This species is thought by many authors to be identical with the Spirifer glaber of the Mineral Conchology.
It appears to me, however, to be distinguished, as Mr. Sowerby observes, by the greater size of the beak of the
large valve, and by the greater depth of the sinus in the front, to which I might add, that the mesial ridge is
much narrower than in the former species, that the width is never so great in proportion to the length, and the
sides, which in Spirifera glabra are always more or less depressed, are in the present shell remarkably
tumid, or gibbous. Length one inch five lines, width one inch nine lines.

MarrIniA PHALANA. Phil. sp.
Spirifera phalena. Phil. Pal. Fos.

Sp. Ch.—Twice as wide as long; beaks very prominent; mesial hollow very wide, rounded, bounded by
two prominent ridges; surface marked with small, rounded, concentric ridges. Length six lines, width one inch
five lines.

MARTINIA PLEBEIA. Sow. SP.
Atrypa plebeia. Sow. Geol. Trans.—Spirifera plebeia. Phil. Pal. Fos.

Sp. Ch.—Orbicular, subrhomboidal, very gibbous; front produced into a tongue-shaped elevation; mesial
ridge wide, indistinct on the ventral valve; beaks small, approximate ; surface smooth.

CARBONIFEROUS FOSSILS OF IRELAND. 141

This is a very small species, rarely attaining three-quarters of an inch in length; it has been taken for the
young of Martinia glabra, but is distinguished by its produced front, the smallness of its beaks, and the want
of the mesial sulcus in the larger valve. Mr. Sowerby’s figure shews no cardinal area, but the shell, which I be-
lieve to be identical, as well as Professor Phillips’s, has a distinct one resembling that of the M. obtusa. Length
eight lines, width nine lines.

Martinia proTensA. Phil. sp.
Spirifera protensa. Phil. Pal. Foss.

The few imperfect specimens which I have referred to this species, appear to me to differ from the S.
obtusa, Sow., only in the stronger striation of the cardinal area, a character which depends very muchon the
state of preservation of the shell. I have not observed the radiated surface.

Martini RHOMBorpALIS. MM‘Coy. (Pl. XXII. fig. 11).

Sp. Ch—Rhomboidal, gibbous, length and width equal; cardinal angles rounded; cardinal area very
small, triangular; beaks small, incurved; mesial fold very prominent, narrow, rounded; mesial sulcus deep;
sinus in the margin large, linguiform; surface radiated with numerous, obtusely-rounded, nearly obsolete
ridges.

This species is allied to the 8. protensa, Phil., from which it differs in the length being equal to the width,
and in the very small size of the cardinal area; from the 4. plebeia, Sow., it differs in the great size of the me-
sial fold, and in the radiated surface. Length eight lines, width seven and a half lines, depth six lines.

MarTINIA STRIGOCEPHALOIDES. J/‘Coy. (Pl. XXII. fig. 8).

Sp. Ch—Suborbicular, gibbous; dorsal valve produced into a lengthened, acute beak; cardinal area nar-
row, acute, angular; no mesial fold; surface marked with regular, concentric lines.

This remarkable shell seems to conduct to the Pentamere by means of Strigocephalus, the external form of
which it exactly assumes, the gradation being rendered perfect by the present shell, on the one hand, and by Pro-
fessor Phillips’s Strigocephalus brevirostris on the other, so like, indeed, are the two shells, that were it not that
the Devonian shell has a smooth surface, and this a concentrically lined one, they might be taken for the same
species. Professor Phillips’s shell, however, has the same internal structure as the Strig. Burtoni, it, therefore,
belongs to the same genus, while my species has the internal structure of the group in which I have placed it.
As this species, from its external characters, appears to form the passage from the complex Deltheride or true
Spirifers to the more simply formed Pentameride of the older rocks, it may be interesting to detail, as far as
I know, its internalanatomy. The dorsal or beaked valve exhibits, at about one-third of its length from the beak,

Fig. 23. the cicatrices of the upper pair of adductor muscles; these are remarkably small, of a lengthened,
4 narrow, oval figure, the depth of each equal to about its own diameter ; they are separated from each
hs, other by ashort, thin, shelly septum, which doesnot extend farther from thebeak than the muscles
\; which it separates. In the annexed cut (fig. 23) I have figured those parts of the natural size, toge-
''// ther with the palleal impression, or attachment of the mantle of the animal. The ventral or smaller
“/ valve has its beak divided by a thin, shelly septum, which, extending a short way towards the

margin, serves to separate the origin of the upper pair of adductor muscles; the cicatrices produced by the

origin of those muscles in the ventral valve are much smaller, even than the origin of those in the dorsal valve ;
they are of the same lengthened shape, but each terminated at the end nearest the beak by a small, deep fora-
men, which serves for the insertion of the principal tendon; they form little, sharp tubercles on the cast. The
spiral appendages arise each from a broad, flattened, triangular process, their bases being placed so as to diverge

ZN.

142 SYNOPSIS OF THE CHARACTERS OF THE

from the beak. The appendage at the right side curves boldly forwards, outwards, and towards the right side,

Fig. 24. again curving inwards at about the middle of the shell, at which point it gives off a short, blunt
process, directed backwards, or towards the cavity of the shell; this is, probably, the principal
fulcrum for the base of the true arms of the animal; from this point it again assumes its former
direction, until it reaches the front margin of the valve, where it turns inwards and backwards,
following the curve of the dorsal valve for about two-thirds the length of the shell, where it
again bends forwards, and a little to the nght of the first turn, thus forming the first, or basal vo-
lution of the spire, which it forms by repeating those curves about eleven times, gradually
becoming more attenuated as it approaches the apex, which is obtuse. The appendage of the
left side is similar in all things, but takes, of course, an opposite direction. In the annexed cut
(fig. 24) I have sketched one of those appendages free from the shell; a represents the broad,
flattened process, by which it is attached to the beak of the ventral or smaller valve, B the
short, obtuse process mentioned above ; when in their natural situation in the shell, as indicated by the dotted
lines (fig. 25), the internal surfaces of the broad bases of attachment embrace firmly the external surfaces of the

Fig. 25. cardinal teeth of the dorsal valve. From the peculiar curves just described at the origin of those
appendages, it will be seen a considerable space results between them, beneath the beaks; this
space affords room for the free action of the two upper pair of muscles for closing the valves.
For the better understanding the relative position of those parts, I subjoin a profile view of the
present species (fig. 25), in which a 4 represent the origin of the superior adductors; B B, the ori-
gin of the superior adductors in the ventral valve; c, one of the cardinal teeth of the dorsal valve ;

D, spiral appendage. Length one inch, width ten lines.

Martinia SyMuetrica. Phil. sp.
Spirifera symmetrica. Phzl. Geol. York.

Sp. Ch.—Quadrate or subpentagonal, very gibbous, smooth; mesial ridge not defined on the small valve;
divided by a sulcus in the middle.

This species is remarkable for its regular rhomboidal form, and divided mesial furrow, the furrow passes
insensibly into the sides of the shell on the small or ventral valve, but is very well defined on the larger one.
The surface is quite smooth, the beaks and cardinal area moderate; the length and width about equal; depth
two-thirds the width. Length one inch nine lines.

Reticutaria. M‘Coy.

Gen. Ch.—Hinge-line shorter than the width of the shell; cardinal area triangular; cardinal angles very
obtusely rounded ; mesial fold very slightly raised, or none; surface ornamented with either fine longitudinal
or transverse striz, or most usually reticulated by both; dental lamelle perfectly parallel.

This beautiful little group includes all those Spirifers analogous to the S. imbricata, S. lineata, S. micro-
gemma, S. reticulata, 8. decussata, &c., having a reticulated or striated surface combined with the general
form and cardinal area of Martinia, M‘Coy, in which genus I formerly placed them, although they obviously
» formed a very marked group, distinguished by its small size, reticulated or striated surface, and very remarka-
bly by the entire absence of the mesial fold in most of the species (in the one or two species which possess a
trace of the mesial fold, it is very slightly elevated). But the internal structure which I have recently seen in
three of the species, presents a very distinct and important character ; the dental lamellz, stead of converging
towards the beak, as in all the other forms of Spirifer, are in those perfectly parallel to each other and to the
central septum, in their whole length, thus confirming by a very interesting internal peculiarity, the easily
recognizable external characters. The genus is carboniferous and Devonian.

CARBONIFEROUS FOSSILS OF IRELAND. 143

RETICULARIA IMBRICATA. Sow. sp.

Terebratula imbricata. Sow. Min. Con.—Spirifera imbricata. Phil. Geol. York.

Sp. Ch.—Transversely oval; strong, obtuse, radiating stria, interrupted by broad, thick, imbricating
lamella; no mesial fold.

This is distinguished from the M. lineata by its thick, radiating strie, and the distance between and
small number of the transverse striae, which, in the present shell, form between them about ten or eleven thick,
imbricated, concentric lamin, each about a line in breadth. Length one inch, width one inch four lines;

usually found in company with the Reticularia lineata.

RETICULARIA LINEATA. Mart. sp.
Anomites lineatus. Martin, Pet. Derb.—Terebratula lineata. Sow. Min. Con.—Spirifera lineata. Phil. Geol. York.

Sp. Ch.—Transversely oval, convex; no mesial fold; surface with close, imbricated, transverse lines.
This very elegant species abounds in the limestone of Little Island, Cork, but is not very common any
where else. It has been figured and described by Sowerby as a Terebratula, not having found the spiral
appendages in it. The beaks and cardinal area are very small; the concentric lines are very numerous and
regular; the two cardinal teeth of the ventral valve are thin, narrow, their bases slightly converging towards
Fig. 26. the beak; those of the dorsal valve are broader and thicker; the cicatrices of the upper pair
of muscles in the ventral valve form two small, deep, oval cavities (elevations in the cast) ;
their long diameters parallel to each other, and directed towards the beak, from which
) they are about their own length distant; the cicatrices of the similar pair of muscles, in the
dorsal valve, are confluent, forming one round, undivided cavity, distant twice its length
from the hinge-line (see fig. 26; A a, origin of upper pair of muscles in ventral valve; B,

origin of upper pair in dorsal valve). Length nine lines, width one inch.

RETICULARIA MICROGEMMA. PAil. SP.

Spirifera microgemma. Phil. Pal. Fos.

Sp. Ch.—Orbicular, gibbous; mesial fold rounded, prominent; beak of the dorsal valve large, tumid; very
fine, radiating striz, and numerous imbricating lamine of growth, the edges of which, when crossed by the ra-
diating striz, are ornamented with minute, rounded tubercles.

This is known from the Reticularia imbricata by the prominent mesial fold; the greater number of the
transverse lamella, the delicacy of the radiating strie, and the little tubercles at the intersection of the lines;
from Reticularia reticulata it is distinguished by its prominent, undefined, mesial elevation, its flattened la-
minz of growth, and its tubercles. Length eight lines, width ten lines.

RETICULARIA RETICULATA. M‘Coy. (Pl. XIX. fig. 15).

Sp. Ch.—Transversely oval; about thirty round, undulating, concentric wrinkles, decussated by exceed-
ingly fine, close, radiating strie; a faint, but defined mesial fold.

This beautiful little species is at once distinguished from the R. imbricata, Phil., by all its markings being
infinitely smaller, and more delicate; the transverse lamin, instead of being broad and flat as in that species,
are very narrow, rounded, and flexuous, and are fully three times the number in the present shell; the
radiating striz are in proportion finer and more numerous. The mesial elevation, though nearly as flat as the
rest of the shell, is defined on each side by a sharp, impressed line; the mesial hollow is deep and also defined
by two obtuse ridges extending to the beak. Length eight lines, width eleven lines.

144 SYNOPSIS OF THE CHARACTERS OF THE

RETICULARIA STRIATELLA. M'‘Coy. (PI. XIX. fig. 13).

Sp. Ch.—Transversely oval, or, including the beak, subrhomboidal, gibbous; front very slightly elevated ;
surface radiated with numerous, fine, close, rounded striz.

The specimen figured of this pretty little shell shews the remarkable parallelism of the dental lamine so
characteristic of the subgenus Reticularia, M‘Coy, it also has the same general form, small size, and absence of
a distinct mesial fold, as in the other species of that very definite little group; the longitudinal striz are very
numerous, fine, and equal. Length six lines, width eight lines.

Bracuytuyris. MM Coy.

Gen. Ch.—Hinge-line shorter than the width of the shell; cardial area small, curved, triangular; surface
ribbed longitudinally.

The species which I bring together under this name, form a very remarkable little group, possessing the
short hinge-line, and triangular area of the genus Martinia, M‘Coy, with the ribbed surface of the true Spirifers.
Holding characters which are essentially intermediate between the more positive distinctions of the more
typical groups, it could scarcely be supposed, that the characters of the genus should be so constant as they
appear to be. Professor Phillips has observed the strong affinity which exists among the species, by making
of them his third division Radiate, of his great group Spirifera. Some of this genus, as Spirifera exarata,
Fleming, and Brachythyris planicostata, M‘Coy, possess the singular peculiarity of their large valve being found
in great quantities separated from the smaller; from which I would infer, that the cardinal teeth of this genus
must be either much smaller or weaker than any other of the family, but I have not ascertained the fact. With
the exception of the two species just mentioned, they are all scarce shells, but found occasionally im all parts of
the carboniferous series, from the millstone grit to the yellow sandstone, inclusive.

BracuytuHyris Dupticicosta. Phil. sp.
Spirifera duplicicosta. Phil. Geol. York.

Sp. Ch.—Transversely oval, depressed; mesial fold angular; about seven ribs on each side the mesial fold,
each of which, at one-third its length from the beak, divides into three others.

This species is rendered remarkable by the regularity with which the ribs branch as they approach
the margin; the mesial fold is angular, very prominent at the margin, usually bearing three ribs near the beak,
which, by their subdivision, form nine as they reach the front. The width exceeds the length by about one-
third, the depth is only equal to half the length of the small valve. Length one inch.

BRACHYTHYRIS EXARATA. lem. Sp.
Spirifer exaratus. Jem. Brit. Anim.

Sp. Ch.—Transversely obovate, cardinal area exceedingly short ; about six very broad, flat ribs on each
side the mesial fold, which is flattened, but distinctly defined, and has usually three obscure ribs; length three-
fourths the width.

I believe Dr. Fleming, the author of the highly useful History of British Animals, is the only writer who
has noticed this remarkable fossil, and Iam not aware that there is any figure of it in existence. It resembles
Spirifera rotundata in general size and shape, but is distinguished by its very short cardinal area, which is, in
fact, almost an equilateral triangle, its length very little exceeding its width. It is curious that this shell, in

common with the Brachythyris planicostata, M‘Coy, is usually found without its ventral valve. Length one
and a half inches, width two inches.

CARBONIFEROUS FOSSILS OF IRELAND. 145

BRACHYTHYRIS HEMIsPHARICA. M‘Coy. (Pl. XIX. fig. 10).
Sp.Ch.—Orbicular; dorsal valve hemispherical; ventral valve flat, slightly convex towards the beak; car-
dinal area an equilateral triangle; mesial fold broad, flat; about ten broad, flat, entire ribs on each side.
The only species this at all resembles is the 8. planata, Phil., from which it is easily distinguished by the
peculiar proportions of the cardinal area and dorsal valve. In some specimens the mesial fold is smooth, in
others obscurely divided by two or three lines, but in all the specimens it is perfectly flat, and not raised above

the surface. Length one inch, width the same.

BRACHYTHYRIS INTEGRICOSTA. Phil. sp.

Spirifera integricosta. Phil. Geol. York.

Sp. Ch.—Transversely oval, gibbous, mesial fold, defined on each side by a furrow deeper than the rest;
ribs very prominent, rounded, entire; beaks closely approximate. There are about ten very prominent, round
ribs on each side the mesial elevation, which latter is prominent, well defined, and formed by the elevation of
three of the ribs, slightly flattened on their summits. The beaks are nearly in contact, the cardinal area con-
sequently narrow, much curved. I have seen fragments of a species closely allied to this, but having only
half the number of lateral radiations, the spaces between them equal to their breadth, and the cardinal area
much shorter. The B. integricosta usually measures one and a-quarter inches in length, and one and a-half in

breadth; depth three-fourths of an inch.

BRACHYTHYRIS LINGUIFERA. Phil. sp.
Spirifera linguifera. Phil. Geol. York.

Sp. Ch.—Rotundato-quadrate, gibbous; mesial fold very prominent, rounded, smooth; about ten broad,
faint ribs on each side near the margin; length nearly equal to, or slightly exceeding, the width; depth equal
to the length of the ventral valve.

This is the most aberrant species of the genus, leading to Martinia, or the smooth Spirifers; we accord-
ingly find the lateral ribs exceedingly obscure, even at the margin, and almost totally effaced near the beak;
assuming much of the character of the true Martinia. The mesial elevation and corresponding hollow are, in
general, free from sulci; the cardinal area is very short; the beaks tumid, much ineurved, but not close. Length

one inch four lines, width one inch three lines.

BRACHYTHYRIS OVALIS. Phil. sp.
Spirifera ovalis. Phil. Geol. York.

Sp. Ch.—Longitudinally oval, beaks approximate; cardinal area narrow, triangular; seven or eight ob-
tusely rounded ribs on each side the mesial fold, which is prominent, rounded, smooth, and without plaits.

This is one of the very few Spirifers in which the length exceeds the breadth; in the present species the
length exceeds the width by only one-twelfth, yet it nevertheless gives a remarkable outline to the shell,
which is commemorated in Professor Phillips’ specific name; it is, in fact, almost perfectly oval, the long axis
being in the direction of the length of the shell; the mesial fold is broad, rounded, and perfectly smooth.

Length one inch, width eleven lines, depth seven lines.

BRACHYTHYRIS PINGUIS. Sow. sp.
Spirifer pinguis. Sow. Min. Con.
Sp. Ch.—Globose, beaks very approximate; mesial fold round, prominent, distinctly defined, and without

plaits; length and width equal, depth exceeding the length of the ventral valve.
20

146 SYNOPSIS OF THE CHARACTERS OF THE

This is the only common species of the genus Brachythyris. It is, perhaps, sufficiently described in the
above character: I may add, however, that Sowerby considered a sulcus down the middle of the mesial eleva-
tion, and the absence of sulci in the mesial hollow, to be important characters; the mesial ridge is, however,
perhaps oftener found without a mesial sulcus than with, and the mesial hollow frequently exhibits obscure
sulci, or traces of ribs. Bronn has confounded the present shell with the Spirifera ostiolata of the Hifel; it
is, however, distinguished at a glance by its short hinge-line and approximate beaks. I have not quoted Pro-
fessor Phillips’ figure for this species, as that appears to me to be the young of Spirifera rotundata, as is indeed
suggested by himself in the text. Many authors have considered this shell to be the young of Spirifera rotun-
data, but it may be distinguished from all ages of that species by its width never exceeding its length, its greater
depth, and its consequently obtuse edge. From Brachythyris integricosta itis known by its want of plaits on
the mesial fold. Length one inch.

BRACHYTHYRIS PLANATA. Phil. sp.
Anomites rotundata. Martin, Pet. Derb.—Spirifera planata. Phil. Geol. York.

Sp. Ch.—Orbicular ; ventral valve plane ; radiations numerous, obtuse.

The almost perfect flatness of the lesser valve of this species forms one of its most remarkable peculiarities.
The longitudinal ribs are flattened; there are three on the mesial fold, and eleven or twelve on each side. It
appears to me that this is the shell intended by Martin as his Anomites rotundatus, and not the Spirifer rotun-
datus of Sowerby; the small size, circular outline, flatness of the smaller valve, and want ofthe mesial elevation,
agreeing much better with the present fossil, than with Mr. Sowerby’s species. Professor Phillips’ name is,
however, so well established for this species, and the shell described in the Mineral Conchology, from being one
of the most abundant mountain limestone fossils, is so well known by Mr. Sowerby’s name, that to transpose
their specific appellations would be productive of more inconvenience than the mere establishing the priority of
Martin’s name for the present species would perhaps warrant. Length one inch, width the same.

BRACHYTHYRIS PLANICosTATA. M‘Coy. (Pl. X-XI. fig. 5)

Sp. Ch.—Shell transversely oval, gibbous, rounded; mesial elevation large, square, defined ; entire surface
radiated with numerous, narrow, smooth, flat ribs.

This species resembles the Spirifer exaratus of Fleming, in the singular character of the two valves being
almost invariably found apart, and, I might add, in the great rarity of the smaller valve in most localities. From
the dark limestone at Killymeal, Dungannon, I have seen many specimens of the large valve, which is very com-
mon there, while I have seen but one or two examples of the small valve; while, on the other hand, in the
limestone of Mullaghfin, Duleek, the two valves are equally common, and almost always found in contact. The
specimen figured is from this latter locality. Length two inches, width three inches.

Atuyris. M‘Coy.

Gen. Ch.—Nearly orbicular, small; no cardinal area or hinge-line; spiral appendages very large, filling
the greater part of the shell.

This very interesting group possesses all the external characters of the T'erebratulide, united to the inter-
nal structure of the Spirifers, to which latter family it truly belongs. Professor Phillips is the only author
who has recognized the group; he forms of it his last division of the genus Spirifera, but gives no characters
to distinguish it from Terebratula; the internal structure is, however, a sure guide.

CARBONIFEROUS FOSSILS OF IRELAND. 147

ATHYRIS CONCENTRICA. Von Buch. sp.
Terebratula concentrica. Von Buch.

Sp. Ch.—Orbicular, convex, an obtusely rounded, mesial fold; surface concentrically striated.

This species is not uncommon; it is figured in the Bul. de la Soc. Geol. de France, with a perforated
beak, as in Terebratula. I have, however, seen numerous specimens with the beak entire and imperforate,
as in the other Palwozoic species.

ATHYRIS DECUSSATA. Sow. SP.
Atrypa decussata. Sow. Geol. Trans.—Spirifera decussata. Phil. Pal. Fos.

Sp. Ch.—Orbicular, length and width nearly equal, convex; surface marked with sharp, concentric, im-
bricating striz, crenulated by very fine, radiating lines.

This pretty species is very abundant; it differs from the §. concentrica, Von Buch, in the absence of a
mesial fold, and in the distinct, radiating strie. Length eight lines, width nine lines.

Atuyris pepressA. MM‘Coy. (Pl. XVIIL fig. 7).

Sp. Ch.—Transversely oval, depressed; width exceeding the length by one-fifth; surface with equal,
transverse, imbricated laminz, having their margins minutely dentato-tubercular; mesial fold large, undefined,
rounded, prominent.

This fossil occurs in abundance in certain localities; the specimens are generally more or less crushed, so
as In some measure to conceal the characters of the species. The curious, tubercular, tooth-like fringe to the
transverse laminz will, however, serve to distinguish even fragments of the shell. Length one inch and a half,
width one inch ten lines.

ATHYRIS EXPANSA. Phil. sp.
Spirifera expansa. Phil. Geol. York.

Sp. Ch.—Transversely elliptical; width very little exceeding the length; very depressed; edge obtuse ;
no mesial fold; obtuse, imbricating, concentric stri, and very faint, radiating lines.

This species is very nearly allied to the 4. glabristria, but wants the mesial fold, which in that species is
very prominent; itis greatly more depressed, the depth being less than one-third ofthe width; the edge is obtuse
in this, but sharp in the former species; the concentric striz are always present, but never very prominent,
as in the Athyris squamosa, they are obtusely rounded, not assuming the form of erect scale-like lamine as in
that species. The usual length is about one inch three lines; the width one inch and a half.

Arnyris FIMBRiATA. Phil. sp.
Spirifera fimbriata. Phil. (Not figured).

Sp. Ch.—Nearly orbicular; depth half the width; coarse, rounded, radiating strix, decussated irrecularly
by thick, prominent, lines of growth; edge of the valves rounded, obtuse; no mesial fold.

Iam not aware of any published figure of this species, which is very rare. The radiating strie are
uncommonly thick, smooth, rounded, but not very prominent; the concentric ridges are rather irregular in
their distance one from the other; these, together with the blunt edge, give an unshapely appearance to the
shell; it is a small species, rarely exceeding half an inch in length; the width is very little greater than
the length.

148 SYNOPSIS OF THE CHARACTERS OF THE

Avuyris GLABRISTRIA. Phil. sp.
Spirifera glabristria. Phil. Geol. York.

Sp. Ch.—Transversely elliptical, depressed; mesial fold large, prominent, undefined, obtusely rounded ;
surface smooth or with faint radiating striz.

This is one of the many smooth Spirifers which runs a risk of beg confounded with the Spirifera
(Martinia) glabra. Thatshell has, however, a large cardinal area, while this has no trace of one. The present
shell is very constant in general outline, but varies in depth from one-half to one-third of its width; the beaks
are very small; the surface is usually smooth, but, if finely preserved, shows delicate, radiating striz. The lines
of growth are only conspicuous near the margin, but do not affect the general smoothness of the surface.
Length one inch three lines, breadth one inch ten lines.

ATHYRIS GLOBULARIS. Phil. sp.
Spirifera globularis. Phil. Geol. York.

Sp. Ch.—Orbicular, ovate, subglobose ; mesial fold wide, obtuse; surface smooth, with fine lines of growth.

This species is rather longer than wide, very gibbous, the depth being equal to about two-thirds the width ;
the surface is smooth, with the exception of a few lines of growth ; the mesial fold is wide, but not very promi-
nent; both mesial ridge and furrow are frequently divided by a fine, impressed line.

The spiral appendages in this species are of great size, filling almost the entire shell; the apices of the
cone, instead of being directed upwards towards the beak, as in the true Spirifers, are directed downwards
towards the front margin. This fossil is of very local occurrence in Ireland; it rarely exceeds three-quarters
of an inch in length.

ATHYRIS HISPIDA. Sow. SP.
Atrypa hispida. Sov. Geol. Trans.

Sp. Ch.—Transversely oval, convex; beaks small; surface concentrically imbricated by broad lamelle ;
concentrically fringed, with strong, spine-like striz.

When well preserved the Athyris decussata puts on precisely the surface of this species, the concentric
strie of that shell being the basis, or remains of concentric, broad lamellae, such as we see in the Actinoconchus
paradoxus and Athyris sqguamosus, and being, in both shells, decussated by similar strong strie, which give a
fringed appearance to the surface when irregularly worn. Length six lines, width seven lines.

ATHYRIS PLANOSULCATA. Phil. sv.
Spirifera planosulcata. Phil. Geol. York.

Sp. Ch.—Pentahedral, depressed at the sides, tumid in the middle; centre of each valve with a broad, well-
defined mesial sulcus.

The surface of this curious species is perfectly smooth, it is very much depressed at the sides, but some-
what tumid in the middle, the ventral valve having a mesial hollow, as well as the dorsal, forms a very peculiar
character. About an inch im length, width very little greater than the length.

Aruyris squamosa. Phil. sp.
Spirifera squamosa. Phil. Geol. York.—Spirifer lamellosus. Lévézllé, Mém. Geol. Soc. de France.—Spirifer De Roissyi.
Lév. Mém. Geol. Soc. de France.
Sp. Ch.—Transversely elliptical, or subrhomboidal ; depth half the width; mesial fold narrow, prominent ;
frequently divided by a mesial sulcus; surface with distant, erect, concentric lamin of growth.

CARBONIFEROUS FOSSILS OF IRELAND. 149

This is one of the most elegant shells of its genus, and is rendered particularly striking by its erect lamine
of growth; these are usually about nine in number, perfectly continuous across the shell, and, when well pre-
served, stand a line or more in height*, perpendicular to the surface of the valve, they are about a line and a
half distant from each other, the spaces between them being perfectly flat and smooth. The mesial ridge,
though narrow, is rounded and very prominent at the margin, but becomes obscure towards the beak of the ven-
tral or smaller valve; the mesial sulcus on the dorsal or larger valve is, however, sharply defined, and continues
distinct up to the beak. Length usually one inch, width about one-fourth greater than the length, depth one-

half the width.

Aruyris (?) TRILOBA. M‘Coy. (Pl. XX. fig. 21).

Sp. Ch.—Longitudinally ovate, subtrigonal; mesial fold very broad, prominent, shehtly convex, divided
by a faint mesial suleus; sides rounded, narrower than the mesial fold; surface regularly marked by strong,
transverse, imbricating lamin of growth.

This shell is so distinct from the other Brachiopoda of the formation, that it is not likely to be confounded
with any other species; the great width of the mesial fold is very remarkable; the surface is smooth, with the
exception of the regular, thick laminz of growth. Length five lines, width six lines.

Actinoconcnus. MM Coy.

Gen. Ch.—Shell globose; the margin of both valves greatly extended, forming a flat, circular, stri-
ated disc ; spiral appendages as in Athyris.

I founded this genus several years ago, in a paper read to the Geological Society of Dublin, for the recep-
tion of a very singular fossil, occasionally found in the lower members of the carboniferous series. Specimens
such as are usually found, present the appearance of some globular, smooth species of Atrypa which had by ac-
cident fallen on a portion of an Orthis Pecten, or some such fossil; the discrepancy between the smooth,
globose shell, and its flat, striated margin, being so great, that few would imagine they were parts of the same
species. The discovery of the specimen figured, Pl. X XI. fig. 6, a, first led me to consider them as parts of the
one shell, by exposing the upper valve perfect, the beak of the lower valve, and the flat, striated lamine ap-
pearing from between them ; but it was not until I received the specimens, fig. 6, 6, that the structure of the shell
was at all clear.

The central globular portion resembles a smooth Terebratula, or Atrypa, with a few concentric lines of
growth, but the dorsal valve, as far as I can judge from the specimens I have examined, is quite imperforate ;
the few concentric lines of growth I imagine to be the remains of disciform margins to the valves of the young
shell, such as are now seen in the old; and as the shell advances in growth, the two flat margins, instead of
being in contact, and affording each other mutual support, become erect, insulated, scale-like lamin, liable to
be broken off by the slightest accident; so that each line of growth, or former margin of the shell, might have
been dilated, as in the example figured, as long as it was the margin; but when a new edge was formed be-
tween the two old discs, they fell off as superfluous, like the tip of Bulimus decollatus, merely leaving a concen-
tric line of growth to mark their places. The same thing can be seen in such shells as the T'ridacna squamosa,
where those scales near the beak are always effaced, and thus it is that we only find the two last formed dises
on the present shell; occasionally, however, we find portions of the old margins, which, having been supplanted,
are in a state of decay; a specimen of this kind is figured, Pl. X XI. fig. 6, a, in which two discs are visible on
each valve, the one broken and in a state of decay, the other projecting far beyond it.

* Since writing the above I have seen a specimen from the Cork limestone, in which the lamine nearest the edge
were prolonged nearly an inch from the surface of the shell, and radiatingly furrowed, as in the Actinoconchus paradoxus,

M‘Coy; this latter may therefore be an Athyris.
Pe

150 SYNOPSIS OF THE CHARACTERS OF THE

Acrrivoconcuus pArRADoxus. M‘Coy. (Pl. XXI. fig. 6).
Terebratula Roissyi. Vernewil. Bul. Soc. Geol. Fran.

The depth of the smooth, central portion is equal to two-thirds its length, measured from the beak to the
commencement of the striated portion. The disc has, at its origin, a narrow space, quite smooth, and free from
strie; the disc itself has numerous fine, radiating sulci, at equal distances, the spaces between them flat. In
general, the central portion is dull, while the dise possesses a slightly lustrous, or shining appearance ; length of
central portion eight lines, breadth seven lines; dise projects about three-fourths of an inch beyond the shell
on every side, excepting a space at the beak. Since I read the paper above referred to, M. de Verneuil pub-
lished a description of this fossil in the Bul. Geol. Soc. de France, under the name of T'erebratula Roissyi,
stating the beak to be perforated, as in the recent Terebratule, and referring it to the Spirifer Roissyi of
L’Eveille; as I have taken different views on both those points, and had described it so long before, I have re-
tained my old name.

Famity TEREBRATULID.

The Tvrebratulide may be divided into the following genera: 1. Delthyridea, M‘Coy (Fig. 27), or those
species which have a long hinge-line, and a distinct, cardinal area (as in the Delthyride or Spirifers), the
deltidium fissured in the middle; all the species of this genus are largely plaited; 2. Terebratula (Fig. 28)
(as here restricted), composed of those species which have the beak truncated so as to form a large circular per-
foration; the deltidium only reaches to the anterior margin of the foramen, not extending round it; all the
smooth, perforated species belong to this genus; 3. Cyelothyris, M‘Coy (Fig. 29), formed of those curious

Fig. 27.

/
Fig. 29. Fig. 30. Fig. 31.
iw
Uf Ss

species in which the deltidium completely encircles the foramen; 4. Atrypa, Dal. (Fig. 30) (as here re-
stricted), composed of those species which are destitute of a foramen and deltidium at all periods of their hfe;
and, 5. Seminula, M‘Coy (Fig. 31), a genus formed for the reception of those little species which have a
minute perforation, but want the deltidium. The two last genera are the only ones found in the Palozoic
rocks, and include all the so-called Terebratule of these formations.

Gi

ci

Vata y

Atrypa. Dal. (Restricted).

Gen. Ch.—Fquilateral, inequivalve; dorsal valve imperforate, and without deltidium; no hinge-line,
brachial supports simple, flat, triangular.

The term Atrypa has, of late, been used in so wide a sense, that its restriction, as in the present instance,
to the imperforate Terebratule of the older rocks may be convenient*, The species of this genus, as now

* Mr. Sowerby makes it include some of the present shells, and also the smooth Spirifers, with a short hinge-line and
wide cardinal area (Martinia, M‘Coy); the imperforate Spirifers, without hinge-line, cardinal area or foramen, but pos-
sessing the spiral appendages (Athyris, M‘Coy); and some others.

CARBONIFEROUS FOSSILS OF IRELAND. 151

restricted, are very numerous and extremely various in their form, some being transverse, others elongate ; some
having a smooth surface, and a still greater number plaited longitudinally.

The genus Aérypa, according to our view, includes all those species of Terebratuliform shells which are
without a distinct perforation in the dorsal valve; and of course as wanting the perforation, they also want the
deltidium ; they were, therefore, probably, free shells, another very interesting peculiarity, in which they differ
from the Terebratule.

I have been enabled to discover the internal structure in many of the species, and find it to be much more
simple than that of the more typical groups; the supports of the arms assume the form of two broad, flat, trian-
gular processes, narrow at their origin near the beak of the ventral valve, and increasing in breadth towards
their free extremities, where they are obliquely truncated; they are not recurved in any of the species, nor is
there any connecting process between them. The arms were probably free, and capable of being protruded for
the greater part of their length. This group is generally confounded with the imperforate Spirifers, formimg the
genus Athyris, M‘Coy, but is at once distinguished by the simplicity of its internal supports, these parts being
very long, and spirally coiled in the latter genus. Professor Phillips’ genus Cleiothyris appears to include
them both.

The genus Atrypa is exclusively confined te the Paleozoic rocks.

ATRYPA ACUMINATA. Mart. sp.

Anomites acuminatus. Martin, Pet. Derb.—Terebratula acuminata. Sow. Min. Con.—Terebratula acuminata.
Phil. Geol. York.

Sp. Ch.—Tetrahedral, ventral valve very much elevated, obtusely keeled in the middle; dorsal valve
small, concave; margin sharp, forming a very acute sinus in the front.

This species is subject to an extraordinary degree of variation in its form. The most usual and typical

Fig 32. form is that described in the above specific character, but others occur in which the sinus in
the front is obtuse and plaited, and others with lateral plaits are not uncommon. Some spe-
cimens are depressed, as the 7’. platyloba, Sow.; all the varieties have the surface smooth to
the naked eye, but minutely striated under the lens. The internal structure is similar to
/ that of the 4. hastata, but the supports are smaller in proportion to the size of the shell (see
fig. 32). This is a local species in Ireland, but where it does occur it is usually very abundant.
Length one inch three lines, width one inch five lines.

ATRYPA ANGULARIS. Phil. sp.
Atrypa primipilaris. Sow. Geol. Trans. (not of Von Buch).—Terebratula angularis. Phil. Pal. Fos.

Sp. Ch.—Pentagonal, wider than long; mesial fold large, prominent, sharply defined, flattened; surface
radiated with numerous, irregular, branching striz. Length three and a half lines, width four lines.

ATRYPA ANISODONTA. Phil. sp.
Terebratula anisodonta. Phil. Pal. Fos.

I have considered as this species, those specimens agreeing with 7’. pleurodon in general form, but having
the plaits rounded, and becoming obsolete towards the beak.

ATRYPA ASPERA. Dal.
Terebratula aspera. Schlot.—Atrypa squamosa. Sow. Geol. Trans.

Sp. Ch.— Outline from transversely oval to longitudinally obovate, dorsal valve very convex; ventral
valve less so, beaks prominent; surface radiated with from fourteen to eighteen strong, rounded ribs, with rather
distant, concentric rows of large, scale-like lamine of growth.

152 SYNOPSIS OF THE CHARACTERS OF THE

This handsome species is very rare; the Irish specimens are identical with those of the Eifel and Devon-
shire, but not with the Silurian ones.

ATRYPA BIFERA. Phil. sp.
Terebratula bifera. Phil. Pal. Fos.

Sp. Ch.—Subrhomboidal, very much depressed; mesial fold very wide, shallow; beaks small, pointed;
surface radiated with very numerous, rounded, much branched striz.

This species is rather rare. I described it several years ago in a paper to the Geological Society of
Dublin (previous to the publication of the Paleozoic fossils), under the name of dtrypa dichotoma, and subse-
quently published a short description of it in a catalogue which I wrote, of my friend the late Major Sirr’s
fossils. Length seven lines, width nine lines.

ATRYPA CANALIS. (?) Sow. sp.
Terebratula canalis. Sow. Sil. Syst. (?)

A few obscure specimens, from the very bottom of the carboniferous series, have, with great doubt, been
referred to this species; they resemble the Atrypa sacculus, but are rather narrower, and with a deep sulcus
from the beak to the front margin.

AtTRyYPA compTA. Phil. sp.
Terebratula compta. Phil. Pal. Fos.
Sp. Ch.—Obscurely pentagonal, valves nearly equally convex, front truncated; surface with numerous
equal, radiating ridges. Length five lines, width four and a half lines.
A few obscure and imperfect specimens only have been observed.

ATRYPA CORDIFORMIS. Sow. SP.
Terebratula cordiformis. Sow. Min. Con.
Sp. Ch.—Cordiform, acuminated; front very much elevated, with about five acute plaits extending half
way to the beak; sides tumid.

This species is chiefly distinguished from one of the varieties of the A. aewminata, by being more convex
or tumid at the sides, and in the length and distinctness of the mesial plaits.

ATRYPA DESQUAMATA. Sow.
Atrypa desquamata. Sow. Geol. Trans.—Terebratula (Atrypa) desquamata. Phil. Pal. Fos.
Sp. Ch.—Longitudinally obovate, convex; beak large, prominent; surface covered with deep, narrow,
smooth striz, very much branched as they approach the margin.
This species varies considerably in form, some specimens being nearly square and much flattened; they
are more commonly however as above described ; some specimens have the front slightly elevated, in others it

is plane. Length about one inch and an half, width one inch five lines. I have not seen the perforation be-
neath the beak.

ATRYPA EXCAVATA. Phil. sp.
Terebratula excavata. Phil. Geol. York.

Sp. Ch—Rhomboidal, very gibbous, beak of dorsal valve large, prominent; sides concave; three very
large, angular, mesial plaits, and two on each side.

This curious species is distinguished by the great size of its plaits, and the concave space on each
side of the beak, which is large, prominent, and not much incurved; the mesial elevation is very high, the
depth and width being about equal. Length nine lines, width eleven lines.

CARBONIFEROUS FOSSILS OF IRELAND. 153

ATRYPA FALLAX. Sow.
Terebratula pleurodon. Phil. (pars).—Atrypa fallax. Sow. Geol. Trans.

Sp. Ch.—Nearly orbicular, convex; beaks prominent, pointed; mesial elevation slight, undefined; sur-
face radiated, with about sixteen or eighteen strong, angular plaits, continuing sharp and distinct to the beak.

This is one of the forms considered by Professor Phillips to be a variety of the 4. pleurodon; it is at least
a distinet variety, and even as such it is convenient to have a name. Length six lines, width eight lines.

Atrypa FerIta. Von Buch. sp.
Terebratula ferita. Von Buch. Tereb.—Terebratula ferita. Phil. Pal. Fos.

Sp. Ch.—Longitudinally ovate, subpentagonal; beaks narrow, pointed; surface with about seven very
large, angular ridges.

This species is too distinct in its plication, to be confounded with any other. Length three lines, width
two and a half lines.

ATRYPA FLEXISTRIA. Phil. sp.
Terebratula flexistria. Phil. Geol. York.

Sp. Ch.—Transversely ovate, tumid; mesial elevation very large, rounded; about nine obtuse plaits raised
with the front margin; the lateral plaits arched; beak small.

This species differs from the A. ventilabrum in the great curvature of the lateral plaits; also in the size of
its rounded mesial lobe: all the plaits are obtusely rounded. Length eight lines, width ten lines.

ATRYPA GREGARIA. M‘Coy. (Pl. XXII. fig. 18).

Sp. Ch.—Trigonal; beak of the dorsal valve very large, produced, incurved; dorsal valve flattened; sides
abruptly rounded; a very wide, but shallow, mesial depression, slightly produced infront; ventral valve an equi-
lateral triangle; all the angles rounded, very convex; front margin raised to a broad sinus; surface smooth.

This curious species is very remarkable in form, wholly unlike any of the other Palaeozoic species, ap-
proaching nearly in size and shape to the Terebratula lineolata, Phil., of the Speeton clay; it is the only true
Atrypa 1 know of, resembling in this respect several of the attached Terebratule of the more recent forma-
tions. Length seven lines, width six lines, depth three lines and a half.

ATRYPA HASTATA. Sow. SP.
Terebratula hastata. Sow. Min. Con.—Terebratula hastata. Phil. Geol. York.

Sp. Ch.—Ovato-pentagonal, depressed; front truncate, slightly emarginate, depressed; sides of the beak
angulated; surface smooth; breadth two-thirds the length, which is usually one inch.

This fossil is very abundant. The valves are more nearly equal than is usual im species of this genus;

the outline of the young shell is regularly ovate, but becomes pentagonal as it increases in size; the

Fig. 33. front, in young individuals, is rounded, but in old shells truncate, and somewhat wedge-

aN shaped, from the depression of the middle of the valves; there is an obtuse keel on each side of

the beak of the dorsal valve. The internal supports or cardinal teeth of the ventral valve, I

Mi have found to be composed of two flat, triangular laminz, having the ventral edge convex, and

the dorsal edge concave; they increase in breadth towards the anterior end, where they are

/ obliquely truncated. They arise in the usual manner, one on each side of the beak of the ventral

—_ valve, diverging as they approach the front margin. They reach, in the present species, some-

what less than half the length of the shell (see fig. 33). Length one and three quarter inches, width one

inch.

2Q

154 SYNOPSIS OF THE CHARACTERS OF THE

ATRYPA INDENTATA. Sov.
Atrypa indentata. Sow. Geol. Trans.
Sp. Ch.—Transversely oval, convex ; front indented, beaks very small, prominent; abdominal edge of the
lower valve elevated, surface smooth.
The surface of the upper valve is evenly convex, no mesial ridge being formed by the elevation of the
front margin; the form is nearly orbicular, slightly wider than long. Length three lines, width three and a

half lines.

ATRYPA INSPERATA. Phil.
Terebratula (Atrypa) insperata. Phil. Pal. Fos.
Sp. Ch.—Longitudinally oval, depressed; surface radiated with large, rounded, dichotomous ribs, about

six of them in the middle of the dorsal valve slightly elevated.
A single very imperfect specimen of this species has occurred.

Atrypa isornyncHa. M‘Coy. (Pl. XVIL fig. 8).

Sp. Ch.—Shell subglobose, depth exceeding the width, rather square, strongly plaited; mesial elevation
square, of four plaits; beaks obtuse, nearly equal, with a triangular flattened space on each side; plaits twenty,
obtusely angular.

The flattened or very slightly concave spaces on each side of the beak closely ally this remarkable fossil
with such species as the 7’. plicatilis and T. serrata of the Oolite, and the few other fossils which possess this

curious character.
It may be known from the 7’. excavata of Phillips by the greater number of its plaits, which in that species
rarely exceed seven. Length ten lines, width one inch, depth one ch one line.

ATRYPA JUVENIS. Sov.
Atrypa juvenis. Sow. Geol. Trans.—Terebratula juvenis. Phil. Pal. Fos.

Sp. Ch.—Longitudinally ovate, narrow towards the front, depressed, smooth; beak of dorsal valve very
small, much incurved, strongly angulated at the sides.
The outline of this species is very remarkable, from the greatest transverse diameter being near the beak.

Very rare.

ATRYPA LACHRYMA. Sow.
Atrypa lachryma. Sow. Geol. Trans.

Sp. Ch.—Longitudinally ovate, valves nearly equal, very convex; beaks very small; front margin with a
small, deep sinus; mesial sulcus of the dorsal valve broad, flat; surface smooth.

This little shell closely resembles the young of TJ. sacculus, but is obviously distinct, by its raised margin
and small beaks. Length five lines, width four lines, depth three and a half lines.

Atrypa LaTicitiva. M‘Coy. (Pl. XXII. fig. 16).

Sp. Ch.—Transversely rhomboidal, length two-thirds the width, gibbous; middle of the shell elevated in
front, with three obtuse ribs, reaching nearly to the beak; between the mesial elevation and the sides is a smooth
space, equal in breadth to the mesial elevation; sides small, compressed, with three obtuse ridges, reaching half
way to the beak.

This species is remarkable for the small number of its ribs, and the broad space between those of the me-
sial elevation and the sides. Length six lines, width nine lines.

Or

CARBONIFEROUS FOSSILS OF IRELAND. 15

Atrypa LaTicosTa. Phil. sp.
Terebratula laticosta. Phil. Pal. Fos.

A few fragments of a large Atrypa, with broad, rounded, transversely striated ribs, have been referred to

this species with doubt.

AtrypaA NANA. M‘Coy. (Pl. XXII. fig. 19).

Sp. Ch.—Orbicular, or slightly ovate, compressed, beak pointed; surface radiated with about ten, straight,
equal, obtusely angular ridges, none of which reach the beak.

This little species resembles the 7’. radialis in form, but is much flatter, and has considerably fewer, larger,
and more angular ribs, all of which disappear before reaching the beak, as in the A. subdentata and rotunda,
Sow., from both of which it is distinct, by its greater flatness, and more numerous radiating ridges; it is also
much smaller than any of those shells. Length two lines, width two lines.

ATRYPA ? OBLONGA. Sow.
Atrypa oblonga. Sow. Geol. Trans.

A few very obscure casts, resembling Mr. Sowerby’s figure of this rather doubtful species, have occurred.

Atrypa? optusa. M'Coy. (PI. XXII. fig. 20).

Sp. Ch.—Orbicular, convex; length and width equal, depth two-thirds the width, margin very obtusely
rounded; surface marked with rather distant, smooth, concentric striz.

The margin of this species is broadly rounded, and the edges being thickened, give, particularly to old
individuals, a peculiarly rugged character to this portion of the shell, very unusual in the genus Atrypa; the
concentric lines are very delicate and more distant than those of the A. concentrica, scarcely interrupting the
smoothness of the surface; the thickened edges and obtusely rounded margin distinguish it from the A. con-
centrica and other allied species. It probably should be referred to Athyris. Length one inch two lines, width

the same, depth ten lines.

ATRYPA PLATYLOBA. Sow. SP.
Terebratula platyloba. Sow. Min. Con.

This very depressed variety of the 4. acuminata is not uncommon in several localities.

ATRYPA PLEURODON. Phil. sp.
Terebratula pleurodon. Phil. Geol. York.

Sp. Ch.—Transversely oval; mesial elevation large, square, with several large, acutely angular plaits,
which reach to the beak, forming deep notches or teeth in the margin.

This species is exceedingly variable in the number of the mesial and lateral plaits, but in all instances they
are acute, and extend perfectly distinct to the beak, which characters serve to distinguish all the varieties; the
lateral plaits are of unusually large size, and form deep notches in the side margin. The form also varies con-
siderably, but the character of the ribs seems to distinguish the species under all its modifications. Length nine
lines, width one inch.

Arrypa prisca. Schlottheim. sp.
Terebratulites priscus. Schlottheim. Petref—Terebratula affinis. ‘Sow. Min. Con.
Sp. Ch.—Longitudinally ovate or subtrigonal; front very narrow, rounded; sides nearly straight; beaks

small; ventral valve most convex ; surface covered with very numerous, rounded stria, which frequently
branch as they approach the margin, and are crossed by close, imbricating lamine of growth.

156 SYNOPSIS OF THE CHARACTERS OF THE

This species in general form and striation is analogous to the 4. desquamata, but that species is dis-
tinguished, as its name implies, by the absence of the concentric, scale-like striation of the present shell.
Length one inch two lines, width one inch.

ATRYPA PROAVA. Phil. sp.
Terebratula proava. Phil. Geol. York.

Sp. Ch.—Longitudinally obovate; beak of the dorsal valve large, produced; front broad, rounded; mesial
fold square ; surface radiated with numerous, obtusely rounded ridges, which reach little more than half way to
the beak, leaving the rostral portions smooth.

A few small, obscure specimens only have occurred of this curious species. Length six lines,

Atrypa pucnus. Mart. sp.

Anomites pugnus. Martin, Pet. Derb.—Terebratula pugnus. Sow. Min. Con.—Terebratula pugnus. Phil. Geol. York.
Fig. 34. Sp. Ch.—Ovato-deltoidal, smooth; dorsal valve evenly convex; front much elevated,

with four or five very short, obtuse plaits in the middle, and three or four on each

ZEN side.

The most remarkable character of this species is the shortness of the marginal plaits,
? which from some fancied resemblance to the knuckles of a clenched fist, have suggested the
specific name. The ventral valve is evenly convex and smooth. Length nine lines, width

one inch. Fig. 34 exhibits the brachial appendages in this species, they are remarkably
small, and similar in form to those of most of the plaited species.

ATRYPA RADIALIS. Phil. sp.
Terebratula radialis. PA. Geol. York.

Sp. Ch.—Suborbicular, beaks pointed, small; valves almost equally convex; no mesial fold; surface
radiated with fine, equal, rounded ridges.

This pretty little species is rather rare; length usually about three lines, width the same.

ATRYPA RENIFORMIS. Mart. sp.

Anomites reniformis. Mart. Pet. Derb.—Terebratula reniformis. Sow. Min. Con.—Terebratula reniformis. Phi.
Geol. York.

Sp. Ch.—Reniform; front margin raised so as to form a square sinus, from which about four obtusely
rounded plaits reach nearly to the beak; sides smooth, tumid, without plaits.

This species is remarkable for the tumid or inflated appearance of the sides, and this in both the dorsal and
ventral valves; so that at the sides, the dorsal valve presents the unusual appearance of hanging below the
margin; this character will easily distinguish the present species from those nearly allied; the mesial plaits
are obtusely rounded, but the notches they form in the margin are acute. Length one inch, width one inch
five lines, depth seven lines.

ATRYPA sAccuLUS. JVWart. sp.

Anomites sacculus. Mart. Pet. Derb.—Terebratula sacculus. Sow. Min. Con.—Terebratula sacculus. Phil. Geol. York.

Sp. Ch.—Obovate, very gibbous, edge rounded, obtuse; front indented, a deep, mesial furrow; surface
smooth.

This little shell is very gibbous; it differs from all the varieties of the A. hastata in the great convexity
of its valves, blunt, rounded edges, the form of the indentation in the front of the deep mesial hollow, and its
small size, it rarely exceeding half an inch in length; the mesial hollow in the dorsal valve is narrow, but so

CARBONIFEROUS FOSSILS OF IRELAND. 157

deep as almost to divide the shell into two lobes. Martin describes the beak of this species as perforated, but I
think it must have been from accident, or perhaps wear, as some specimens now before me seem perfectly im-
perforate. Length six lines, breadth four lines.

AtTrRYPA SEMiIsuLcATA. MM'‘Coy. (Pl. XXII. fig. 15).

Sp. Ch.—Orbicular, depressed; beak small; mesial fold broad, flat, with about five, strong, rounded,
radiating ridges, continued to the beak; sides smooth, or very finely striated longitudinally.
This species is very remarkable, from its coarsely ridged mesial fold, and nearly smooth sides.’ Length

seven lines, width eight lines.

ATRYPA STRIATULA. Sow.
Atrypa striatula. Sow. Geol. Trans.

A few nearly hemispherical casts in decomposing slate are the only data we have for the occurrence
of this species in Ireland, they shew a very fine striation on some parts of the surface; Mr. Sowerby’s original
description and figure appear to have been from equally imperfect specimens; before receiving his definition,
I considered the Irish fossils to belong to the genus Orthis, although they are too imperfect to be certain of

the fact.

ATRYPA SUBLOBATA. Porth.
Atrypa sublobata. Porth. Geol. Rep.

T feel the definition of this very remarkable species so difficult, that I must refer to Captain Portlock’s
figures and description, from which the reader will gain a much clearer idea of the species than T could convey.
I may, however, state, that in the same locality, namely, the red sandstone of Kildress, Cookstown, I have ob-
served all the forms noticed by that author.

ATRYPA suLcIrostris. Phil. sp.
Terebratula sulcirostris. Phil. Geol. York.

Sp. Ch.—Transversely oval, tumid; front much elevated, with about five large, rounded, distinct plaits,
which are continued to the beak; there are usually four broad, flattened plaits on each side, which do not reach
the beak, but form large, acute notches in the margin.

This species receives its specific name from the prolongation of the mesial plaits to the beaks, giving them
asuleated appearance. The lateral plaits are broader than the mesial ones, greatly flattened, and disappear
when they reach about half way to the beak. Length seven lines, width six lines.

ATRYPA TRIANGULARIS. Sow.
Atrypa triangularis. Sow. Geol. Trans.

A few very obscure specimens have occurred, resembling some of the smaller varieties of the 4. acumi-
nata, but I have referred them provisionally to Mr. Sowerby’s species.

ATRYPA TRIPLEX. M‘Coy. (Pl. XXII fig. 17).

Sp. Ch.—Transversely oval, gibbous; beaks very small, pointed; surface with nine short, angular ribs,
which reach but half way to the beak; front elevated with three of the ridges; the three ridges on each side
slightly larger than the mesial ones.

This pretty little shell is remarkable for its three equal lobes, of three ridges each, it is distinguished from

2R

158 SYNOPSIS OF THE CHARACTERS OF THE

the A. raricosta, Phil., by the ridges extending only half way to the beaks on the ventral valve, and its very
small size. Length two and a half lines, width three lines.

ATRYPA VENTILABRUM. Phil. sp.
Terebratula ventilabrum. Phil. Geol. York.

Sp. Ch.—Deltoidal, gibbous; about five distinct, rounded plaits abruptly raised with the margin in front,
about ten distinct, rounded, lateral plaits.

The great number and distinctness of the lateral plaits distinguishes this from A. sulcirostris, to which it
is otherwise similar. The margin of the present shell is usually sharper, and the valves more depressed than in
that species; the frontis frequently much produced; the lateral plaits are smaller than the mesial ones, but are
perfectly distinct, and continued nearly to the beak. Length nine lines, width one inch.

Arrypa vircowes. M‘Coy. (Pl. XXII. fig. 21).

Sp. Ch.—Longitudinally oval; width two-thirds the length; evenly convex; front narrowed, straight;
beak of the dorsal valve small, rounded, very slightly incurved; surface concentrically imbricated.

This is distinguished from the A. virgo, Phil., which it most nearly resembles by its imbricated surface, it
is also considerably larger than the South Devon shell; it differs from the A. hastata in the rounded sides of
the beak of the dorsal valve and its being very slightly incurved, as well as in its narrow front, and imbricated
surface. Like many others of the smooth, or nearly smooth Brachiopoda, it appears strongly costated longitu-
dinally when the external shell is removed. Length one inch four lines, width eleven lines.

Seminuta. M‘Coy.

Gen. Ch.—Shell small, subpentagonal; smooth, or slightly plaited at the margin; beak of the dorsal valve
small, with a minute perforation; no deltidium.

The species of this genus are all small; nearly smooth shells; the margin frequently indented, but no dis-
tinct plaits on the surface; the outline is usually more or less pentagonal; the beak has a very minute foramen
for the passage of the muscle of attachment, but there is no deltidium separating the foramen from the hinge.
The genus is peculiar to the Paleozoic rocks.

SEMINULA PENTAHEDRA. Phil. sp.
Terebratula pentahedra. Phil. Geol. York.

Sp. Ch.—Pentagonal, depressed; front and sides indented, the angles forming broad undulations on the
surface; length and breadth nearly equal, depth half the length.

This shell appears to have been gregarious, but was, at the same time, very local in its distribution, rarely
occurring, but when it does occur it is usually found in great abundance; it is of a very regular, pentahedral
figure, the spaces between the angles concave, with an indented margin. Length six lines, breadth six lines.

Semmnuba Pisum. JZ‘Coy.
Terebratula seminula. Phil. Geol. York.

Sp. Ch.—Globular; front margin elevated in the middle, with an indentation on each side. Length,
depth, and breadth nearly equal.

This little species is almost spherical; the elevation of the front margin does not affect the surface of
either valve; the two valves being evenly and nearly equally convex; the teeth or indentations in the front
margin do not produce plaits on the surface. This species appears to have been gregarious, but very local in
its distribution. Length one line and a half.

CARBONIFEROUS FOSSILS OF IRELAND. 159

SEMINULA RHOMBOIDEA. Phil. sp.
Terebratula rhomboidea. Phil. Geol. York.—Terebratula rhomboidea. Phil. Pal. Fos.

Sp. Ch.—Shell small, globose, rhomboidal; marginal elevation very high, indented in the middle; length
and breadth equal.

This small, well-marked species is extremely constant in its characters; the valves are perfectly smooth,
with the exception of the lines of increase; the two valves are equally deep; the depth of the two valves equals
half the breadth; the broad elevation of the front is not perceptible on the smaller valve, which is convex, but
forms a very wide depression in the dorsal valve; the elevation of the margin has a notch or indentation in
the middle, from which a small ridge runs through the centre of the mesial depression in the dorsal valve,
and a small groove through the centre of the ventral valve towards the beak. Length six lines, width six lines.

CRUSTACEA.

Astacus ? Paiturrsu. M‘Coy. (Pl. XXIII. fig. 1).

The very interesting fossil to which I have given the above name is, I believe, the first instance in which
any remains of the Macrourous Decapods have been found in the Irish Paleozoic strata; the specimen is from
the thin beds of limestone, intercalated with the slate of Hook Head, Waterford, where it was collected by
Mr. C. W. Hamilton, Secretary of the Geological Society, Dublin, in whose collection it is preserved. The
specimen consists of a short portion of the leg, the carpus, and the penultimate, or immoveable joint of the di-
dactyle hand or pincers, apparently of the right side; the existence of a thumb or mobile finger, and a powerful
one, is proved by the marks of muscular attachment at the base of the penultimate joint, in the situation re-
quisite for moving it; so far as preserved, the length of the penultimate joint is one inch seven lines. The car-
pus is quadrangular, wider than long, width five lines; length on the outside four lines, on the inside two lines.
The structure of the laminated shell, and of the ginglymoid joints, is still preserved.

CALYMENE (?) GRANULATA. Muiinst.
Calymene granulata. Miinst. Beitrage—Calymene granulata. Phil. Pal. Fos.

Sp. Ch.—Cephalothorax, semicircular; surface minutely tuberculated; glabella pear-shaped, very tumid ;
cheeks small, triangular, convex; eyes large, strongly reticulated; pygidium obtusely rounded, lobes tumid,
nearly equal, each segment with a transverse row of granules.

The specimens which have occurred of this species are all imperfect, but seem identical with the Devo-
nian ones. This is obviously not a true Calymene.

CALYMENE L&vIS. Muinst.
Calymene levis. Miinst. Beitrage—Calymene levis. Phil. Pal. Fos.

The specimens referred to this species are very imperfectly preserved, they present, however, the same
remarkable parallelism of the sides of the body and subtruncate tail. Ihave not seen the head.

160 SYNOPSIS OF THE CHARACTERS OF THE

CaLyMENE LATREILLU. Stein.
Calymene Latreillii. Stein. Mem. Geol. Soc. Fran.—Calymene Latreillii. Pil. Pal. Fos.
One or two fragments of the post-abdomen of a species resembling that figured by Professor Phillips, have
occurred, but too imperfect for correct identification or description.

Grirrituipes. Portk.

The genera Phillipsia and Griffithides, so common in the carb. limestone, are very distinct in their charac-
ters. In Phillipsia the glabella is as wide at the base as in front, and marked on each side with three cephalo-
thoracic furrows, which in Griffithides is gibbous in front, but contracted to a very narrow neck at the base, and
there are no lateral furrows; the eyes in the former are usually larger and reticulated, while in the latter they
seem smooth.

GRIFFITHIDES caALCARATUS. M‘Coy. (PI. IV. fig. 3).

Sp. Ch.—Cephalo-thorax, semioval; glabella smooth, ovate, most convex in the middle of its length ;
cheeks small, triangular, flat, smooth; wings strongly striated, broad, prominent, rounded, terminating poste-
riorly in long, flattened spines; eyes moderate, lunate (smooth ?), connected with the glabella by a nucleus on
each side; pygidium with a smooth margin, each segment with a row of very minute granules.

This beautiful species is most nearly allied to the G. longispinus, Portk., but is at once distinguished by
its smooth cheeks; the eyes also, in the present species, are differently formed and placed, and the glabella is
much smaller and less prominent in front. Length of glabella five lines, greatest width three lines; width at
base one line, width of cephalo-thorax seven lines; length of eyes one and a half lines, width one line; length
of posterior alar spine three lines. The Pygidium has a broad, smooth, margin or limb, in which it differs
from that of the G. longispinus, in which the segments are extended to the margin; there is a single row of
very minute granules on each segment. Width of pygidium five lines.

GRIFFITHIDES GLOBICEPS. Phil. sp.
Asaphus globiceps. Pil. Geol. York.—Griffithides globiceps. Porth. Geol. Rep.

Sp. Ch.—Cephalo-thorax semioval; glabella pear-shaped, very gibbous, globose in front; cheeks triangu-
lar, convex; eyes small, lunate, smooth, connected by a nucleus with the base of the glabella ; wings broad,
convex, with strong, imbricating, longitudinal striae; extremities acutely angular; axal and lateral lobes of the
abdomen and pygidium nearly equal, very tumid; pygidium obtusely rounded; entire surface smooth.

Specimens, with the cephalo-thorax, abdomen and pygidium in contact, are not uncommon.

GRIFFITHIDES GRANULIFERUS. Phil. sp.
Asaphus granuliferus. Phil. Geol. York.

Sp. Ch.—Pygidium obtusely rounded; length four-fifths the width; axal and lateral lobes nearly equal,
tumid; surface covered with rather distant, very minute granulations.

I have never seen this species much more than half the size of the specimen figured in the Geology of
Yorkshire: the minute, scattered granulations easily distinguish it.

GRIFFITHIDES LoNGIcEPS. Porth.
Griffithides longiceps. Porth. Geol. Rep.

Pygidium semi-oval, obtusely pointed; axal lobe large, with about ten or twelve rows of small tubercles;
lateral lobe depressed, with about eight rows of tubercles.
Ihave only seen the tail of this species.

CARBONIFEROUS FOSSILS OF IRELAND. 161

GRIFFITHIDES LONGISPINUS. Porth.
Griffithides longispinus. Porth. Geol. Rep.

I have seen very imperfect fragments only of this species; the pygidium is wider and larger than in the
G. longiceps, but similarly marked. I have not seen the head.

GRIFFITHIDES OBSOLETUS. Phil. sp.
Asaphus obsoletus. Phil. Geol. York.

This very curious species resembles the G.globiceps in general form, but has the head marked with trans-
verse, waving stria, unlike any other T’ribolite I know). Its head is very rare, only one imperfect fragment
having been seen; the pygidium figured by Prof. Phillips resembles that of the G. globiceps, and probably
does not belong to the head.

Puinuiesia cmeLATA. M‘Coy. (PI. IV. fig. 4).

Sp. Ch.—Glabella ovate, convex, rounded in front, attenuated behind, to a narrow neck; neck furrow
very strong; first cephalo-thoracic furrow deep, enclosing a semicircular, convex space, above which are, on each
side, three others shorter and more shallow; limb bordering the cephalothorax, broad, convex, when decor-
ticated, marked with twelve or thirteen fine continuous striz ; surface of cephalo-thorax closely sculptured with
a fine, scale-like granulation; neck tubercle distinct.

The only specimen which has occurred of this very interesting Trilobite is imperfect as to the cheeks, but
there are so many excellent characters to distinguish it, that the smallest fragment could be recognized. In
structure it presents some variations from the characters of the genus, as defined by Captain Portlock ; the form
of the glabella is rather that of Griffithides than Phillipsia, but it has the cephalo-thoracie furrows of the latter
genus; these furrows are four in number, or three exclusive of the semicircular basal one; that is, one more on
each side than accords with that author’s view of the genus. I have observed, however, the same number in the
P. Jonesii. Length of glabella three lines, greatest width of glabella one and a-half lines.

Puinyiesia CoLel M‘Coy. (PI. IV. fig. 6).

Sp. Ch.—Elongate, oval; length rather less than twice the width; sides parallel; cephalo-thorax smooth ;
glabella rounded in front, but not encroaching on the margin, slightly convex, constricted at the sides; cephalo-
thoracic furrows distinct, cheeks large, flattened; wings narrow, ending posteriorly in short, triangular spines;
eyes small, lunate. ‘Thorax, axal lobe rather wider than the lateral ones; each segment having a row of minute,
crowded, irregular granulations; pygidium rounded, margin broad, finely granulated, each segment having a
row of numerous, crowded, very unequal granulations, larger than those of the thorax.

This species resembles the P. Kellii, Port., but is easily distinguished by the character of the granulation
of the segments. Length eleven lines, width six lines; length of glabella four lines, width six lines. I have
dedicated this elegant fossil to the Earl of Enniskillen.

PHILLIPsIA (?) piscors. M‘Coy. (PI. IV. fig. 7).

Sp. Ch.—Pygidium semielliptical; axal lobe reaching to the margin, one-third less in width than the
lateral lobes, very convex, composed of seventeen narrow segments, the third and fourth unite in the middle
of the lobe to form one large tubercle, and towards the apex there are four or five small tubercles, irregularly
disposed; the lateral lobes have only six large, rounded segments, each terminating at the margin ina large,
rounded tubercle, and having usually between the margin and the axal lobe, two other large, obtuse tubercles,
one of these on the third and last, being largest, and probably spiniferous; besides these there are a few irre-
gular granules, especially towards the apex, all the lateral segments seem forked from nearly their origin.

T have included this very remarkable trilobite in the genus Phillipsia, Portk., although I think there can

28

162 SYNOPSIS OF THE CHARACTERS OF THE

be little doubt, if better known, it would form a genus distinct from any of those already constituted; I have
named it from the great difference in number of the segments of the axal and lateral lobes of the pygi-
dium. Length of pygidium three lines, width four and a half lines, width of axal lobe one line.

PHILLIPSIA GEMMULIFERA. Phil. sp.
Asaphus gemmuliferus. Phil. Geol. York.
Sp. Ch.—Pygidium obtusely rounded, narrow; with three nearly equal, convex lobes, each lobe with six
longitudinal rows of small tubercles.
This species strongly resembles the P. truncatula, but is constantly smaller and more convex. Length
of pygidium five lines, width five lines.

Puituiesia Jonesu. Portk.
Phillipsia Jonesii. Porth. Geol. Rep.

Sp. Ch.—Longitudinally oval, twice as long as wide; glabella one-third the entire length, very broad,
depressed, obtusely rounded in front, contracted in the middle; eyes very large, reniform, more than half the
length of the glabella; cheeks small, narrow, slightly convex; surface covered with minute, rather distant, im-
pressed puncta; abdomen and pygidium smooth.

This species is easily recognized by its very broad, depressed glabella, which is somewhat hour-glass
shaped, being remarkably contracted in the middle; many specimens are found rolled up. Length of cephalo-
thorax four lines, width five lines.

PuimurrsiA Kettu. Portk.
Phillipsia Kellii. Porth. Geol. Rep.

This pretty little species is intermediate between the P. truncatula and P. Jonesii ; it is about the size
of the latter species, but resembles the former in the tuberculation of the pygidium, which is also more obtuse
at the extremity than in that species; there are six rows of granules on each lobe of the pygidium. The head

resembles that of the P. Jonesii, but is longer in proportion to the width, has smaller eyes, and the glabella
has more nearly parallel sides.

Puitiresta Macoyu. Portk.
Phillipsia Macoyii. Porth. Geol. Rep.

The only specimen which has occurred of this species I collected myself from the carboniferous limestone
of Kildare; it was lent to Captain Portlock for his Monograph of Irish Trilobites, as I conceived it to be not
only a new species, but the type of a new genus. I am still inclined to think it cannot be ranked with any
known genus; the very small size of the glabella, and large size of the eyes, distinguish it from the most
nearly allied, and from Phillipsia, with which Captain Portlock has ranked it, it is distinguished by the want
of the cephalo-thoracic furrows. As I have, however, no means of examining the specimen now, I cannot
characterize it. Length of cephalothorax two lines, width three lines.

PHILLIPsiA MUCRONATA. MM Coy: (Pu TV. tis! 5):
Sp. Ch.—Pygidium semi-elliptical, terminating posteriorly in a short, mucronate, obtuse pomt; axal lobe
nearly as wide as the lateral ones; about fifteen axal and nine lateral seements; surface smooth.
This is the only Trilobite I know of in the Mountain Limestone with a mucronate or pointed tail.
Length of pygidium four lines, width five lines.

PHILLIPSIA QUADRISERIALIS. ‘Coy. (PI. IV. fig. 8).
Sp. Ch.—Pygidium semi-oval, slightly wider than long; of fifteen axal and twelve lateral segments; each

lobe bearing four rows of large tubercles; limb narrow, flattened, smooth.

CARBONIFEROUS FOSSILS OF IERLAND. 163

This species is distinguished from the P. truncatula, by having but four instead of six rows of tubercles
on each lobe; it is also very much smaller and rather more pointed posteriorly. The same character distin-
guishes it from the P.gemmulifera, P. Kellii, P. longispina, &c. Length of pygidium four lines, width five
lines.

PHILLIPSIA TRUNCATULA. Phil. sp.
Asaphus truncatulus. Phil. Geol. York.—Phillipsia ornata. Porth. Geol. Rep.

Sp. Ch.—Pygidium large, obtusely pointed, lateral lobes flattened ; mesial lobe narrower, tumid; each lobe
with six longitudinal rows of rounded tubercles.

I have not seen either the head or abdomen of this species. Length of pygidium nine lines, width eleven
lines.

Diruyrocaris. Scouler. 3

As my friend Dr. Scouler has not as yet fully published his views concerning this very important and cu-
rious genus, I shall not offer any observations upon it.

Diruyrocaris Corer. Portk.
Dithyrocaris Colei. Portk. Geol. Rep.

Sp. Ch.—Longitudinally oval; anterior end narrow, having a shallow, rounded sinus in front, posterior
end broader; margins sigmoidally curved, forming an acute sinus towards the centre; sides terminating in acute,
angular, flattened spines; the mesial ridge strongly crenated ; lateral ridges almost as large as the mesial one, and
similarly crenated ; short, sigmoidal, anterior ones also similar ; margins of the valves obliquely striated; surface
otherwise perfectly smooth.

This large species is very closely allied to the dArgas tricornis, Scouler. Taking one half of the shield, or
one valve, its length is about twice and a half the width. Length of single valves three inches seven lines,
width one inch six lines.

DITHYROCARIS ORBICULARIS. Portk.
Dithyrocaris orbicularis. Portk. Geol. Rep.

I have only seen a few fragments, probably of this species; along with the last, it is distinguished by its
nearly circular outline, and its tuberculated lateral and mesial ridges and margin.

Diruyrocaris Scoutertr M‘Coy. (Pl. XXIII fig. 2).

Sp. Ch.—Length of expanded pair of valves very slightly exceeding the width, surface smooth; central
and lateral ridges transversely wrinkled; frontal notch nearly as deep as wide, rounded. Valves, when spread
flat, forming a nearly orbicular shield, the length very slightly exceeding the width, and having a deep, rounded
notch in front; central ridge or hinge strong, rounded, regularly marked with transverse wrinkles; lateral
ridges marked with irregular, flat, scale-like undulations; intermediate short ridges nearly straight, slightly
bent towards the central ridge above, and towards the lateral ridges below; surface smooth ; margin of the valves
narrow, fringed or obliquely striated, immediately within which, on the lateral margins, is a plain, rounded
ridge, divided longitudinally by a nearly mesial sulcus; it 1s close to, and parallel with the outer margin for
about the upper half of its length, then gradually turning in towards the lateral ridge, where it widens; tail ex-
actly equalling the body in length, terminating as usual in three spines of nearly equal length, the central one
triangular, marked with very fine, oblique stria, meeting at an acute angle on the central ridge; two lateral
spines rounded, coarsely sulcated longitudinally. Width of the expanded pair of valves one inch four lines,
length to the tip of posterior spine one inch five lines, length of central spine of tail one inch.

164 SYNOPSIS OF THE CHARACTERS OF THE

Diruyrocaris TENvISTRIATUS. AfCoy. (Pl. XXIII fig. 3).

Sp. Ch.—Valves elongate, ovate, rounded anteally, obtusely pointed retrally, convex ; mesial ridge large, run-
ning nearly the entire length of the valve; two smaller ridges close to, and parallel with the inner margin; about
one-fifth of the length from the anterior end, and situate between the mesial and internal ridges, there is a
short sigmoidal ridge, and a fifth one at the anterior end defines, for a short way, the line which separates the
flat, external margin from the convex part of the valve; surface finely and regularly striated longitudinally.

This species differs from all others of the genus, in the want of the retral spine to the valve; it is also much
more convex than any of its congeners; fragments may be discriminated by the regularity and fineness of the
strie. Length of the valve one inch, width five lines.

Entomoconcuus. MM‘ Coy.
Gen. Ch.—Shell bivalve, globose ; depth from the dorsal to the ventral margin exceeding the length; abdo-
minal margin most convex ; hinge auriculated at each end, and with two small, beak-like folds nearly in the centre.

Entomoconcuus Scoutert. M‘Coy. (Pl. XXIII fig. 4).
Entomoconchus Scouleri. M‘Coy, Jour. Geol. Soc. Dub.—Cytherina Phillipsiana. Koninck. Crus. Bel.

Sp. Ch.—Globose ; hinge in the direction of the shortest diameter of the shell, having at each end a short,
square, or slightly rounded ear; one end more globose than the other, the straightest extremity having a slightly
developed auriform process, resembling those of the hinge; surface very finely granular.

A description of this fossil has already been published in the Transactions of the Geological Society of
Dublin; it was originally figured by Prof. Phillips in the Geol. York., but not named or described; subsequently
to the period at which I described it, Koninck figured and described it under the name of Cytherina Phil-
lipsiana. Ihave retained my own name, not so much from its priority, as because I do not think it can be
well referred to Cytherina; each valve, besides the small, square ears, has two obtuse umbones close to the
hinge-line; the general form reminds us of shells of the genus Lima, as the recently discovered genus, Jsaura,
puts on in the same family the appearance of a Cyclas. Those shell-like Entomostraca are of the greatest
interest, many of the minute bivalves suffered to remain in genera of Conchifera belonging almost certainly to
this class. Length eleven lines, width nine lines. ;

Darunia PRIMAVA. M‘Coy. (Pl. XXIII. fig. 5).
Daphnoides (?) Hd. Trans. Roy. Soc. Ed.

Sp. Ch,—Longitudinally oval, compressed; without tail; head forming a short, obtusely pointed beak,
curved downwards.

I believe this is the first instance in which the genus Daphnia has been observed in the fossil state; the
present species is not very uncommon in some localities; like one or two of the recent species, it is without the
posterior mucronate point, possessed by the majority of the genus; the head forms a very distinct, but short
beak; but I have as yet seen no traces of its eye, although the shell on that portion of the surface is well pre-
served; the sides are but slightly convex. Length one and one-third lines, depth three-fourths of a line.

Barrpia. M‘Coy.

Gen. Ch.—Shell elongate, fusiform, suddenly tapering at both ends; a very short proportion of the valve
overlaps the abdominal margin. 1
The fossils of this genus are readily distinguished by their lengthened, ovate form, and ends suddenly taper-
ing to blunt, recurved points; they are all of a small size. I have named the genus in honour of Mr. Baird,

the able investigator of the living British Entomostraca.

Bairpra curtus. M‘Coy. (Pl. XXIIL fig. 6).
Sp. Ch.—Length twice and a half the depth; dorsal margin very convex ; abdominal margin nearly straight.
This is a much shorter and more gibbous species than the next. Length one line.

CARBONIFEROUS FOSSILS OF IRELAND. 165

Barrpia GRAciuis. MM‘Coy. (Pl. XXIII fig. 7).

Sp. Ch.—Length three and a half times the depth; dorsal and abdominal margins parallel.

The diameter is about two-thirds the depth; the abdominal margin is convex at both ends, and concave
im the middle; the dorsal margin is concave at both ends, and convex in the middle, they are consequently
nearly parallel; both ends are alike. Length half a line.

CyTHERE AMye@paLina. M‘Coy. (Pl. XXIII fig. 8).

Sp. Ch.—Length rather more than twice the depth; one end small, rounded, submucronate; the other
much larger, obtusely rounded; valves convex; surface smooth.

This species has much the shape of the C. excavata, M‘Coy, but is more slender, has more unequal ends,
and is entirely without marks or impressions of any kind. Length half a line. Common.

CyTHERE arcuaTa. M‘Coy. (Pl. XXIII fig. 9.)

Sp. Ch.—Slender, rounded, twice as long as deep, arcuate, convex, the dorsal margin very convex, ventral
margin nearly equally concave; surface smooth, without markings.

This little species is very common in the carboniferous shales, and although rarely well preserved, is easily
recognized by its lengthened, curved form; it differs from Bairdia gracilis, M‘Coy, and the allied species, by its
simple, obtusely rounded extremities. Length about halfa line.

CYTHERE BITUBERCULATA. M‘Coy. (PI. XXIII. fig. 10).

Sp. Ch.—Twice and a half longer than deep; ventral edge long, straight; back but slightly convex; both
ends nearly equally rounded; sides flattened ; each valve with two very large, rounded tubercles, situated rather
more than their own diameter, one from the anterior, the other from the posterior end.

This very distinct and beautiful species is common in one or two localities; it is easily known from the
other species I have described, by the two large tubercles on each valve. Length one-third of a line.

Cytuere costata. M‘Coy. (PI. XXIII. fig. 11).

Sp. Ch.—Ovate, rounded, gibbous; abdominal margin very convex; ends obtusely rounded; the anterior
slightly narrower; a deep circular depression in the centre of each valve, and each side ornamented with four,
longitudinal, slender ridges, and one following the curve of the abdominal margin and ends; three or four
obtuse, rounded tubercles at the anterior end.

I have seen several specimens of this very distinct and beautiful species, which is, however, one of the
rarest and most solitary of the genus. It is easily distinguished from all others by its beautifully costated sides ;
the number of tubercles at the anterior end is also remarkable. Length half a line.

CytTuere cornuta. M‘Coy. (Pl. XXIII. fig. 12).

Sp. Ch.—Shell sub-rhomboidal, gibbous; an obtuse spine near the centre of the abdominal margin of each
valve.

This is distinguished at a glance from the C. spinigera, M‘Coy, by having the spiniform tubercle in the
middle or nearly so, of the abdominal margin; the posterior end is obtusely rounded, while the anterior
end gives a slight obliquity to the contour of the shell; the dorsal outline is gradually curved, the abdominal
somewhat undulated, but without a sinus. This shell is most inflated at the back, and gradually diminishes in
diameter towards the abdominal edge; the sides are not, however, concave, one valve overlaps the other

il

166 SYNOPSIS OF THE CHARACTERS OF THE

for a small space beneath. This species bears a considerable resemblance to the Cypris spinigera, Sow., but
that shell is an inhabitant of the Wealden rocks, and truly belongs to the fresh water genus, Cypris, while this
is a marine shell, and consequently not of that genus. A comparison of the figures of the two species will
exhibit numerous differences. Total length one line; the diameter is two-thirds the depth; depth a little more
than half the length. Not common.

CyTHERE ELONGATA. M‘Coy. (Pl. XXIII. fig. 13).

Sp. Ch.—Three times as long as deep; dorsal and ventral margins nearly parallel, very slightly curved ;
ends equal, rounded; sides convex, smooth, one small tubercle near the anterior end.

The great length in proportion to the depth, is so remarkable in this species, that although very small, it
is easily distinguished by the naked eye. It is very common in the shales of certain localities; but, from the
want of a specific name, has not been heretofore noticed. Length half a line.

Cyruere excavaTa. M‘Coy. (Pl. XXIII fig. 14).

Sp. Ch.—Ovate, convex; length nearly twice the depth; one end broadly rounded, the other rounded,
but narrower; valves smooth, a deep circular hollow in the middle of each, nearest the narrow end; surface
smooth.

At first sight this species resembles the C. impressa, M‘Coy, but is distinguished by the larger size

of the depression in the valves, their more uniform convexity, and the total absence of tubercles. Length about
half a line.

CyTHERE GipperuLA. M‘Coy. (PI. XXIII fig. 25).
Sp. Ch.—Gibbous; back semicircular; ventral margin short, straight; ends very obtusely rounded; each
valve swelled in the middle into a large, undefined, rounded gibbosity.

This species occurs in great numbers in the shale of some localities, it is chiefly remarkable for the large
hump or protuberance in the middle of each valve. Length half a line.

Cytuere Hissertu. M‘Coy. (Pl XU fig. 15).

Sp. Ch.—Oblong; depth two-thirds the length ; ventral margin nearly as long as the shell, prominent ;
ends equal, subtruncate, rounded; valves convex, compressed towards the ventral margin; surface smooth.

This is the largest species of Cythere I have met with in the Irish Paleozoic rocks, being frequently
upwards of a line in length. It resembles the C. inflata, M‘Coy, but is much less gibbous, has a longer and
more prominent ventral margin, and less pointed ends; the dorsal margin is also less convex in the present
species, giving it something of an oblong, square outline.

This I believe to be the species figured by Captain Portlock as the Cypris Scotoburdigalensis of Hibbert,

but an examination of several Burdiehouse specimens induces me to give it, at least provisionally, a distinct
name.

CyTHERE impressa. M‘Coy. (Pl. XXIII fig. 16).

Sp. Ch.—'Twice as long as deep, gibbous; ends rounded, anterior slightly larger than the posterior ; ventral
margin nearly straight for about half its length, suddenly convex at the anterior end; sides of the valves smooth ;
a deep, narrow depression close below the dorsal margin, at equal distance from each end, with a small tubercle
placed on its anterior edge.

This species is very common in the slates and shales of several districts; it is easily recognized by its
unequal ends, and, where the surface is preserved, by the deep, impressed puncture in the middle of the dorsal

margin, and its accompanying tubercle; the valves are most gibbous at the anterior side of the depression.
Length about half a line.

CARBONIFEROUS FOSSILS OF IRELAND. 167

CyTHEerE INFLATA. M‘Coy. (Pl. XXIII. fig. 17).

Sp. Ch.—Shell gibbous; anterior and posterior ends nearly alike, anterior a little larger; diameter from
the most convex part of one valve to that of the other, five-sixths of the depth, measured from the centre of the
dorsal to the centre of the abdominal margin; depth two-thirds of the length; abdominal margin of the left
valve overlaps. Length from one to two lines.

This is the largest, as it is likewise the most abundant species of Cythere found in the mountain limestone
of Ireland. Its most ordinary size is about a line and a half long, and one line from the dorsal to the abdomi-
nal margin; the back is much and regularly curved, greatly inflated, and marked along the centre by a groove
or suleus, which points out the situation of the hinge; towards the abdominal margin it suddenly becomes com-
pressed, the abdominal margin itself is straight, without any sinus, and presenting a very small, obtuse, radicle-
like projection; the abdomimal portion of the left valve overlaps the other very distinctly.

This species abounds most in dark, fcetid limestones, but it is rare in the light-coloured limestones, where

the following species supplies its place.

CyTHERE INoRNATA. M‘Coy. (Pl. XXIII fig. 18).

Sp. Ch.—Compressed ; diameter one-half the depth; sides slightly convex; shell plain.

This is a very small species; rarely exceeding half a line in length, it bears a great resemblance to the
young of the C. cornuta,M‘Coy, in general form, but wants the characteristic spines of that shell, and the sides,
instead of being concave, are convex. It is also much more compressed than the C. inflata, M‘Coy, which it re-
sembles in the want of'spines. In that shell the depth is less than the diameter, while it is double the diameter

in this species. Very common in several localities.

Cyruere optonca. M‘Coy. (Pl. XXIII fig. 22).

Sp. Ch—Oblong, very gibbous; length rather less than twice the depth; dorsal and ventral margins
slightly curved, parallel; ends almost at very obtuse, rounded; surface smooth, without ornament.

This is rather a large species, having, to the naked eye, an oblong square form; the valves have their
greatest convexity in the middle, while in the C. Hibberti, M‘Coy, and C. inflata, M‘Coy, which it most re-
sembles, the greatest convexity is along the dorsal margin; from those species it is likewise distinguished by
its greater length and the equal curvature or parallelism of the dorsal and ventral margins. Length about one
line. Common.

CyTHERE orBicuLARIs. M‘Coy. (Pl. XXIII. fig. 19).

Sp. Ch.—Nearly orbicular, depressed, length very slightly exceeding the depth; valves flattened, gibbous
in the middle, smooth.

This is comparatively a large species, nearly equalling the C. inflata and C. Scotoburdigalensis in size, from
both of which it is easily known by its proportionate shortness, the flatness of the valves, and their central gib-
bosity ; from the C. gibberula, which it resembles in the central gibbosity of the valves, it is distinguished, as
in the other cases, by the remarkable shortness in proportion to the depth. Length one line.

Cytuere pusitta. M‘Coy. (Pl. XXIII fig. 20).

Sp. Ch—Oval, length but, slightly exceeding the pee very gibbous; ends rounded; ventral margin
short; surface smooth.

This is the smallest species of Cythere which I have ei in the Paleozoic rocks; it has no very tan-
gible characters, yet from its great abundance it becomes important; it is more nearly spherical than any of the

168 SYNOPSIS OF THE CHARACTERS OF THE

others; it most closely resembles the C. inornata, M‘Coy, but is more gibbous, and has more nearly equal ends.
Length about one-third of a line.

CyTHErE scutuLum. (M‘Coy. (Pl. XXIII. fig. 21).

Sp. Ch.—Orbicular, compressed, smooth; sides flat; ventral margin about one-third the length of the
shell; the ends equal, projecting below the ventral margin.

This species approaches the C. orbicularis, M‘Coy, in shape, but is well distinguished by the form of its
ventral margin, and the perfect flatness of its sides, the sides of C. orbicularis, M‘Coy, being very gibbous or
obtusely conical. Length one line.

CyTHERE sprnicerA. M‘Coy. (Pl. XXIII fig. 23).

Sp. Ch.—Shell somewhat reniform, sides slightly concave; one spiniform tubercle close to the end on each
valve; a slight abdominal sinus.

This species has both ends alike, and the sides a little concave; there is a very small abdominal sinus,
while the back is much and regularly curved; the portion of the valve which overlaps is much thickened ; in
this species the two tubercles are entirely beyond this portion, while in C. cornuta, they are nearly in the
centre. Length from one line to a line and a quarter; diameter two-thirds the depth; depth two-thirds the
length.

CYTHERE TRITUBERCULATA. M‘Coy. (Pl. XXIII. fig. 24).

Sp. Ch.—Oblong, length rather more than twice the depth, convex; both ends equal, rounded; dorsal
and ventral margins nearly parallel, each valve with three small, round, nearly equidistant tubercles, one of
which is much closer to the ventral margin than the other two.

This species, in addition to its lengthened, regular form, is easily distinguished from its congeners by the
three tubercles on each valve. Length half a line.

,

ANNELIDA.

The Annelida, or red-blooded worms, are the least highly organized group of the Annulosa, or articulated
animals; the forms found in the carb. limestone belong to Cuvier’s order Tubicola, or those sedentary species
having the gills attached to the head, and inhabiting a tube, sometimes shelly, as in Serpula, sometimes nearly
membranous, or formed of agglutinated grains of sand, as in Terebella or Sabella.

SerpuLa. Linn.
Gen. Ch.—Tubular, gradually widening towards the aperture ; irregularly attached; aperture round; edge
simple.
SERPULA (?) COMPRESSA. Sow.
Serpula compressa. Sow. Min. Con.
Sp. Ch.—Tube thick, perlaceous (?) rapidly tapering, flexuous; section elliptical.

The examples I have seen of this species seem more allied to Serpulites than to Serpula; the pearly or

glistening appearance of the surface more nearly resembling the former than the latter genus. Diameter four
lines.

CARBONIFEROUS FOSSILS OF IRELAND. 169

SERPULA HEXICARINATA. M‘Coy. (Pl. XXIII. fig. 28).

Sp. Ch.—Elongate, slightly flexuous, hexagonal ; sides nearly equal, smooth, flat; a narrow, rounded, pro-
minent keel on each of the angles.

This species is easily distinguished from any of the other Palzozoic Serpule, by the hexagonal form of the
tube, and the six narrow, rounded keels on the angles. Length usually about two inches, width half a line.

SERPULA PARALLELA. M‘Coy. (Pl. XXIII. fig. 30).
Serpula socialis. Gold. Portk. Geol. Rep.

Sp. Ch.—Tubes very slender, cylindrical, smooth, grouped parallel to each other in bundles; tubes one-
fourth of a line in diameter.

This curious species differs from all the Serpule with which I am acquainted, in being perfectly smooth,
and without the irregular flexuosity in any part of the tubes, which we commonly see in the other species of the
genus; the tubes are parallel to each other, forming masses three or four inches long, and one inch in thickness.
When preserved in shale they are usually yellowish and semi-transparent, probably owing to their mode of
conservation ; in limestone they are white and opaque. It is exceedingly constant in its characters; as it 1s
certainly not identical with the Serpula socialis, Gold., of the cretaceous period, it seems best to give it a dis-
tinctive name.

SERPULA scALARIS. M‘Coy. (Pl. XXIII. fig. 29).
Sp. Ch.—Cylindrical, very slowly tapering, tortuous; shell thick ; surface with large imbricating, transverse
rings.
This species is rendered remarkable by the large, regular, transverse rings on the surface of the tube, which
is very tortuous. Diameter two lines.

Sprroreis. Lam.
Gen. Ch.—Discoid, spirally coiled, whorls round; attached by the under side.

SPIRORBIS CAPERATUS. M‘Coy. (Pl. XXIII. fig. 26).

Sp. Ch.—Discoid, whorls hardly two, very rapidly enlarging, round, strongly wrinkled concentrically.
I have only seen one specimen of this pretty little shell attached to a species of Fenestella; the strongly
wrinkled surface will distinguish the species.

Sprrorpis GLoposus. M<Coy. (PL IV. fig. 10).

Sp. Ch.—Subglobose, slightly compressed, smooth; volutions concealed by the last whorl; back broad,
rounded; umbilicus very small.

This very gibbous species differs from the S$. omphalodes, Gold., in the small size of the umbilicus, and
the completely concealed volutions; it most nearly resembles the S. valvata of the Muschelkalk. Diameter
one line, thickness half a line.

SprrorBis INTERMEDIUS. M‘Coy. (Pl. IV. fig. 9).

Sp. Ch.—Discoid, flattened; sinistral; whorls two and a half, round, nearly equal in thickness throughout ;
a few distant, irregular, ring-like thickenings.

This species is intermediate between the §. ammonia and the S. omphalodes, having the compressed
form, very gradually increasing whorls, and obscurely annulated surface of the former, with a smaller number
of whorls, besides which, it differs from both in being sinistral. Diameter one line, thickness one-fourth of a
line.

2U

170 SYNOPSIS OF THE CHARACTERS OF THE

Sprrorzis MinutTus. Portk.
Spirorbis minutus. Portk. Geol. Rep.

I have not seen good specimens of this shell; those on the specimens of Dithyrocaris Colet which I have
examined, being very indistinct; it seems, however, a very good species. I have not seen it except in this situ-
ation. ‘There are only about two turns in the spire: diameter about one-fifth of a line.

SPIRORBIS OMPHALODES. Gold. ?
Serpula omphalodes. Gold. Pet. ?

On certain shale-plants are found abundance of a little shell referred by Captain Portlock to the above
species. The Irish specimens are perfectly flat on the attached side,smooth, and having two and a half or three
turns in the spire; the mouth semicircular. Goldfuss’s characters do not exactly agree with those, I have therefore
marked the reference with a doubt.

SprrocLtypuus. Lam.

Gen. Ch.—Discoid; spirally coiled; parasitic; forming a deep groove for itself in the surface of shells.

SPIROGLYPHUS MARGINATUS. J/‘Coy. (Pl. XXIIL fig. 27).

Sp. Ch.—Discoid; volutions hardly two; upper side rounded; attached side flat; externally bordered by
a broad, flat keel; surface smooth. Parasitic on various shells in one or two localities.

SERPULITES cARBONARIUS. M‘Coy. (Pl. XXIII. fig. 32).

Sp. Ch.—Tube small, narrow, shelly; terminating posteriorly by two lengthened, cylindrical tubes, the
prolongation of the lateral, thickened ridges.

This remarkable species is intermediate in the texture of its tube, between the S. longissimus, Sow., and
S. membranaceus, M‘Coy, being more delicate than the former, but much more testaceous than the latter; it
is, however, greatly inferior to either of them in size, the most usual diameter of the compressed tube being one
or one and a half lines, and the largest specimen which has, as yet, fallen under my observation was barely two
lines in width; the forked, posterior termination is a new and important character, which, however, I believe
to belong to the whole genus, rather than to characterize the present species. Itis formed of two long testaceous
tubes, bordered on the inside of their base by a membranous prolongation of the principal tube.

My friend, Dr. Scouler, has recently shewn me specimens of this species, collected by himself, from the
Scotch carboniferous shale.

SERPULITES MEMBRANACEUS. M‘Coy. (Pl. XXII fig. 31).

Sp. Ch.—Tube elongate, curved, membranaceous; abdominal and dorsal (?) margins thickened.

The extraordinary genus Serpulites, hitherto thought so characteristic of the Silurian rocks, as to distin-
guish the slates of that period from those of the carboniferous system, has recently occurred in some abundance in
the shales of the carboniferous period; the species, however, appear to be distinct from those in the Silurian rocks.
The present species is of great size, probably exceeding that of the S. longissimus ; its substance, however, instead
of being decidedly shelly as in that fossil, is excessively thin and membranous, so that the smallest fragments
of the two species could be easily discriminated. A very interesting fact is shewn by our figure, namely, that
two opposite points of the circumference of the tube were really thickened, forming two opposite, longitudinal

ridges (or tubes ?) and that this appearance is not due to pressure. General width of the compressed tube seven
lines.

CARBONIFEROUS FOSSILS OF IRELAND. 171

SABELLA ANTIQUA. M‘Coy. (PI. IV. fig. 11).

Sp. Ch.—Tube composed of very fine grains, cylindrical for about one inch and a half, gradually
tapering at one end; diameter of tube about one line.

This curious fossil occurs in considerable numbers in the shales of several districts in Ireland. When
the specimens are well preserved, they shew the finely granular, arenaceous tube, with, in many instances, its
smooth, glossy, membranous lining; the specimens are usually more or less curved, particularly towards the
smaller end. They are usually about two or two and a half inches long.

ECHINODERMATA.

The Echinodermata are the most highly organized of the Nematoneura, and form an exceedingly well-de-
fined group.

Some of them, as the Sipunculide, resemble worms in their external appearance, being cylindrical, soft,
and without feet; their internal structure, however, is perfectly that of the Echinodermata. Next come the
Holothurie, which, though still without a caleareous covering, approach very nearly in structure to the Echine;
they are for the most part oval and smooth, with five rows of ambulacra, or rows of tubular suckers or feet (some-
times scattered over the body) the head is surrounded with beautifully pinnate, leaf-like gills. The Echini differ
from those in having the entire body enclosed in a hard, calcareous, spheroidal case, having five narrow ambu-
lacra, each composed of two rows of small, pentagonal plates, each plate perforated for the passage of two sets of
tubular, foot-like suckers; between the ambulacra are five broader spaces, each composed of two rows of large,
pentagonal, imperforate plates, closely set with sharp spines, which both serve as a defence and assist in locomo-
tion; the mouth is furnished with a complex and powerful dental apparatus, which does not occur in any of the
other Echinoderms. The respiration is principally effected by the admission of water to the interior, where it
is made to pass in currents over the lining membrane of the shell and the surface of the intestines, by means of
the cilia with which they are covered. Following them, we have the Astertade or star fishes, in which the
general form is depressed and divided into five or more rays, the under side of each of which is hollowed into an -
ambulacral groove, analogous to the ambulacra of the Echinide, and pierced for the passage of similar foot-like
suckers; the tip of each ray exhibits a small red point, which is considered by Ehrenberg to be a true eye.
The external integument is coriaceous and covered with hard, calcareous granules, plates, or spines; the mouth is
central and without teeth. By means of the genus Comatula we pass at once from the Asteriade to the Crinoidea,
which form the lowest group of the Echinodermata.

Patacuinus. Scouler. MSS.

Gen. Ch.—Spheroidal; ambulacra composed of two rows of pentagonal plates, each perforated by two rows
of pores; anambulacra composed of two rows of pentagonal, and three or more rows of hexagonal plates; plates
covered with spiniform tubercles, destitute of central ligament ; anus dorsal, central; ovarian plates as in
Echinus ; mouth ventral, central.

The above name was provisionally given by Dr. Scouler to a specimen in the Collection of the Royal
Dublin Society, and to another in the Collection of the Rev. Mr. Fox; they were exhibited at a meeting of
the Geological Society of Dublin under those names; at that time the specimens were obscured by adhering
matrix, and considered unique; a satisfactory examination was, therefore, impossible, and in consequence no
characters could be given to separate them from the other recent or fossil genera; the accession of additional

172 SYNOPSIS OF THE CHARACTERS OF THE

specimens, and the discovery of two more new species from the shales of the north and south of Ireland, have
enabled me to give the above generic characters. I have adopted the name proposed by Dr. Scouler. Most of
the Echinide have the interambulacral spaces composed but of two rows of large, pentagonal plates; in the pre-
sent genus, on the contrary, it is composed of from five to seven rows of plates; the spmiferous tubercles and
ambulacra have the same character as in Lechinus.

PaLa@cuinus ELEGANS. M‘Coy. (Pl. XXIV. fig. 2).

Sp. Ch.—Ovate ; dorsal end pointed; ventral end obtuse, rounded; ambulacra large, convex; interam-
bulacra composed of two rows of pentagonal, and three rows of hexagonal plates; interambulacral plates mam-
millated, and covered with very minute spiniferous tubercles, width of the lateral interambulacral plates equal
to five ambulacral ones.

This species is readily distinguished from the P. ellipticus, by its pointed, superior extremity, the mam-
millated surface of the plates, independent of the spiniferous tubercles, and the greater proportional size of the
ambulacral plates. Length about two inches.

PALZCHINUS ELLIPTICUS. Sc. MSS. (Pl. XXIV. fig. 3).

Sp. Ch.—Elliptical ; ventral and dorsal ends equal; ambulacra prominent, convex, and having two rows
of pores on each side; interambulacra composed of two rows of pentagonal, and three rows of hexagonal plates ;
plates evenly convex, regularly marked with numerous minute tubercles, nearly in quincunx; the width of
one pentagonal, lateral, mterambulacral plate equal to seven ambulacral ones.

This species is distinguished by its regular elliptical form, and the small size of its ambulacral plates, seven
of which are only equal in width to one of the interambulacral ones. Length two inches, width one inch eight
lines.

Patzcuinus cicas. M'Coy. (Pl. XXIV. fig. 4).

Sp. Ch.—Orbicular, depressed; interambulacra composed of six rows of plates ; four rows of pores on each
side the ambulacra; seven ambulacral plates equal to the width of one of the lateral anambulacral ones ; tubercles
large, equal, each surrounded by a ring.

This is by far the largest species of the genus ] have met with. The above specific characters will distin-
guish it readily from its congeners; the spiniferous tubercles on the plates are nearly equal in size, and disposed
regularly in quincunx; each tubercle is of considerable size, convex, imperforate, and surrounded by a narrow,
elevated ring ; the space between the tubercles is smooth; the ambulacral plates bear tubercles in this species,
as well as the interambulacral, a character which may be useful in distinguishing fragments from the other spe-
cies. Length of a hexagonal plate from the middle of the interambulacra four lines, width six lines.

Panmcunus (2) Kontan. M'Coy. (Pl. XXIV. fig. 19).

Sp. Ch.—Plates, with numerous, irregularly placed, large, compressed tubercles, between which are nume-
rous, small, simple tubercles, very irregularly disposed.

This species is more nearly allied to Echinus, in the character of its tuberculation, than any other of the
Palechini ; in the latter genus the tubercles are uniform, or nearly so, in size and structure, while the present
species resembles Echinus, in having two distinct sets of tubercles, the smaller being greatly more numerous.
The surface in the specimens I have examined was reticulated with very fine lines, apparently the traces of
muscular action of the integument for moving the spines.

PaLacuinus spuericus. Scouler. MSS. (Pl. XXIV. fig. 5).

Sp. Ch.—Spherical; anal and oral ends equal; ambulacra prominent, convex, with two rows of pores on
each side; interambulacra composed of two rows of pentagonal, and im some cases four, in others five rows of

CARBONIFEROUS FOSSILS OF IRELAND. 173

hexagonal plates; one of these rows always becomes obsolete before reaching the anus, thus producing an irre-
gularity in the shape of the adjoining plates; surface of the plates irregularly studded with minute tubercles.

This fine species is distinguished by its spherical form, and the number and irregularity of the interambu-
lacral plates. Iam not acquainted with any other Echinite in which the interambulacra are dissimilar; in the
present species, however, some of the interambulacra have six rows of plates, while others have seven.

Ecurnocrinvs. Agass.

Gen. Ch.—Interambulacra composed of three or more rows of plates, those on each side, next the ambu-
lacra, pentagonal, those of the intermediate rows hexagonal, as in Palechinus 5 each plate having in the centre
one large, perforated tubercle, surrounded by an elevated ring, as in Cidaris, each of which tubercles bears a
large, mobile, generally muricated spine.

It is a singular circumstance that, except Professor Agassiz, every author who has hitherto treated of the
Echinodermata of the mountain limestone, should have referred the hexagonal plates with the above characters
to the genus Cidaris, when a glance at the recent or Oolitic Cidarites, would be sufficient to shew that in their
entire framework there is not one hexagonal plate, both the ambulacra and interambulacra being composed
each of two rows of pentagonal plates only, while in the present genus, as in Palechinus, their interambulacra
must have been composed of more than two rows, as is obvious from their hexagonal form: the large, perforated
tubercle, however, is precisely in accordance with that of the true Cidaris, as is also the mode of attachment
and general character of the large spines with which both genera are armed. Thus, as we have seen, the Echini
of the mountain limestone to differ remarkably as a group from the Cainozoic and Mesozoic genera, in the com-
plexity of their interambulacra; so do we find the Cidarites of the Paleozoic rocks to differ in the same cha-
racter, both from the recent and newer fossil forms: while the relation which the recent Cidarites bear to the
recent Echini is precisely equivalent to that which Echinocrinus holds to Palechinus. 1 had long ago distin-
guished this genus in my MSS. under the name of Archeocidaris, subsequently Professor Agassiz announced
his intention of forming the genus Hchinocrinus for the Cidaris Neri, &c.

Ecurnocrrnus Munsterranus ? Koninck. sp. (Pl. X XVII. fig. 2).

Sp. Ch.—Spines cylindrical, with about twenty-three longitudinal, oppositely muricated ribs.

This beautiful little spine is at once distinguishable from any other living or fossil species with which I am
acquainted, by the great number of its minutely denticulated ribs; itis very rare. The fragment figured mea-
sures half an inch in length; breadth two lines. The figure I have given was lithographed nearly three years
ago, previous to its description by M. de Koninck.

ECHINOCRINUS GLABRISPINA. Phil. sp.
Cidaris glabrispina. Phil. Geol. York.

I have seen two or three smooth spines of Hehinocrinus about one inch in length, and tapering gradually
to a point, which, I suppose, are referrible to this species.

ECHINOCRINUS TRISERIALIS. M‘Coy. (Pl. XXVI. fig. 1).

Sp. Ch.—Large mobile spines, triangular; each of the angular ridges armed with a row of strong, tooth-
like spines; intervening spaces smooth.

The spines of this species differ from all I am acquainted with, in having but three longditudinal rows of
spines, or denticulations, the other species of the limestone having four or five rows; the portions of the spine
not muricated are smooth in this, but strongly striated longitudinally in the other species; it also differs in its
triangular form, the sides being nearly flat and almost equal. Length of specimen figured, imperfect at each
end, one inch eight lines, diameter one and a half lines.

21x

174 SYNOPSIS OF THE CHARACTERS OF THE

Ecurnocrinus urn. lem. sp. (Pl. X XVII fig. 1).
Echinus. Uye’s Hist. Ruth—Cidaris Uri. lem. Brit. Anim.—Cidaris Benburbiensis. Porth. Geol. Rep.

Sp. Ch.—Spines with their lower third finely striated longitudinally ; upper two-thirds’ with about five
or six longitudinal, alternating rows of short, strong spies. Plates having the central perforated tubercle sur-
rounded by asingle ring; margin with rounded radiating ridges.

This species differs from the C. Urii of Fleming, in having but one ring round.the tubercles, and having
the margins of the plates radiatingly ridged instead of granulated ; both of these characters depend so much on the
preservation of the specimen, that their presence or absence may in some measure be considered as accidental, a
very slight disintegration causing the ridges to assume the appearance of tubercles; so that the present species is
very probably the same as that of Fleming, the spines agreeing perfectly. Spines of this species frequently at-
tain to three and a half inches in length; cylindrical, slightly broader in the middle of the muricated part;
diameter at base two lines, length of plate figured seven lines, breadth four lines.

Ecuinocrinus vetustus. Phil. sp.
Cidaris vetusta. Phil. Geol. York.
It is very possible that the spines referred to this species may really belong to the upper part of L. Urit,

being rather smaller but muricated in the same manner; the murication extends nearer to the base in the pre-
sent species.

ADELOCRINUS HIstTRIX. P/il.
Adelocrinus histrix. Phil. Pal. Fos.

A single specimen of this curious fossil has occured ; like Professor Phillips’s specimen, it was a cast in soft
shale; the specimen was about one inch in diameter, and half an inch long, conical, undivided, and covered
with scattered, spine-like tubercles. The specimen was imperfect at each end, and uregularly crushed, so that
Tam unable to add any information to that already known, or even to say whether it truly belong to the Cri-
noidea. It seems very closely allied to the Echinus Humboldtii of Steininger.

Pentremites. Say.

Gen. Ch.—Pelvis of three unequal plates, two pentagonal, and one tetragonal, supporting five large sca-
pule ; ambulacra five, column round; surface of articulation radiated.

PENTREMITES DeERBIENSIS. Sow.

Pentremites Derbiensis. Sov. Zool. Journal. Pentremites Derbiensis. Phil. Geol. York.

Sp. Ch.—Spheroidal; length slightly exceeding the width; pelvis concave; sutures about one-third the
length from the base; surface granulated.

This beautiful little species is easily distinguished from any of those described by Mr. Gilbertson, by its
small size, and nearly basal sutures. Length four lines.

PENTREMITES ELLIPTICUS. Sow.
Pentremites ellipticus. Sow. Zool. Jour.
Sp. Ch.—Longitudinally ovate, length one-third greater than the width; base truncate, concave; sutures
mesial; surface obscurely striated and granulated.

This species, in its lengthened, elliptical form, resembles the P. oblongus, but is at once distinguished by
its mesial sutures.

CARBONIFEROUS FOSSILS OF IRELAND. 175

PENTREMITES FLOREALIS. Say.
Pentremites florealis. Say. Jour. Acad. Nat. Sc. Phil.—Pentremites ovalis, Phil. Pal. Fos. (not of Gold.)

One or two obscure fragments of a Pentremite, have oceurred, which, by their very broad ambulacra, and
general form, seemed identical with Professor Phillips’s species, but certainly not with Goldfuss’s. Captain
Portlock has also observed the P. ovalis in the carboniferous limestone of Sligo, but, from his observations,
it would seem that his specimen too was more allied to that figured by Professor Phillips, than by Professor
Goldfuss. The former seems to me identical with Say’s P. florealis.

Pratycrinus. Miller.

Gen. Ch.—Column elliptical, the joints of which articulate by a transverse ridge ; pelvis of three, unequal

pieces (one piece, according to Mr. Austin) supporting five large scapulz.

PLATYCRINUS conTRACTUS. Phil.
Platycrinus contractus. Phil. Geol. York.

Sp. Ch.—Pelvis acutely conical; scapule nearly twice as long as wide, narrower above than below; sur-

face smooth.
This species is rendered remarkable by the contraction of the upper part of the cup, resulting from the
narrowing of the scapule at their superior end; it is distinguished from the P. similis, M‘Coy, which has

the same character, by its lengthened pelvis.

PLATYCRINUS ELONGATUS. Phil.
Platycrinus elongatus. Phil. Geol. York.

Sp. Ch.—Pelvis elongate, conical; scapule of equal width, straight, one-third longer than wide; articula-
tions small; surface smooth.

This species is rendered remarkable by the great elongation of the scapulz and pelvis; from the P. contrac-
tus, which is almost equally elongate, it is distinguished by having its scapule of equal breadth above and
below; the proboscis is very long.

PLATYCRINUS EXPANSUS. MM ‘Coy. (Pl. XXV. figs. 18, 19).

Sp. Ch.—Pelvis wide, flat, deeply divided; scapulz very large, wider than long; articulations prominent,
large; width of the body at scapular articulations twice the length.

This fine species is distinguished from all of the genus by the great width of the body in proportion to
the length, owing to the scapule being short, and wider above than below; the markings are similar to
those of the P. ellipticus of Phillips, from which, however, its form and proportions will at once distinguish it.
Length ten lines, width one inch seven lines.

PLatycrinus cicas. Phil.
Platycrinus gigas. Phil. Geol. York.

Very large specimens of a smooth Platycrinus, closely resembling the Plat. levis of Miller, and gigas of
Phil., but not shewing the interscapular plates, have occurred.

176 SYNOPSIS OF THE CHARACTERS OF THE

PLATYCRINUS GRANULATUS. Mill.

Platycrinus granulatus. Mill. Hist. Crin.—Platycrinus granulatus. P/il. Geol. York.

Sp. Ch.—Scapular articulation very small; scapular and pelvic plates having several irregular rows of small,
rounded, tubercles.

This beautiful species is very rare; the few specimens which have occurred are easily recognized by the
distinctly tuberculated plates, and minute articulation of the scapula.

PLATYCRINUS INTERSCAPULARIS. Phil.
Platycrinus interscapularis. Phzl. Pal. Fos.

Sp. Ch.—Globose; pelvis saucer-shaped, contracted and produced at the columnar articulation, support-
ing five scapule and one interscapular plate; surface smooth, with few irregularly scattered tubercles.

In this fine species the large interscapulary plate is very remarkable, resembling in this particular the
P. elongatus. Length from scapular articulation to the columnar adherence one inch two lines, diameter one
inch seven lines.

PLATYcRINUS LAcINIATUS. Phil.
Platycrinus laciniatus. Phil. Geol. York.

Sp. Ch.—Pelvis saucer-shaped, constricted and prominent at the columnar articulation; scapule square ;
articulation small; all the plates marked with sharp, very prominent, radiating ridges and tubercles.

This elegant crinoid is distinguished from the P. ellipticus, P. tuberculatus, and other nearly allied spe-
cies, by the constricted, neck-lke prominence of the base of the pelvis.

PLATYcRINUS Lz&vis. Mill.
Platyerinus levis. Méll. Crin.

Sp. Ch.—Plates of the body smooth; scapula of equal width below and above; each supports an arm
having two hands, each of which has two fingers.

This is not the species figured by Professor Phillips as the P. levis of Miller, the figure in the Geol. of
York. represents a species with a small pelvis, and the scapule much narrower below than above, giving a
conical appearance to the body; in the present species, however, the scapule are equally wide above and
below, and the pelvis equal in diameter to any part of the body of the animal. Length of body from scapular
articulations four and a half lines, diameter eight lines.

PLATYCRINUS ORNATUS. MM‘Coy. (Pl. XXV. fig. 1).

Sp. Ch.—Pelvis elongate, conical, attenuated, cylindrical at base; scapule long, narrow, of equal breadth
above and below, each supporting one lengthened, cuneiform arm-joint, having each two hands of great length ;
surface of the pelvis and scapule sculptured with round, curving lines and points; column near the pelvis com-
posed of numerous circular jomts, a thicker and longer one alternating witha thinner and shorter one.

This very curious crinoid is apparently destitute of fingers, the hands being of great length, and tentacu-
lated to their base; the scapular plates are beautifully carved in irregular curved lines; the pelvis has rough-
ened, transverse lines, which follow the curves of the scapular articulations ; the produced cylindrical base of the
pelvis articulates with a cylindrical column, formed of alternately thicker and thinner joints. Length of body
three lines, width two and a half lines.

CARBONIFEROUS FOSSILS OF IRELAND. 177

PLatycrinus punctatus. M‘Coy. (Pl. XXYV. figs. 15-17).

Sp. Ch.—Pelvis very thick, rugged, concave im the middle ; scapule of equal length and breadth, very
thick; all the plates ornamented with equal, close, minute, elevated puncta.

This species is chiefly distinguished from the P. rugosus by its beautifully granulated plates; from the P.
granulatus it differs in the shortness of the scapulz, the largeness of the scapular articulations, and the greater
closeness and minuteness of the puncturing of the plates. The pelvis is small, but thick, rugged, and concave,
except at the edges; the scapulz are very massive, of about equal length and breadth; the articulation from
the cuneiform armjoint very large; interscapulary plates large, pentagonal. Length eleven lines, width nine

lines.

PLatycrinus Rucosus. Mill.
Platycrinites rugosus, Jil. Hist. Crin.—Platycrinus rugosus. Phil. Geol. York.—Platycrinus rugosus.
Portk. Geol. Rep.

Sp. Ch.—Pelvis very flat; scapulz square, very thick, rugged, surface smooth; three fingers to each hand;
scapular articulation very large and low.

The pelvis and scapule are very thick, variously ornamented, according to the degree of muscular con-
traction ; in some cases they are quite smooth, with steeply-bevelled edges, at other times they are rugged, with
variously shaped protuberances, but in all, the surface, when examined with the lens, appears smooth.

PLATYCRINUS sImiLis. M‘Coy. (Pl. XXVI fig. 6).

Sp. Ch.—Pelvis truncated, flat; scapule narrower above than below; length of the scapule about two-
thirds the width of the pelvis.

This species very closely resembles the P. contractus, but is distinguished by its perfectly flat pelvis, and
the shortness of its scapule. Length five lines, width seven lines.

PLATYCRINUS TRIACONTADACTYLUS. M*Coy. (Pl. XXYV. figs. 2-7).

Sp. Ch.—Plates of body smooth; scapule of equal width throughout, each supporting an arm with two
hands and three fingers each.

This species could scarcely be distinguished from the P. levis, were it not for the addition of a third lateral
finger to each hand. It occurs in company with that species at Hook Head in Waterford, in which re-
markable locality, specimens of both those species and many others are found beautifully preserved, with
their column, body, proboscis, hands, tentacula, &c. quite perfect and in situ. The proboscis is very large,
composed of smooth, polygonal plates; it is obtuse at the apex, where the opening appears as a simple sht,
bounded by four quadrangular plates; the fingers are beautifully tentaculated; the column is round near the
pelvis, and formed of joints, alternating a longer and thicker with a shorter and thinner, every seventh one being
alittle larger; at this portion of the column the joints articulate by a radiatingly striated margin only ; lower down,
the joints become elliptical, and the transverse ridge characteristic of the genus appears. Length of body from
the base of arm-joint to base of pelvis three lines and a half; width seven lines; length of proboscis one inch
four lines. Since the plate of this species was printed, Mr. Austin has described (An. Nat. Hist., vol. x1.) a species
under the name of P. trigintidactylus, which may be identical with this; as the description is not very full, and

there is no figure, I am not certain of the fact.
PLATYCRINUS TUBERCULATUS. Mill.
Platycrinites tuberculatus. Mill. Hist. Crin.—Platycrinus tuberculatus. Phil. Geol. York.

Sp. Ch.—Cylindrical, pelvis abruptly truncated, nearly flat, scapule lengthened, equally wide above and

below; marked with irregular rows of tubercles.
YG

178 SYNOPSIS OF THE CHARACTERS OF THE

The specimens which have occurred are very imperfect, and difficultly recognizable; they approach nearer
to the Devonian than to the mountain limestone specimens.

Porerrocrinus GRACILIS. J‘Coy. (Pl. XXV. figs. 11 to 14).

Sp. Ch.—Body, measured from the pelvis to the scapulz, nearly twice as long as wide; smooth, length of
the arm-joint twice its thickness.

This is closely allied to the P. tenuis, Mill., but is much more slender, and the plates of the body pro-
portionably longer; the arm-joint is also much shorter; the column is formed of round, equal, thin joints, with a
broad surface of articulation radiatingly striated; the proboscis is very long, and from the strong, radiating, muscu-
lar ridges, assumes a beautifully stellated appearance. Length of body five lines, width three and a half lines.

Porertocrinus rmpressus. Phil.
Poteriocrinus impressus. Phil. Geol. York.

Sp. Ch.—Conical, smooth, angles of the plates impressed; pelvis very small, supporting five pentagonal
first costals, which are broader than long.

This large species is distinguished by having the angles of the second costals, scapular and interscapular
plates deeply indented; the scapular articulation occupies about two-thirds the width of the plate.

Taxocrinus. Phil.
Isocrinus. Phil. (not Von Meyer),—Bladocrinus. Avst. (not Agas).

Gen. Ch.—Column enlarging towards the pelvis, pelvis of five very small plates; costals five; the joints
are equal and similar, from those to the first cuneiform arm-joint; arms and hands very long.

Taxocrinus MAcRoDAcTyLUS. Phil.
Cyathocrinus macrodactylus. Phil. Geol. York.—Isocrinus macrodactylus. Phil. Pal. Fos.

Sp. Ch.—Pelvis supporting five pentagonal, and five quadrangular, costal plates, bearing five quadrangular
scapulz, each supporting one cuneiform arm-joint, from each of which proceed two hands of five joints dividing
into numerous fingers; surface smooth.

This species occurs of considerable size, but very imperfectly preserved ; I have deviated a little from Pro-
fessor Phillips in my view of the plates of the body, hands, and arms.

TAxocrinus potypactyius. M‘Coy. (Pl. XXVI. fig. 7).

Sp. Ch.—Column of numerous round, unequal joints; about twenty of them at the summit suddenly in-
crease in diameter, but become very thin, and are perfectly equal; those support five pentagonal, pelvic (first
costal ?) joints; these support five heptagonal scapulze(?), each supporting a series of five or six equal, cylindrical
joints, terminating in a cuneiform joint, bearing two hands divided into five or more fingers ; surface smooth.

The complex genus, T'azxocrinus, now contains a considerable number of well-marked species, of which
that before us is not the least curious; the upper joints of the column are suddenly dilated, as we see in
Apiocrinus, forming an enlarged alimentary cavity, and leaving us in doubt as to the true pelvis of the
genus; the supra-columnar joints are five, pentagonal, and support five, large, heptagonal plates, which, perhaps, it
is safer to call seapule than any thing else; from these to the first cuneiform jomt, as we see in the other Tazx-
ocrini, the joints are equal and similar; this joint supports two hands, having each a great number of fingers.
The surface is smooth; diameter of the body at supra-columnar joints six lines. Length from the supra-colum-
nar joint to the tip of the fingers, as far as known, three inches and a half.

Cyatuocrinus. Mill.

Gen. Ch.—Pelvis of five pentagonal plates; supporting five costals; column round or pentagonal; articu-
lating surfaces radiated.

CARBONIFEROUS FOSSILS OF IRELAND. 179

CyatHocrinus conicus. Phil.

Cyathocrinus conicus. Phil. Geol. York.

Sp. Ch.—Cup elongate, conic; pelvis deep, supporting five pentagonal costals, one-third longer than
wide, bearing five scapule; surface granulated.

This narrow, lengthened species is found very rarely. The specimens are too imperfect to give the
measurements.

CYATHOCRINUS ELLIPTICUS. Phil.
Cyathocrinus ellipticus. Phil. Pal. Fos.

The only characters for which the columns to which Professor Phillips has given this name are remarka-
ble, is the very great thickness of the joints; the canal is pentagonal or pentaphylloidal ; surfaces of articulation
finely striated; section usually elliptical, sometimes round.

CYATHOCRINUS GEOMETRICUS. Gold.

Cyathocrinus geometricus. Gold. Pet—Cyathocrinus geometricus. Phil. Pal. Fos.

Only single costal plates of this species have been yet found in Ireland; they are easily recognized by
their beautifully radiated surface.

.

CyatTuocrinus InEquipactytus. M'Coy. (Pl. XXVI. fig. 8).

The above name was provisionally given to a small species of Cyathocrinus, resembling the C. planus, but
with fingers of very unequal length.

CyaTurocrrinus mAcrocueirus. M‘Coy. (Pl. XXV. fig. 8-10).

Sp. Ch.—Column pentagonal; from fourteen to seventeen joints in each hand.

This species is at first sight nearly allied to the C. guinquangularis, Mill., but it is readily distinguished
from it and all others by the enormous length of the hands, those of the C. guinguangularis beg composed
of only two or three joints; the column of the present species is pentagonal, the joints alternately thicker
and thinner, with every fifth one larger; the five plates of the pelvis are rather longer, and more pointed
than those of the C. qguinguangularis, but the costals are shorter, their length and width being about equal; the
arms are formed each of two joints, broader than long, and a cuneiform one, longer than broad, from which two
hands proceed, each having from fourteen to seventeen joints, and a cuneiform one, from which proceed two
fingers, each composed of about twenty-seven joints, and a cuneiform one, from which others again proceed ;
the surfaces of all the plates are smooth.

CyATHOCRINUS MEGASTYLUS. Phil.
Cyathocrinus megastylus. Phil. Pal. Fos.

This name is merely given to some very large stems of Cyathocrini, the characters of which have not been
determined ; the Irish specimens are identical with those figured by Professor Phillips.

CyATHocRINUS oRNATUS. Phil.
Cyathocrinus ornatus. Phil. Geol. York.

A single plate only of this species has occurred; it is easily recognized by two sets of granulated stn
which meet at an acute angle in the centre of the plates.

180 SYNOPSIS OF THE CHARACTERS OF THE

CyaTHocriInus PINNATUS. Goldf. (?)

Cyathocrinus pinnatus. (Gold. Pet. (?)—Cyathocrinus pinnatus. Pil. Pal. Fos.

Only columnar joints of this species have as yet been observed in the Irish carb. series; they are monili-
form, elliptical, thin, alternately larger and smaller; the circumference prominent, with distinct striae of articu-
lation; centre concave, nearly smooth; canal pentagonal.

CyATHOCRINUS PLANUS. Mill.
Cyathocrinus planus. JZill. Hist. Crin.

A few obscure, columnar joints, agreeing in general character with this species, have occurred; they are
nearly equal, circular, smooth; circumference striated; alimentary canal small, round.

CYATHOCRINUS VARIABILIS. Phil.
Cyathocrinus variabilis. P/il. Pal. Fos.

This, as a species, has scarcely any definite character; it is convenient, however, to refer to it all those in-
determinate, small, circular, thin joints of Cyathocrinus, having strongly striated, articulating surfaces, and a
small pentagonal, or pentaphylloidal alimentary canal; no stress, however, should be laid by the geologist on
its occurrence in any particular stratum, for the above reason.

Ruopocrinus (GILBERTSOCRINUS) ABNoRMIS. M‘Coy. (Pl. XXVL fig. 3).

Sp. Ch.—Scapule heptagonal, two pentagonal and three hexagonal intercostals.

This fine species differs from all of the genus in having the scapule heptagonal, and three of the intercostal
plates being hexagonal ; differing thus in some manner from the characters of the genus, as laid down by Professor
Phillips, and being itself a remarkably fine species, I shall give a somewhat detailed description of its structure.
Like most of the genus its general form is hemispherical, with the pelvis concave outwardly ; all the plates are
very convex, so as to give a nodular appearance to the body; the pelvis is small, the suprabasal joints are five,
hexagonal, and rather longer than wide; alternating with, and above these are five very convex, heptagonal,
first costals, on each of which rests a hexagonal second costal; this plate is the most regular and constant in
form of the whole animal; it is longer than wide in the present species; on its upper edge rests a large heptago-
nal scapula; this plate, in all the others of the genus, is small and pentagonal, on the superior lateral edges are
placed two small, hexagonal first arm-joints, having above and between them a small pentagonal, clavicular
plate, and laterally two horse-shoe shaped joints, from which the hands proceed; on the superior edge of three
of the suprabasal joints rests a hexagonal, intercostal plate, having above them several rows of irregular inter-
costals, as in the genus Rhodoerinus. The proboscis is nearly central and elevated. Length of base one inch
three lines, width one inch five lines.

Ruopocrinus verus. JMill.

Rhodocrinus verus. Jz. Hist. Crin.

Columns, possibly referrible to this species, occur rather rarely, they agree in general size, form, striz
of articulation, and pentaphylloidal canal, with the columns referred by Miller to the present animal, but the
identification of columns of Crinoidea, and referring them to their appropriate bodies, is a task of such great
difficulty, that, geologically speaking, it is, perhaps, better either to take no notice of unconnected stems, or,
where they are very characteristic of any particular bed, to give them distinct provisional names for reference.

CARBONIFEROUS FOSSILS OF IRELAND. 181

Actinocrinus. Jill.

Gen. Ch.—Plates of the pelvis, three, supporting six ‘first costal plates, one pentagonal and five hex-
agonal; eleven second costal and intercostal plates bearing five scapulw. Column and alimentary canal
round.

ACTINOCRINUS AMPHORA. Gilbertson.

Melocrinites amphora. old.—Actinocrinus amphora. Porth. Geol. Rep.

Sp. Ch.—Spheroidal, very much depressed; pelvis small, of three pentagonal plates; first costals five hex-
agonal and one pentagonal; length two-thirds the width; second costals very shallow, twice as wide as long;
intercostals hexagonal: arms very large, thick, having each near the base on the upper surface, a very promi-
nent, tubercular plate ; proboscis very large, lateral; with five very prominent, convex plates at its base; surface
of all the plates carved with close irregular flexuous ridges, edges striated.

Actinocrinus constrictus. M‘Coy. (Pl. XXVILI fig. 3).

Sp. Ch.—General figure lengthened, globose ; constricted round the middle of the first costals, below which
the lower portions expand again, forming with the pelvis a broad, tumid base; pelvis broad, hexagonal, of three
plates; first costals, five hexagonal, and one pentagonal, very large, the length of the hexagonal ones equal to
their greatest width, the pentagonal one is somewhat narrower; they all have the upper third flat, or slightly
concave, and the lower two-thirds very convex outwardly; second costals, five, hexagonal, length one-fourth
less than the width, and little more than one-half the length of the first costals; intercostals large, hexagonal,
their length exceeding the width by about one-third, width equal to that of the second costals.

The great size of the first costals, the transverse constriction of the body, and the inflated form of the lower
part of the cup and pelvis, distinguish this readily from the other described species of Actinocrinus. Length of
body one inch seven lines, diameter at the base of the arms one inch four lines. Presented by Mr. Charles B.
Newenham of Cork.

Actinocrinus costus. M‘Coy. (Pl. XXVI. fig. 2).

Sp. Ch.—Scapule hexagonal; first costals longer than wide; costal and intercostal plates very large; a
fourth pentagonal, interscapular plate adheres over a heptagonal intercostal, above the irregular first costal.

The hexagonal scapulz distinguish this fine species from the A. triacontadactylus, Mill., and the A. tes-
sellatus, Phil. ; the disproportionally large costal and intercostal plates distinguish it from all others of the genus,
even when too imperfect to shew the scapula. The general form is pear-shaped, rather narrower than A. tria-
contadactylus ; the pelvis is large; the first costals are of the usual form, very large; the second costals hexa-
gonal, and longer than wide; scapula hexagonal, also longer than wide; the intercostal plates are hexagonal,
large; one of them over the irregular first costal is heptagonal, its superior angle being truncated to support a

fourth interscapulary plate. The muscular markings of the plates are very well shewn in the specimen
figured.
t=)

Actinocrinus Girpertsoni. Ji//. MSS.
Actinocrinus Gilbertsoni. Phil. Geol. York.

Sp. Ch.—Second costals twice as wide as long; all the plates minutely sculptured.
The specimens of this species which have occurred were very imperfect, but the great width of the costals
and the peculiar sculpturing of the plates, will serve to distinguish the species from all, except the 4.
amphora, of which it may be a variety. The specimens I have seen were smaller than that species, and the
sculpturing of the surface finer.
2Z

182 SYNOPSIS OF THE CHARACTERS OF THE

Actinocrinus GLozosus. Phil.
Actinocrinus globosus. Phil. Geol. York.

One or two very obscure casts have been, with doubt, referred to this species. The globular form and
concave base are identical, but the plates of the body are not visible.

Actrnocrinus Lavis. Mill.
Actinocrinites levis. Mill. Hist. Crin.

Several imperfect specimens, referrible to this species, have occurred ; the smoothness of the plates are the
principal distinction from the 4. triacontadactylus.

Actinocrinus Potypactyius. Jil.
Actinocrinites polydactylus. Mil. Crin.—Actinocrinus polydactylus. Phil. Geol. York.

Sp. Ch.—Five arms, each having two hands, terminating in four or five fingers.

This is a smaller species than the A. triacontadactylus, but closely resembles it in many of the details;
the muscular ridges are much more distinct, however, and it is at once distinguished by the greater number of
its fingers; the pectoral plates, when contracted, shew the remarkable character of being palmated, and divided
into several points or branches; abundant in the limestone of Hook Head, some specimens exhibiting the
column upwards of a foot in length (imperfect), the body, arms, hands, fingers, tentacula, proboscis, &c. in
situ.

Actinocrinus Pusittus. M‘Coy. (Pl. XXVLI fig. 4).

Sp. Ch.—Body small, globose, surface of the plates ornamented with minute, curved lines and dots.

This Actinocrinite does not appear ever to attain the size of a large hazel nut; it differs from all of its
genus in the beautifully ornamented plates of the body, which, under the lens, appear sculptured in the most
delicate manner, with raised, twisted lines and isolated points, over which the strong muscular ridges pass. ‘The
pelvis is small, flattened at the base, supporting six large costals; the intercostals are hexagonal, and about
equal to the second costals in size; the scapulz are small, each supporting an arm, having two hands. Length
six lines, width six lines. Occurs in great numbers in one locality.

ACTINOCRINUS TENUISTRIATUS. Phil.

Actinocrinus tenuistriatus. Phil. Pal. Fos.

I have observed several joints of Actinocrinus answering perfectly to Professor Phillips’s figure and de-
scription of this species; they are chiefly remarkable for the fineness of their strie of articulation, and the uni-
form thinness of the joints.

ACTINOCRINUS TESSELLATUS. Phil.
Actinocrinus tessellatus. Phil. Geol. York.

Sp. Ch.—First costals large, hexagonal; three upper sides nearly equal and shortest; second costals hex-

agonal; all the sides nearly equal; scapula heptagonal; surface of the plates nearly smooth, slightly marked at
the edges with short, muscular ridges. P

This species is very rare; the peculiar form of the scapulz distinguish it from the allied species.

ACTINOCRINUS TRIACONTADACTYLUS. Mill.
Actinocrinus triacontadactylus. JZ. Crin.—Actinocrinus triacontadactylus. Phil. Geol. York.

Sp. Ch.—Scapulz hexagonal, supporting five arms, having each two hands provided with three fingers
each.

CARBONIFEROUS FOSSILS OF IRELAND. 183

The column of this abundant species is round, formed near the pelvis of thin joints, alternately a little
longer and thicker, every third or fourth joint larger; nearer the base the joints become of an uniform thick-
ness and size; when young they are contracted at the sutures, so as to be slightly moniliform; the articulating
surface is regularly striated from the centre; round, auxiliary side-arms come off irregularly from the columns;
the plates of the body generally exhibit very distinctly the marks of muscular contraction, in the form of strong,
variable, radiating ridges. The fingers are formed, as usual, of two series of joints. Length of body from the
scapulz one inch, width one inch three lines.

Puruirsocrinus. MM‘ Coy.

Gen. Ch.—Pelvis saucer-shaped, composed of one pentagonal and three hexagonal plates; supporting one
pentagonal and six hexagonal first costal plates; five of which, having their superior margins truncated, support
five scapule ; the pentagonal costal and one of the hexagonal costals, having their upper margin angularly
pointed, support no scapulz; between each of the scapulz is interposed a single hexagonal, interscapulary plate,
but over the pentagonal costal, and over the hexagonal one with the pointed summit, two of them adhere
laterally together.

This genus differs from all others of the tribe, in the great number of the costal plates ; it approaches most
nearly to the genus Caryocrinites of Say, from which it differs in the form of the plates of the pelvis; that
genus has but six costals, this has seven; in Caryocrinites, four of the costals are pentagonal, and two hexa-
gonal; in the present genus there are six hexagonal, and but one pentagonal; in Phillipsocrinus, there are
seven interscapulary plates, and but five arms, while in Caryocrinus there are but two interscapulary plates, and
there are six arms. Only one species is as yet known. I have dedicated the genus to Professor Phillips.

PHILLIPSOCRINUS CARYOCRINOWES. MM‘Coy. (Pl. XXVL fig. 5).

As but one species is known, the generic characters above given will identify it; it will be only necessary
to add, that the plates exhibit the marks of strong, muscular contraction, as in Actinocrinus, between which

the surface is minutely and irregularly, but beautifully sculptured. Length from scapule eight lines, width one
inch.

Atocrinus*. MM‘Coy.

Gen. Ch.—Column composed of round joints, alternately thicker and thinner; pelvis and entire visceral
cavity composed of one undivided piece, from which proceed five arms of one cuneiform joint, each supporting
two hands, composed of one cylindrical, and one cuneiform joimt, each; one hand of each arm having three
fingers and the other but two, the fingers composed of a single row of joints.

The genus Atocrinus has been formed for the reception of a little Crinoid, having the remarkable cha-
racter of an undivided cup, the plates of the pelvis, scapule, &c. being all anchylosed (in Symbathoerinus, Phil.,
it is the pelvic plates only which are anchylosed). The fingers are thick, tapering but slightly, and composed
of but one series of joints, the hands are equal, one having two fingers and the other three.

Atocrinus Mintert. M‘Coy. (Pl. XXV. fig. 20).

- Having had an opportunity of examining only one specimen of the genus, the above character will, at the
same time, indicate the only known species. Three of the joints nearest the pelvis are rather smaller than the
rest, and uniform in size; the cup is hemispherical, a little dilated at the insertion of the cuneiform arm joint,
surface smooth. Length from the pelvis to the tip of the finger seven lines.

* 4, privative,—rzuve, seco, from its undivided cup.

184 SYNOPSIS OF THE CHARACTERS OF THE

ACRITA.

The Aerita form the lowest division of the animal kingdom; they have no appreciable nervous sys-
tem, no brain, nor nervous filaments, consequently, no organs of sense, and, consequently also, no muscular
system; they have no true circulation, in the highest of them only, has a movement been detected in their
nutrient fluids; and, finally, their digestive system is composed of a few rude cavities in the general paren-
chyma of the body, but without distinct walls or abdominal cavity. Of those the Zoophyta are the most inte-
resting to the geologist.

ZLOOPHY TA.

The Zoophyta, or Polyps, exhibit great diversity of structure; the most perfect, or Ciliobrachiate polyps,
are very complex, and differ very much from the rest; they form a separate group, under the name of Bryozoa ;
they inhabit tubular cells, and have the tentacula which surround the mouth covered with vibratile cilia, the
currents produced by the action of which are sufficiently powerful to hurry the minute animals on which they
live into their mouth; their muscles are fibrous; the intestinal mass floats in a distinct cavity, and is composed
of a mouth, large esophagus, gizzard, stomach, biliary glands, intestine, and anus; it is, m fact, as complex as
that of a bird, yet some of the most ancient fossil corals we know, apparently belong to this group, as this Plus-
tre and Eschare, as well as some others, resembling the ordinary tubular polyps. Of the unciliate polyps, the
most highly organized are the tubular polyps, compound animals, whose common body is encased ina branched,
tubular, horny sheath; the extremities of the branches are open, forming cells, each of which contains a hydra-
like portion of the animal, having a mouth, surrounded by ten nodular tentacula, by which food is provided for
the entire community. The detinee, or Sea Anemonies, although they could not be found in the fossil state, are
interesting to the geologist, from their resemblance to the animal of Turbinolia, Cyathophyllum, and probably
Amplexus. They are short, cylindrical animals, having their base formed into a sucker-like dise, by which they
are attached; the opposite extremity is fringed with numerous, short, perforated tentacula, having the mouth in
the centre, which communicates directly with a simple, closed, bag-like stomach; the space between the sto-
mach and the external muscular walls of the animal, contains a great number of vertical, fibrous lamellz ; it is
those lamella, strengthened by calcareous matter, which we see in the fossil T'urbinolia, and Cyathophyllum ; m
Amplexus, in which the calcareous lamell are merely rudimentary, they were probably continued in a fibrous or
membranous state towards the centre, as in the other species; the spaces between those lamelle contain
the ovaries. The Twbiporide inhabit tubular, calcareous corals; they live in society, but are not organically
connected with each other; the little animal inhabiting each tube is provided with eight simple, flattened
tentacula, each having a few rows of papille on the edge; alternating with these are eight slender ovaries,
which hang within the tube; in the centre is a simple stomach, as in Actinia; the small portion near
the mouth of the tube, which is inhabited by the animal, is lined by a membrane, which secretes at the
bottom of the cell a transverse, calcareous diaphragm, such as we see in Turbinolia, and Cyathophyllum;
those partitions, of course, increase in number with the age of the animal. Next to those we have the
Corallide, which differ entirely from the last, the solid portion of the animal forming a variously branched
horny, or caleareous stem, covered by a thick coating of living, soft, irritable matter, in which are seated
at intervals the most beautiful and brilliantly coloured polypi, each furnished with eight fimbriated ten-
tacula; those polypi provide nourishment for the entire community; they are capable of retraction within
the cells of the living cortex, but have no immediate connexion with the central axis, in which there are
no cells. Then come the Madreporade, in which there is still an external living crust, and scattered polypi;
but those latter are lodged in cells in the stony, central portion of the animal. The Aleyonide scarcely

CARBONIFEROUS FOSSILS OF IRELAND. 185

differ, except in the want of the calcareous support, the central portion being as soft as the external. The
Hydre resemble the separate or single polyps of the last group, but are single, unattached, and capable of
locomotion; they are of no direct interest to the geologist. Finally, we have the Fungie, which, although the
solid portion resembles that of the higher lamelliferous corals, is much less highly organized, being, in fact, a
mere gelatinous investment to the lamelle of the skeleton, which it thinly coats, without tentacula, mouth, sto-
mach, ovaries, or any other organs.

AMPLEXUS. Sow.
Gen. Ch.—Cylindrical, divided into chambers by numerous, transverse septa, which embrace each other
with thin, reflexed, crenulated margins ; outer surface striated longitudinally; inner surface ribbed with short,
equal lamella, none of which reach the centre.

AMPLEXUS NoDULOSUS. Phil.
Amplexus nodulosus. Phil. Pal. Fos.

Sp. Ch.—Irregular, elongate, tortuous, unequally swollen or nodular ; septa as in A. Sowerbii; surface
concentrically wrinkled.

The irregular, nodular character of the tube, and strong, concentric wrinkles, are the principal characters
which distinguish this species from the 4. Sowerbii.

Ampcexus Sowersu. Phil.
Amplexus coralloides. Sow. Min. Con.—Amplexus Sowerbii. Pil. Geol. York.

Sp. Ch.—Cylindrical, regular, divided by plain, equidistant, transverse septa, with embracing, crenated
margins; surface nearly smooth; longitudinally striated.

This remarkable coral, when young, is attached by a very slender, conical base, but as it increases in size it
becomes cylindrical; the conical portion is less than one inch long, and is about half an inch in diameier, and
from this upwards it is cylindrical. Now as we often find specimens upwards of a foot long, and an inch and
three-quarters in diameter, perfectly cylindrical, it becomes difficult to imagine how so long and heavy a body
could be supported on so slender a stem; so that hence the interesting question arises, was the adult Amplexus
free? My friend, Dr. Scouler, is known to have paid much attention to this interesting animal, and we may ere
long expect an able account of the species from his pen.

AmPLEXus TorTuosus. Phil.
Amplexus tortuosus. Phil. Pal. Fos.

Sp. Ch.—Cylindrical, tortuous; septa simple ; marginal plates about twenty-four; surface longitudinally
striated and concentrically wrinkled.

The septa not being plaited at the edges forms the most important distinction of this species from the
A. Sowerbii, it is likewise much smaller, more tortuous, and more equally cylindrical, than that species. Dia-
meter of tube about seven lines.

TurBINoLopsis. Lamour.

Gen. Ch.—Inversely conical, terminating in a deeply concave, stellular disc; lamella smooth, alternately
longer and shorter, notched on the edges; no transverse septa.
I am not aware of any character of generic importance by which to separate the present genus from the
old Turbinolie or rather Cyathophyllum, if we except the alleged want of transverse septa in Turbinolopsis,
3A

186 SYNOPSIS OF THE CHARACTERS OF THE

but, owing to the state of preservation in which those fossils are usually found, it is almost impossible to
decide whether they were present or not; some of the Irish specimens appear to have been attached.

TURBINOLOPSIS BINA. Lons. ?
Turbinolopsis bina. ons. Sil. Syst. ?—Petraia bina. Lonsd. Geol. Trans.—Turbinolopsis bina. Phil. Pal. Fos.

Sp. Ch.—Conical ; cup deep; lamella about thirty, strongly toothed on the edges, between each pair a very
fine slightly elevated ridge, marked with regular, impressed puncta.

This little species is common in the carb. slate, as well as in the shales of 8. Devon, but they appear to
me to differ considerably from the Silurian coral of the same name. Length of cast about four lines, width five
lines.

TURBINOLOPSIS CELTICA. Lamour.
Turbinolopsis celtica. Phil. Pal. Foss.

Sp. Ch.—Elongate, conic; cup deep; lamelle about forty; strongly toothed on the edges.

This species is common; it is rather more gradually tapering than the 7. bina, and is constantly distin-
guished by the greater number of the lamelle; these are usually forty in the Irish specimens, but forty-eight
according to Phillips, in those from Torquay, while from twenty-four to thirty is the usual number in the
T. bina. Length of cast seven lines, width six lines.

TURBINOLOPSIS PAUCIRADIALIS. Phil.
Turbinolopsis pauciradialis. P/il. Pal. Fos.
Sp. Ch.—Very rapidly expanding, short; lamelle very thin, distant, finely serrated, about twenty in
number; between each pair an obtusely rounded ridge.

The small number of the lamelle distinguishes this at once from the others of the genus. Length of cast
eight lines, width eleven lines.

TURBINOLOPSIS PLURIRADIALIS. Phil.
Turbinolopsis pluriradialis. Phil. Pal. Fos.
Sp. Ch.—Obtuse; aperture expanded; cup deep; lamellx about eighty; between each pair a row of im-
pressed puncta.

The very great number of the lamelle, and consequent narrowness of the intermediate spaces, distin-
guishes this species from the others of its genus. Length one inch two lines, width eleven lines.

TURBINOLIA.

Gen. Ch.—Turbinate, free, base attenuated; star single; internally composed of vertical lamellz and dis-
tant, transverse septa.

TURBINOLIA EXPANSA. M‘Coy. (Pl. XXVIII fig. 7).

Sp. Ch.—Inversely conical, breadth double the height; lamelle about 120, twisted towards the centre.

A curious and rare species, easily known from the T. fungites, by the extreme expansion of the disc, which,
measured across the star, is usually double the length; the ordinary length of the 7’. fungites is about four
inches, measuring, at that length, about one inch across the star; the present species very rarely attains a length
of one inch and a-half, measuring at that length two inches and three-quarters across the star. I have seen

CARBONIFEROUS FOSSILS OF IRELAND. 187

young specimens three-quarters of an inch long; they do not expand so rapidly as the adult, but are, at that

age, more widely different from the 7°. fungites.

TURBINOLIA FUNGITES. Vem.

Turbinolia fungites. Vem. Brit. Anim.—Turbinolia fungites. Phil. Geol. York.

Sp. Ch.—Obliquely conical, curved; transversely wrinkled, star concave, lamell about 112.

This species is liable to great variation in its characters, when young and preserved in shale, exposed to
the action of the atmosphere, it is impossible to distinguish them from Twrbinolopsis, when old, the number
of the lamell increases, and transverse septa appear; when very old, it becomes cylindrical, and then ap-
proaches very closely to Siphonophyllia; the characters of the species are best known when about two inches
long, the star is then about one inch in diameter.

SIPHONOPHYLLIA CyLinDRICA. Scowler. MSS. (Pl. XX VII. fig. 5).

The beautiful coral to which my friend, Dr. Scouler, has given the above name, resembles, in some, degree
a gigantic specimen of the T'urbinolia fungites, it is, however cylindrical for the length of ten or eighteen
inches ; the middle of the coral exhibits a number of transverse plates, about a line or two distant from each
other, and bearing crowded, erect lamine. Down the side of each runs a distinct syphon, from which the genus
derives its name; the interval between the plates and the exterior is occupied by a cellular substance similar to
that of the Cystiphyllum of Lonsdale.

ASTRA.

Gen. Ch.—Polypidom, composed of parallel, aggregated, polygonal prisms, terminating each in a stel-
lular disc.

ASTRHA ARANEA. M‘Coy. (Pl. XXVIL fig. 6).

Sp. Ch.—Stars large, polygonal; very irregular in size and the number of angles; slightly convex, with a
large, oval, central hollow or cup, having in the middle a flat, elliptical umbo; interstices very thin, smooth,
straight; lamellz about fifty, very delicate, equal (or nearly so), all seeming to reach the centre.

This beautiful species forms large masses in the limestone of certain localities; the stars are much larger,
and less regular in shape, than those of the A. erenularis, or A. hexagona, most nearly resembling the A. heli-
anthoides in those respects; from this latter species it is distinguished by the less number of its lamella, the
oval form of its cup, and the large, compressed umbo.

ASTRHA CRENULARIS. Phil. sp.
Cyathophyllum crenulare. Phil. Geol. York.

Sp. Ch.—Discoid; stars unequal, polygonal, their margins prominent, sharp, denticulated; central umbo
twisted; conical cup deep; lamellz about forty-six, alternately longer and shorter.

ASTREA IRREGULARIS. Portk.
Astrea irregularis. Portk. Geol. Rep.
Sp. Ch.—Discoid, stars small; very irregular in size and shape; chiefly pentagonal, their margins thin,
prominent, sometimes undulated; lamell about thirty-five, nearly equal in length.
This species resembles the 4. pentagona, but is distinguished by its more numerous lamelle, nearly all
of which reach the centre, while they are alternately longer and shorter in that species.

188 SYNOPSIS OF THE CHARACTERS OF THE

ASTREA PENTAGONA. Blain.
Astrea pentagona. Lonsd. Geol. Trans.—Astreea pentagona. Phil. Pal. Fos.

This species differs from the last, principally in the fewer lamellx, and the greater distance between
them ; and in the margin of the stars being bent or indented in a zigzag manner, by the extremities of the
lamelle on each side.

Lirnostrotion. Park.
Columnaria. Goldfuss.

Gen. Ch.—Coral, composed of adhering, prismatic, parallel tubes; each having a single, terminal star.

LITHOSTROTION sTRIATUM. Park.
Lithostrotion striatum. Park. Organ. Rem,.—Cyathophyllum basaltiforme. Phil. Geol. York.

Sp. Ch.—Tubes prismatic, irregular, polygonal, longitudinally or transversely striated; marginal lamelle,
about forty, commencing within a crenulated vertical dissepiment.

This beautiful fossil occurs occasionally in abundance; it varies considerably in the number and shape of
its sides, these are usually plane, but sometimes specimens occur in which they are convex; the striation
varies from longitudinal to transverse, and the diameter of the tubes, from three to six lines; but so irregu-
larly are those characters distributed, sometimes in the same specimen, that it is obvious they all belong to one
species.

Lirnopenpron. Schwerg.

Gen. Ch.—Coral, cylindrical, branched, adhering by the base, each tube with a single, terminal, stellular
disc.

LITHODENDRON AFFINE. Mart. sp.
E. Madreporites affinis. Martin, Pet. Derb.—Lithodendron longiconicum. Phil. Geol. York.
Sp. Ch.—Tubes thick, loosely branched, exteriorly smooth; lamelle sixty-four, alternately longer and
shorter.
This large species occurs usually in thick beds or masses, often of great size; it is easily known from the

other species by its smooth surface, Diameter of the tubes about five lines.

LITHODENDRON CASPITOSUM. Mart. sp.
E. Madreporites cespitosa. Mart. Pet. Derb.—Lithodendron fasciculatum. Phil. Geol. York.
Sp. Ch.—Tube flexuous, irregular, slightly nodulous; longitudinally striated; lamelle about twenty-five
within, fifty without.
This species forms bundles or masses, often of extraordinary extent, in certain localities; the tubes are
irregularly wrinkled concentrically, and marked with obtuse, smooth, longitudinal striz, Diameter of tubes
four lines.

LITHODENDRON coARCTATUM. Portk.
Lithodendron coarctatum. Portk. Geol. Rep.

I have only seen one bad specimen of this species; the tubes are smooth, crowded, little more than a
line in diameter. I am not aware of the differences which are supposed to exist between this species and the
L. sexdecimale of Phillips, Geol. York ; the specimen I have seen is not good enough to determine the
question.

CARBONIFEROUS FOSSILS OF IRELAND. 189

LITHODENDRON PAUCIRADIALIS. MM‘Coy. (Pl. XX VIL fig. 7).

Sp. Ch.—External tube smooth, one-sixth of an inch in diameter, slightly flexuous, parallel, often coa-
lescing, branches few; lamellae, ten or eleven within, twenty or twenty-two without; an internal tube uniting
the lamellz, within which a small crenulation, or radiating set of lamella appear, one between each of the
large ones.

This differs from all the known species of Lithodendron in the small number of the principal lamellae, or
those which reach the centre; externally it differs from the L. fascieulatum in its smooth surface; from the ZL.
affine (longiconicum) in the smaller diameter of the tube, and from all the species in its peculiar mode of branch-
ing and crowded, nearly parallel mode of growth.

LITHODENDRON SEXDECIMALE. Phil.
Lithodendron sexdecimale. Phil. Geol. York.

Sp. Ch.—Tube small, slightly flexuous, loosely branched; surface generally smooth; mesial lamella six-
teen, with curved, vertical dissepiments.

This pretty species is the smallest of its genus found in the Ivish limestone, the tubes being rarely thicker
than a crow-quill; the surface is sometimes finely striated, but generally smooth; it forms masses of considera-
ble size, but is amuch rarer and more local species than any of the foregoing. Diameter of tubes one line.

LITHODENDRON SocIALE. Phil.
E. Madreporites duplicata. Mart. Pet. Derb.?—Lithodendron sociale. Phil. Geol. York.

Sp. Ch.—Tubes thick, close, frequently adhering laterally to each other; surface with obtuse, waving
longitudinal striz, and concentric wrinkles; axis ovate; radiating lamelle, about sixty-four, alternately longer
and shorter.

This is the largest species of the genus, and from its curious habit of the tubes occasionally adhering late-
rally to each other, so as to give them an angular contour, it evinces an approximation to the genus Lithos-
trotion ; the longitudinal strie are thick and obtuse; diameters of tubes seven or eight lines.

Syrmncopora. Goldfuss.
Harmodytes. Fisch.

Gen. Ch.—Coral, formed of vertical, flexuous, cylindrical tubes, anastomosing by transverse tubul..

SyrRincopora BiruRcATA. Lonsd.
Syringopora bifurcata. Zonsd. Sil. Syst.

Sp. Ch.—Dichotomous, branches short, oceasionally anastomosing, connected by small, transverse tubuli ;
surface smooth; diameter of tubes one line.
This species is distinguished by its regular dichotomizing.

SYRINGOPORA CATENATA. Mart. SP.

Tubiporites catenata. Mart. Pet. Derb.—Harmodytes parallela. Fisch. Oyct. Mos.—Syringopora reticulata. Grold.
Pet.—Harmodytes radians. Bronn. Leth. Geog.

Sp. Ch.—Tubes small, slightly flexuous; connecting tubuli placed at regular distances.
This delicate species is easily distinguished from the S. geniculata by its straighter, thinner, and more re-
gular tubes, it is more nearly allied to the S. ramulosa, but from that it is distinguished by its more regularly

placed, transverse tubuli, and much more slender tubes. Diameter of tubes half a line.
3B

190 SYNOPSIS OF THE CHARACTERS OF THE

SYRINGOPORA GENICULATA. Phil.
Syringopora geniculata. Phil. Geol. York.

Sp. Ch.—Tubes round, branching, irregularly flexuous or geniculated, wrinkled across, united by very
numerous, short, transverse tubuli.

This curious species is remarkable for the frequent short bendings of the tubes; the connecting tubuli are
numerous, and at the origin of each the tube is angularly bent; this occurring so frequently, and at such short
intervals, gives an irregularity to the tubes which is very characteristic. This species forms masses, frequently
of great extent. The tubes are about one line in diameter.

SYRINGOPORA LAXA. Phil.
Syringopora laxa. Phil. Geol. York.
Sp. Ch.—Tubes thick, straight, occasionally branched, adhering without connecting tubuli.
This singular species has not, I believe, been yet figured; it forms bundles of considerable size, but I have

not seen the transverse tubuli in any specimens which have come under my examination; the tubes are nearly
straight. Diameter of tubes one line and a half.

SYRINGOPORA RAMULOSA. Gold.
Syringopora ramulosa. Gold. Pet.—Syringopora ramulosa. Phil. Geol. York.
Sp. Ch.—Tubes slightly flexuous, nearly parallel; tubuli alternating at very unequal distances.
In this species the tubes are nearly smooth, rather distant, and connected by irregular, transverse tubuli.
Diameter of the tubes one line.
AULOPORA.

Gen. Ch.—Parasitic ; cells tubular, cylindrical ; united at the extremities, irrecularly branching.

AULOPORA CAMPANULATA. M‘Coy. (PI. X XVI fig. 15).
Sp. Ch.—Incrusting ; tubes short, conical, expanding to a very wide, bell-shaped mouth.
The singularly large, bell-shaped mouth of the tubes distinguishes this handsome species from any other

with which I am acquainted; it is usually found parasitic on the Orthis crenistria. Diameter of tubes at
mouth one line.

Auvtopora Gicas. M‘Coy. (Pl. XXVIL fig. 14).

Sp. Ch.—Repent; tubes cylindrical, forming a very open, irregular net-work ; ostiole distant, circular,
erect; diameter of the tubes one line.

This coral greatly resembles the Silurian A. serpens, but is much larger and more loosely branched; the
specimen figured is attached to a cylindrical Twrbinolia.

MANoN criprosum. Gold. ?
Manon cribrosum. Gold. Pet. ?—Manon cribrosum. Phil. Pal. Fos. ?
One or two small and very obscure fragments of a coral have occurred allied to this species, but much

smaller in its details than any of the published figures; if it varies as much in size as the Porites pyriformis,
they may be of the same species. It is, however, a doubtful reference.

CARBONIFEROUS FOSSILS OF IRELAND. 191

AstTREoporA ANTIQUA. M*Coy. (Pl. XXVLI. fig. 9).

Sp. Ch.—Discoid, convex; surface with large, circular cells, in quincunx, about one-third their diameter
apart; sides of the cells radiatingly striated ; intervening flat spaces, with minute, irregular, curving ridges.

This fossil closely resembles the Hydnopora cyclostoma of Phillips; the genus Hydnopora (or Monticu-
laria) has the stars raised above the surface, a character which our fossil certainly does not possess, but which
may, perhaps, be better placed in the genus Astreopora, in which the cells are cylindrical, with striated sides.
If Professor Phillips’s coral and mine were specifically the same, it would be necessary to change his generic
name as above; and as all the Astreopore have circular cells, the specific name would be also objectionable,
and might be changed as I have proposed. It is probable, however, that the two species are distinct. I have
seen several specimens of the Insh species, and they are all free, while Professor Phillips's coral is parasitic on
shells; the proportions also, or number of cells in a given space, is different in the two. Diameter of masses
about one inch, diameter of cells one line.

DicruopHyituia. De Blainville.

Gen. Ch.—Incrusting, fixed; cells large, polygonal, irregular; whole surface strongly reticulated.

DicTuoPHYLLIA ANTIQUA. MM‘Coy. (Pl. XXVI. fig. 10).

Sp. Ch.—Cells nearly equal, polygonal; their raised margins granulated.

This species may be distinguished from the D. reticulata of the chalk by its greater size, more regular
cells, and the margin of the cells being irregularly granulated instead of being striated, as in that species.
Diameter of stars about five lines.

PLEURODICTYUM PROBLEMATICUM. Gold.?
Pleurodictyum problematicum. Gold. Pet. ? Pleurodictyum problematicum. Phil. Pal. Fos. ?

Sp. Ch.—Oval, depressed; superior surface divided into numerous, large, irregular, pentagonal, or acutely
rhomboidal cells, by thin septa, perforated by numerous, small foramina.

The specimens which have occurred in Ireland are extremely imperfect, and cannot be referred with accu-
racy to the Devonian species, not shewing more than one or two of the perforated septa; the cells are remark-
able for their acutely rhomboidal section.

Favosites. Lam.
Calamopora. Gold.
Gen. Ch.—Maassive, composed of vertical, diverging, prismatic tubes, connected by transverse tubuli or
foramina.
FAvosiTEs CAPILLARIs. Phil.
Favosites capillaris. Phil. Geol. York.

Sp. Ch.—Spheroidal, composed of very fine, prismatic tubes; the transverse septa are arranged at equal
distances and height in all the tubes.

This beautiful species usually forms spherical masses, the size of an orange, the tubes are literally hair-like,
being scarcely visible in a section parallel to their length; on the surface, however, they form a delicate network
of minute, polygonal cells. Diameter of specimens usually about three inches, six tubes measure one line
across their openings.

192 SYNOPSIS OF THE CHARACTERS OF THE

Favosites Friprosa. Gold. sp.
Calamopora fibrosa. Gold. Var. a.—Favosites fibrosa. Lonsd. Sil. Syst.—Favosites fibrosa, Phil. Pal. Fos.

Sp. Ch.—Branching ; formed of very fine, lengthened, polygonal tubes, not flexuous, connected by tubuli
on the angles.

This species is very common; it is variously branched, the termination of the branches being obtusely
rounded; the tubes are much longer and straighter than in the F’. spongites or FP’. septosus, they are also finer.

Favosites Gotuianpica. Lam.

Favosites Gothlandica. Zam. Anim. Sans. Vert.—Calamopora Gothlandica. Gold. Petref_—Favosites Gothlandica. Lonsd.
Sil. Syst.

Sp. Ch.—Polymorphous, composed of pentagonal or hexagonal tubes, the sides of which have one or two
rows of minute, connecting foramina, transverse septa at irregular distances.

The size of the tubes, number of angles, and number of pores vary considerably in this species, as also
the form of the general mass; the usual diameter of the tubes is about one line.

Favosites (?) mMecastoma. Phil. sp.

Calamopora megastoma. Phil. Geol. York.

Sp. Ch.—Incrusting, discoid; cells very large, polygonal or rounded, with strong, radiating, internal striz ;
numerous connecting foramina at their edges.

This species forms discoid, convex masses, often of considerable size; the cells are large, regular, and with
rather thick walls; the lateral perforations generally very distinct. Cells usually five lines in diameter.

FavosiTes (?) PARASITICA. Phil. sp.
Calamopora parasitica. Phil. Geol. York.

Sp. Ch.—Incrusting; cells very irregular in shape and size; their sides irregularly perforated.

This species differs chiefly from the C. megastoma, Phil., in the small size and irregular shape of the cells;
the lateral perforations are few, very minute and far apart; the tubes composing the cells are also longer in pro-
portion, and the cells deeper than in that species. Cells usually about one line and a half in diameter.

FAVOSITES POLYMORPHA. Gold. sp.
Calamopora polymorpha. Gold. Pet.—Favosites polymorpha—Lonsd. Sil. Syst.—Favosites polymorpha. Pl. Pal. Fos.

Sp. Ch.—Branched, composed of numerous large tubes externally polygonal, internally cylindrical ; con-
nected by alternating tubuli; tubes about one-third of a line in diameter.

This is rather a rare coral, but casts of it occasionally occur, shewing the peculiar branched form, and
the impressions of the large openings of the tubes. Diameter of the branches usually from half to two-thirds
of an inch.

FAvosItes seprosus. Hem.

Favosites septosus. Vem. Brit. Anim.

Sp. Ch.—Hemispherical, forming a thick, flattened crust, composed of rather coarse, slightly flexuous, poly-
gonal tubes, in which the transverse septa are irregularly placed.

This species approaches very nearly to the F. spongites of the Silurian rocks, but it is, perhaps, safer to
leave them distinct in the present state of our information on the species. The greater size of the tubes and

CARBONIFEROUS FOSSILS OF IRELAND. 193

irregularity of the transverse septa, distinguish it from the F. capillaris. Thickness of the masses about one
inch, there are three tubes in the space of one line.

FAvosITEs SPONGITES. Gold.
Calamopora spongites Gold. Petref. Germ.

The specimens referred to this species are closely allied to the /. spongites, but have the tubes slightly
flexuous; they are probably, however, identical.

Favosires (MIcHELINIA) TENUISEPTA. Phil.
Calamopora tenuisepta. Phil. Geol. York.—Michelinia tenuisepta. Moninck, Fos. Bel.
Sp. Ch.—Conical, proliferous; external surface of the tubes convex, wrinkled across; cells very unequal,
rounded within, numerous, small, connecting foramina in the sides.
This remarkable coral occurs usually in company with the nearly allied species C. megastoma and para-

sitica. Length usually about two and a half inches, width one and a half inches, diameter of the cells vary-
ing from one to three lines.

Favosires Tumipa. Phil. sp.
Calamopora tumida. Phzl. Geol. York.

Sp. Ch.—Subramose, irregular, formed of concentric layers of square tubes, the mouths of which are con-
tracted to a smaller orifice at the surface, and whose angles bear numerous connecting foramina.

This species is exceedingly irregular in form, and it appears probable that different species, and even
genera, may be confounded under the one name.

CAUNOPORA PLACENTA. Phil.

Coscinopora placenta. Lonsd. Geol. Trans.—Caunopora placenta. Phil. Pal. Fos.

Sp. Ch.—Form irregularly tumid; composed of concentric lamin, pierced by two sets of tubes, one
set numerous, very fine, and flexuous, the others larger, straight, cylindrical.

I have used Professor Phillips’ name to distinguish the Irish coral as well as the Devonian, although I
conceive it to be totally distinct as a species from the Coscinopora placenta of Goldfuss; as Professor Phillips
has already shewn, it cannot enter into the genus Coscinopora of that author.

STROMATOPORA CONCENTRICA. Lonsd.
Stromatopora concentrica. Lonsd. Sil. Syst.—Stromatopora concentrica. Phil. Pal. Fos.
Sp. Ch.—Polymorphous, composed of numerous, thin, approximate, concentric lamine, perforated by fine,
straight tubes; horizontal section finely reticulated.
This is rather a doubtful species in the carboniferous series, the amorphous masses it usually forms having

little the appearance of organized bodies; owing to the compactness of the limestone, it is often difficult to see
any of the characters of the coral, which has, therefore, been frequently passed over.

STROMATOPORA POLYMORPHA. Gold.

Stromatopora polymorpha. Gold. Pet.—Stromatopora polymorpha. Lonsd. Geol. Trans.—Stromatopora polymorpha.
Phil. Pal. Fos.
Sp. Ch.—Polymorphous ; concentric lamine traversed by fine, vertical tubes; horizontal section irregularly
radiated and reticulated round many unequal centres.

3C

194 SYNOPSIS OF THE CHARACTERS OF THE

This irregular coral is not uncommon in some districts, but the characters are seldom well seen in a lime-
stone specimen, unless accidentally weathered.

SrrRoMATOPORA suBTILIS. M‘Coy. (Pl. XXVII. fig. 9).

Sp. Ch.—Heteromorphous, composed of thin, concentric layers, pierced by fine, perpendicular tubes; struc-
ture scarcely visible to the naked eye.

In structure it resembles the 8. concentrica, but is much finer and more delicate in all its parts. From
the appearance of some of the specimens, a doubt might be entertained of its being organic.

Crerropora. Gold.

Gen. Ch.—Polypidom, tuberose, composed of numerous, thin, concentric layers; pores round, unequally
placed.

This genus was intended by Goldfuss to include several fossil forms, now referred to Alveolites, Chrysaora,
&c.; the above definition is of the genus as now restricted.

Crriopora pistans. M‘Coy. (Pl. XXVIL fig. 13).
Sp. Ch.—Subcylindrical, verrucose ; pores small, equal, conspicuous.
A coral, which closely resembles the C. verrucosa of the Silurian rocks. The specimen figured is in

the collection of the Geological Society of Dublin; it is more lengthened than usual. Length of specimen
one inch five lines; diameter nine lines.

VerticittoporaA. De Fran.

Gen. Ch.—Polypidom, branched, cylindrical, composed of aggregated, polygonal tubes, divided by trans-
verse septa; axes hollow or filled.

VERTICILLOPORA ABNORMIS. Lonsd. (?)
Verticillopora abnormis. ons. Sil. Syst. (?)
Specimens agreeing with the above in general character occur, but too imperfect to furnish a detailed de-

scription ; they differ from the Y. dubia, M‘Coy, in the greater size and regularity of the ostiole, the reference
is, however, made with much doubt.

VERTICILLOPORA DuBIA. M‘Coy. (Pl. XXVII. fig. 12).

Sp. Ch.—Dichotomous, cylindrical, branches obtuse ; axis hollow in adults, filled in young branches; com-
posed of numerous, very unequal, polygonal tubes; ostiole forming an irregular network on the surface.

Tn this species the tubes are very irregular in size and shape, they are parallel to the axis for the greater part
of their length, and then diverge towards the surface, where they form a very irregular net work; the hollow
space of the axis 1s very large in proportion to the solid external part, except in the young branches, which
are completely filled with the tubes. I have not seen the septa.

FLUSTRA.

Gen. Ch.—Foliaceous, or incrusting, flexible; cells contiguous, arranged in regular series, forming a reticu-
lated surface.

Fiustra PALMATA. M‘Coy. (Pl. X XVI. fig. 14).

Sp. Ch.—Foliaceous, divided into numerous, flattened, palmated branches; cells on both sides, with very
numerous, minute, polygonal openings; their outer covering and opening unknown,

CARBONIFEROUS FOSSILS OF IRELAND. 195

This species closely resembles in form our recent Flustra foliacea, the substance of the fossil species is,
however, thicker than in any of the recent foliaceous FJustre with which I am acquainted. If this be a true
Flustra it belongs to that division of the genus having the cells on both sides; it is, however, very possibly a
Favosite; the whole surface is beautifully reticulated with minute cells. Length of some branches two inches,
thickness of the lobe about one line.

BerenicEa. Lamourous.

Gen. Ch.—Parasitic ; cells united in a spot-like crust, radiating from a centre, adhering throughout, not cir-
cumscribed ; mouth at the distal extremity of each cell; substance submembranaceous.

BrrENICEA MEGASTOMA. M‘Coy. (Pl. XXVI. fig. 13).

Sp. Ch.—Mouth of the cells very large, prominent, semicircular, inclining from the centre.

The general form of this little coral is that of a small, nearly circular, flat scale; the openings of the cells
are unusually large, and having a raised edge only to the superior half of the margin, their form appears
nearly semicircular.

ORBICULITES ANTIQUUS. M<Coy. (Pl. XXVI. fig. 16).

Sp. Ch.—Circular, flat; openings of the cells numerous, oval, nearly in quincunx order, their own diame-
ter apart. Diameter of dise one-third of a line.

This very remarkable little coral occurs in abundance in the shales of some localities, but from its small size
it is very likely to be overlooked; the intercellular spaces are flat and smooth.

MILLEPORA.

Gen. Ch.—Polymorphous; pores very minute, perpendicular to the surface; cells without lamellz.

MILLeporaA GRACILIS. Phil.
Millepora gracilis. Phil. Pal. Fos.
Sp. Ch.—Slender, cylindrical; cells rhomboidal, in quincunx ; interstices granular.
This very common species is known from the M. rhombifera by its coarsely granular interstices; the M. in-

terposa, Phil., is distinguished by its sgle row of impressed pores between the cells. Length usually one inch,
diameter three-fourths of a line.

MILLEPORA INTERPOROSA. Phil.
Millepora interporosa. Phil. Geol. York.
Sp. Ch.—Slender, cylindrical, dichtomous; cells oval, interstices broad, smooth, with a row of minute, im-
pressed pores.
This is the rarest species of the genus, and also the most beautiful; the rows of pores in the interstices are
variable, both in number and position, in the different specimens; the cells are smaller and more oval than in the
M. rhombifera or M. gracilis. Length usually from one to two inches, diameter three-fourths of a line.

MILLEPoRA (PustuLopora) ocunaTa. Phil.
Millepora oculata. Phil. Geol. York.
Sp. Ch.—Compressed, dichotomous, branches at right angles to the stem; four rows of very large, promi-
nent pores.
The great size of the cells, with their entire oval, prominent margins, distinguish this species from all except
the M. spicularis, Phil., while in its rectangular manner of branching it differs from all the other Paleozoic
species.

196 SYNOPSIS OF THE CHARACTERS OF THE

MILLEPORA RHOMBIFERA. Phil.
Millepora rhombifera. Phil. Geol. York.

Sp. Ch.—Cylindrical ; surface with equal, rhomboidal cells, arranged in quincunx.
This pretty species is not uncommon; it is easily known by its round section, and rather large, acute, rhom-
boidal cells. Length usually from one to two inches, diameter three-fourths of a line.

Mitiepora siuiuis. Phil.
Millepora similis. Phil. Pal. Fos.

Sp. Ch—Stem oval, elongate, flexuous, dichotomous ; surface with numerous rows of close, rhomboidal
pores in quincunx.

This species is very closely allied to the M. rhombifera, Phil.; from which, however, it is easily distin-
guished by its much superior size, and its flexuous, depressed, dichotomous stem.

Mitterora (PustuLopora) spicuLanris. Phil.
Millepora Spicularis. Phil. Geol. York.
Sp. Ch_—Stem slender, round, branched; branches short, simple, terminating in fine points; surface with
rows of prominent, oval, unequal cells.
This elegant little species is distinguished from its congeners by its numerous short, spicular branches. Its
stem is much smaller than in any of the other mountain limestone species.

Tracos. Schweig.

Gen. Ch.—Halycondroid; skeleton simple, spicular; form capitate, attached by a root or bundle of fibres
expanding to a disc, with distant, unequal ostiolz,

TRAGOS SEMICIRCULARE. JM/‘Coy. (Pl. XXVIL fig. 8).

Sp. Ch.—Pedicle semicylindrical, surmounted by a semicircular, flattened head; ostiola on the upper sur-
face large, scattered, with achannel from each to the convex margin; truncated margin furnished, with several
short processes.

This fossil is so totally different in character from any other zoophyte which I know, that I am still uncer-
tain to what exact group it should be referred; it appears, however, to belong to the family Spongiade, but not
to any of those divisions having interlaced fibres; the genus T'ragos is, in my mind, most nearly allied to it,
although the pedicle being at the margin instead of in the centre, and the numerous root-like processes to the
truncated margin, point out differences in habit worthy of generic distinction. Greatest diameter one inch, least
diameter six lines. Only two specimens have occurred.

Gorconta. Linn.

Gen. Ch.—Axis corneous, with osseous spicule ; polypiferous basis cretaceous ; polypi developed ; cells ses-
sile, with simple or spinose margins.

GorconiA assmminis. Lonsd.
Gorgonia assimilis. Lonsd. Sil. Syst.

Some specimens referrible to this obscure species have occurred ; the general size, form, and occasional
anastomozing of the branches are the only characters visible.

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CARBONIFEROUS FOSSILS OF IRELAND. 197

GorGontA Lonsparerana. M‘Coy. (Pl. XX VII. fig. 1).
Sp. Ch.—Stem irregularly rounded, curved, or straight, rarely dichotomizing ; pores irregular, projecting,
papillate.
This very curious coral is of rare occurrence; the cells for the polypi resemble warts, as in many of the
living species, but their margin is indistinct; the external and internal portions of the branches are distinctly
visible in some specimens.

Gorconta zic-zac. M'Coy. (Pl. XXVIII fig. 2).

Sp. Ch.—Flabelliform, very much branched, reticulated ; fenestrules irregular in size and shape, most fre-
quently nearly square, with rounded angles; interstices thick, rounded, irrecularly flexuous, forming a zig-zag
series of salient and re-entering angles; dissepiments short, about half the diameter of the interstices; axis
coarsely striated ; cortex finely granulated.

The separation of cortex and axis is clearly discernible in some portions of the specimen.

Janta. Lamouroux.
The few Corallines which I have noticed, as of this genus, should, probably, be removed to the vegetable
kingdom, but not having any other plants to describe, I have left them, for the present, in their old place

among the corals.

JANIA ANTIQUA. M'Coy. (Pl. XXVLI. fig. 12).

Sp. Ch.—Trichotomously branched ; branches slightly curved; of equal diameter throughout their entire
length; cylindrical, external crust thin.

This curious coralline, in its trichotomous mode of branching, resembles the Coralline, but m general
habit, and in the branches being equally thick at both ends, it is more nearly related to the Amphiroe, but has
not the disjoined branches of that genus. The cavity left by the shrinking of the internal, fleshy axis is very
large, leaving but a thin, external, calcareous crust. Length of branches about half an inch, diameter halfa

line.

JANIA BACILLARIA. M‘Coy. (Pl. XXVI fig. 11).

Sp. Ch.—Dichotomous; branches very slender, cylindrical; suddenly dilated at the summit to a short,
conical figure, more than double the diameter of the stem.

The lengthened, slender stems of the branches, with their suddenly dilated tip, resemble in form the an-
tique tobacco pipes so commonly found in our fields; it is one of the most remarkable corallines of the carb.
series. Length of branches half an inch, diameter of stems one-third of a line, dilated summits one line.

JANIA crASSA. M‘Coy. (Pl. X XVII fig. 4).

Sp. Ch.—Irregularly dichotomous; branches thick, conical, short; slender at their origin, expanding ra-
pidly; surface smooth.

This is by much the largest species of this group I have seen; it is common in the shales of several lo-
ealities; it most nearly resembles the J. bacillaria, M‘Coy, from which it differs in the great thickness and
conical form of the branches. Length of specimens usually from one to two inches; length of branches about
three lines, diameter of branches at base usually about one line, at extremity one line and a half.

Vincutaria. De Fran.

I have used this name here for those simply formed species, without lateral branches, and having more
than two rows of pores. I have not separated those specimens which have the pores all round, from those having

3D

198 SYNOPSIS OF THE CHARACTERS OF THE

them on one side only, as it seemed impossible to separate generically such species as the V. parallela (Flustra,
Phil.) from such as the V. raricosta, M‘Coy.

Vincutaria picHotoma. M‘Coy. (Pl. XXVII. fig. 15).

Sp. Ch.—Dichotomous; obverse rounded, with about six equal, parallel, slender, longitudinal ridges, in
the concave furrows, between which are five rows of oval, prominent cells, the marginal furrow on each side
free of cells; reverse flat, with numerous, semicircular, scale-hke wrinkles, and about six longitudinal striz.

When seen with the flat side up this curious zoophite resembles Ellis and Solander’s Galaxaura margi-
nata of the Bahama Islands more than any other coral; the obverse, however, resembles that of the V. parallela,
Phil. Common. Width of branches one line, length from one to three inches (imperfect).

VINCULARIA MEGASTOMA. M‘Coy. (Pl. XXVII. fig. 10).

Sp. Ch.—Elongate, slender ; section elliptical, obverse with about three rows of large, subrhomboidal cells
arranged alternately, the rows slightly inosculating; the sharp spaces intervening between the cells form longitu-
dinal, waving ridges, and marked with waving, longitudinal strie ; reverse without cells striated longitudinally.

This pretty little coral is about the size of the Millepora gracilis, Phil. from which it differs in the large
size and small number of the cells, and by having the cells on one side only; from the V. raricosta, M‘Coy,
it is distinguished by wanting the straight parallel ridges, and by the great size, rhomboidal form, and small
number of the cells, and the flexuous and striated character of the intercellular spaces; from the Millepora
rhombifera, Phil., it also differs in the large size and small number of the cells. Length of specimens usually
about three or four lines, diameter about one-fourth of a line.

VINCULARIA PARALLELA. Phil. sp.
Flustra parallela. Phil. Geol. York.
Sp. Ch.—Linear, thin, flattened, membranous; about six or seven longitudinal ribs on each side; between
each pair is a row of large, oval pores, with raised margins; sides smooth, without pores.
This coral presents most essential differences from the recent genus Flustra. It varies somewhat in size,
thickness, and the number of the longitudinal furrows. Length from one to two inches, width half a line.

Vincutaria RaRIcosTA. M‘Coy. (Pl. XXVIL fig. 11).

Sp. Ch.—Elongate ; sides parallel; section elliptical; most convex on the porous side; poriferous face con-
vex, marked with fine, sharp, parallel keels, enclosing between them four rows of pores; pores round, or slightly
oval, with prominent margins, placed twice their diameter apart, but irrecularly with regard to each other; re-
verse flattened, faintly marked with exceedingly fine, numerous, waving striz; sides indented each by a pro-
minent row of pores.

This coral is distinguished from the Flustra paraliela, Phil., by having pores in the lateral furrows, and
the sides strongly indented by prominent rows of pores, and from the V’. multangularis, Portk., by the larger
size, and much less number of the longitudinal rows of pores, and by having them on one side only. Length of
specimens usually about one inch, width rather more than half a hne.

Gravuconome. Lonsd. (not of Gold.)

Gen. Ch.—Stem elongate, oval, laterally branched; obverse bearing longitudinal rows of pores; reverse
striated.

I have assigned this genus to Mr. Lonsdale, rather than to Professor Goldfuss, as the former author was
the first to point out the true characters of those elegant corals.

CARBONIFEROUS FOSSILS OF IRELAND. 199

GLAUCONOME BIPINNATA. Phil.
Glauconome bipinnata. Phil. Pal. Fos.
Sp. Ch.—Bipinnate, secondary branches very short; obverse with two rows of approximate, oval pores;
reverse with strong granulated strie.
This species is nearly allied to the G. pluma, but differs in its bipinnate mode of branching, and in having
the secondary branches much shorter, and as if truncated; the pores also differ.

GLauconomeE Graciuis. M‘Coy. (Pl. XXVIII. fig. 5).

Sp. Ch.—Very slender, elongate, simply pinnate; lateral branches opposite, short, slender; obverse of the
stem strongly carmated ; with, on each side, a row of very large, circular, prominent pores, which strongly indent
the margin; one is placed at the origin of each lateral branch, and one in the intermediate space, about half
their own diameter apart; lateral branches without keel; pores large, round, very prominent, and indenting the
margin, arranged alternately in inosculating lines; reverse, convex, with about four strong, granulated, longitu-
dinal ridges.

This elegant species is very common in some localities. It is distinguished from the G. pluma, Phil., G.
disticha, Goldf., and G. bipinnata, Phil., by the large, circular, prominent pores of the stem; it 1s much
smaller, or rather more slender than those species, in which also the margin is entire. The specimens are usu-
ally about one inch in length; stem about one-fifth of a line in diameter.

GLAUCONOME GRANDIS. M‘Coy. (Pl. XXVIIL fig. 3).

Sp. Ch.—Stem less than twice the thickness of the lateral branches; lateral branches rather more than the
width of the midrib apart, obscure; lateral branches carinate, and bearing two alternating rows of very small,
round, prominent pores, which indent the margin slightly; the stem is obscurely carinate, and has usually two
rows of small, round, prominent pores, which do not alternate, or reach the margin; one at the origin of each
lateral branch, and three between one branch and the next.

The small size, and great number of the pores distinguish this from every other species of Glauconome I
know. It is a very large species. Length of imperfect specimen one inch nine lines; length of lateral branches
two lines; diameter of midrib about half a line. Collected by Mr. Charles B. Newenham of Cork, who kindly
presented the specimen figured.

GLAUCONOME PLUMA. Phil. sp.
Retepora pluma. Phil. Geol. York.

Sp. Ch.—Branches alternating at very regular distances; on the midrib two rows of very large, ovate
pores, subalternate with prominent margins; pores on the branches small, round, regularly alternating; reverse
longitudinally striated.

This little species has the pores on the midrib so large as to occupy the entire of the poriferous surface;
the branches are numerous, close, and regularly alternate. Length about one and a half inches, diameter of
midrib one-third of a line.

‘GLAUCONOME PuLCHERRIMA. M‘Coy. (PI. XXVIII fig. 4).

Sp. Ch.—Stem bipinnately branched, main stem and principal branches strongly keeled, branchlets both of
the main stem and branches regularly attenuate, without keel; pores large, with prominent margins, one row
on each side of the principal stem and branches, and one very minute row on the keel; pores on the branchlets
as large as those of the branches, but approximate, almost inosculating, there being no keel to separate the two
rows; reverse finely striated longitudinally.

200 SYNOPSIS OF THE CHARACTERS OF THE

This beautiful species is not likely to be confounded with any other of the genus; the specimens are often
of considerable size, two inches being the usual length.

‘Prytopora. Sc. MSS.

Gen. Ch.—Flabelliform, or infundibuliform, attached by roots, from which a strong midrib arises, giving
origin on each side to thin, equidistant interstices, connected by regular dissepiments; external face of the
interstices carinate, and bearing two rows of pores.

PryLoporA FLUSTRIFORMIS. Phil. sp.
Retepora flustriformis. Phil. Geol. York., and Phil. Pal. Fos.

Sp. Ch.—Midrib square, coarsely striated; interstices thick, equidistant; fenestrules small, oval, equal;
dissepiments as thick as the interstices, equidistant; pores small, round, five or six to the length of a fenestrule.
A very beautiful, feather-like coral.

“Prytopora prumMaA. Sc. MSS. (Pl. XXVIIL fig. 6).

Sp. Ch.—Midrib very thick; general form feather-shaped; mterstices with a regularly poriferous keel;
pores small, round, four to the length of an interstice.

The coral to which Dr. Scouler has given this name appears to differ from the P. flustriformis, in its nar-
row, feather-like outline, the length being three times the width; the midrib is also larger and more distinctly
poriferous. I have not, however, examined good specimens.

Frenestetta. Miller.

Gen. Ch.—Cup-shaped, conical, reticulated, formed of thin, carinated, radiating ribs (interstices), con-
nected by transverse, nonporiferous bars (dissepiments), two rows of prominent pores on the external, carinated
face of each interstice.

This excellent genus is easily distinguished from Retepora by its nonporiferous, transverse bars, and its
poriferous face being external instead of internal, as in that genus. From my genus Polypora it is distin-
guished by its poriferous face being carinated, and having normally but two rows of pores (in most Fenes-
telle I have observed a very irregular row of small pores on the central keel); from Hemitrypa it is known
by the apparent want of the external (imperforate ?) sheath, which at present seems peculiar to that genus*.

FENESTELLA ANTIQUA. ons.
Fenestella antiqua. ons. Geol. Trans. (not Sil. Syst.)—Fenestella antiqua. Phil. Pal. Fos.

Sp. Ch.—Interstices thin, equidistant, irregularly branching; dissepiments very thin, equidistant; fenes-
trules nearly twice as long as wide, slightly rounded; pores large, prominent, five to the length of a fenestrule,
the two rows apparently inosculating.

This species differs from the true F. antigua of the Silurian rocks, as Mr. Lonsdale and Professor Phillips
have already noticed, in the contiguity of the two lines of pores.

FENESTELLA CARINATA. M'Coy. (Pl. XXVIII. fig. 12).

Sp. Ch.—Interstices externally, close together, irregularly bifurcate ; dissepiments and interstices flattened,
of equal breadth, and on the same level; fenestrules circular; poriferous face of interstices angular, with a strong,
longitudinal keel in the middle; dissepiments very thin, small, rounded; fenestrules elongate, oval. Two irre-
gular rows of pores with projecting margins, and one irregular row on the central keel.

*T have recently observed this sheath in some of the true Fenestelle; Hemitrypa is, therefore, possibly only the -
perfect state of Fenestella.

CARBONIFEROUS FOSSILS OF IRELAND. 201

This coral to the naked eye has the appearance of a perfectly flat surface, with regular, round dots re-
sembling pin holes.

‘ FENnESTELLA crassa. (M‘Coy. (PI. XXIX. fig. 1).

Sp. Ch.—Spreading ; interstices thick, strongly keeled, irregularly branched ; dissepiments very thin, dis-
tant; fenestrules large, very elongate, irrecular; pores rather small, few, twice their diameter apart, without
raised margins; a few irregular, small pores on the central keel; reverse striated.

This species is allied to the Fenestella laxa, Phil., but is rather more regular in its habit; it likewise differs
in the dissepiments being much thinner, the interstices being strongly carinated, and the greater distance of the
pores, which, so far from being tubular, have not even the raised margin found in nearly all of the genus. The
reverse of the #. /axa is also granulated with great regularity, while in the present species it is regularly striated.
The figure is taken from a portion of a specimen three inches long, and four and a half inches wide; the inter-
stices are half a line thick.

» FENESTELLA EJUNCIDA. M‘Coy. (PI. XXVIII fig. 11).

Sp. Ch.—F labelliform, interstices nearly straight, equidistant, very thin; dissepiments nearly as thick as
the interstices, placed at regular distances; fenestrules large, nearly equal in size and shape; oblong, shghtly
longer than wide, about three times as wide as the interstices; pores small, prominent, placed alternately, one

at the origin of each dissepiment, and four in the intervening space; seven or eight interstices in the space
of three lines.

FENESTELLA FLABELLATA. Phil... sp.
Retepora flabellata. Phil. Geol. York.

Sp. Ch.—Slightly spreading, irregularly branched; interstices very thin, distinctly carinated ; dissepiments
searcely half as thick as the interstices, equidistant; fenestrules equal, rectangular, twice as long as wide; width
equal to that of an interstice; pores very prominent, deeply indenting the margin; three to the length of a
fenestrule ; reverse sharply striated longitudinally.

A pretty little species, easily distinguished from the F. tenuifila, by its smaller size, and the deep indenta-

tions produced by the pores on the margin of the fenestrules, the striz of the obverse are also sharper and
more direct.

FENESTELLA ForMosA. MM‘Coy. (Pl. XXIX. fig. 2).

Sp. Ch.—Flat, leaf-like ; interstices thin, irregularly branching; fenestrules large, irregular in size and
shape; dissepiments very thin; pores of the sides of the interstices large, numerous, their thickened edges
indenting the margin, four or five to the length of a fenestrule; at each bifureation, and at each setting off of
a dissepiment, is one pore, nearly twice the size of the others; in the middle of each dissepiment is placed one
oval pore, and on the strong keel of the interstices is a very recular row of small pores, all having raised
margins.

Once seen with the lens this remarkable coral can never be forgotten; to the naked eye it has much of
the habit of the common Fenestella undulata, Phil., but the extraordinary disposition of the pores separates
them at once; it is very constant in its characters, several specimens from different localities presenting pre-
cisely the same structure; it forms the most beautiful object for the microscope that can be conceived. Length
about one inch, width half an inch; there are about three interstices in one line.

FENESTELLA FRUTEX. M‘Coy. (Pl. XXVIII fig. 10).

Sp. Ch.—Flabelliform; rising from a distinct root or trunk, and suddenly expanding to a nearly circular
- network; fenestrules broad, usually quadrangular, but rather irregular in size and shape; interstices thick, fre-
quently branching, slightly flexuous, irregular; dissepiments thin, at regular distances; pores very prominent,

3 E

202 SYNOPSIS OF THE CHARACTERS OF THE

their own diameter apart, placed much on the sides, so as to indent the margins of the fenestrules deeply ;
they are placed alternately, usually two to each fenestrule, and one at the origin of each dissepiment; about
five interstices in the space of one line; reverse with coarse, waving striz.

This beautiful little species in its mode of growth resembles a little shrub, or tree, having a short, thick
trunk, and suddenly expanding to a nearly circular head; it is not uncommon; the specimens being about
one-fourth of an inch long, and very constant in form.

FENESTELLA HEMISPHERICA. M‘Coy. (Pl. X XIX. fig. 4).

Sp. Ch.—Hemispherical, ewp-shaped; interstices and dissepiments exceedingly minute; interstices thin,
sharply carinated, reverse longitudinally striated; dissepiments one-fourth the thickness of the interstices;
fenestrules rectangular, wider than the interstices, and somewhat longer than wide; pores small, twice their
diameter apart, with raised margins which do not indent the edge; about three pores to the length of a fenes-
trule.

This beautiful coral forms a hemispherical cup, the root or base being slightly excentric, a few longitudinal
folds or undulations disturb the regularity of the form; the substance of the coral itself is so exceedingly deli-
cate, that it is only after a close examination with good lenses that it can be at all made out; the fenestrules
are usually longer, and the pores consequently farther apart than in the drawing. Length one inch two lines,
diameter one inch six lines; there are about seven interstices in one line.

FENEsTELLA LAXA. Phil.
Retepora laxa. Phil. Geol. York.—Fenestella laxa. Phil. Pal. Fos.

Sp. Ch.—Interstices thick, rounded, very irregularly branched, dissepiments round, nearly equal to the
interstices in thickness; fenestrules very large and extremely irregular in size and shape; there is no keel on
the poriferous face of the imterstice; pores numerous, small, approximate, with raised margin, reverse regularly
granulated in quincunx.

This species is distinguished by its great size, the looseness and irregularity of its branching, and its regu-
larly granulated reverse. The interstices are half a line in thickness.

FENESTELLA MEMBRANACEA. Phil. sp.

Retepora membranacea. Phil. Geol. York.

Sp. Ch.—Elongate, conical; interstices straight, equidistant, with a sharp, central keel; dissepiments
nearly equal in thickness to the interstices; fenestrules elongate, rather wider than the interstices, nearly three
times as long as wide; pores small, about three in the length of a fenestrule ; nonporiferous face granulated.

This abundant species is remarkable for its very elongate, conical shape; it is fixed at the base by long, solid,
nonporiferous roots, of considerable thickness; the lengthened form of the regular fenestrule, and the granula-
tion of the nonporiferous face, are the most important specific characters. This species often grows to a length
of nine or ten inches; five interstices occupy about one line. I have recently seen a specimen exhibiting traces
of the external sheath of Hemitrypa.

FENESTELLA Morrisu. M‘Coy. (Pl. XXVIII fig. 14).

Sp. Ch.— Expanded, conical, cup-shaped ; interstices thick, round, regularly branching; dissepiments very
thin, at nearly equal distances; pores large, nearly their own diameter apart, with very prominent margins; about
six to the lencth of a fenestrule ; fenestrules slightly irregular, usually quadrangular, one-third longer than wide,
reverse nearly smooth.

CARBONIFEROUS FOSSILS OF IRELAND. 203

This species is somewhat cup-shaped; very much expanded, with the root excentric; usually one-fifth of
the diameter from one of the sides; the dissepiments are unusually delicate, and have frequently disappeared,
while the other parts of the coral are in good preservation. I have named this species in honour of my friend,
Mr. J. Morris, the author ofthe elaborate and highly useful Catalogue of British Fossils.

FENESTELLA MULTIPORATA. M‘Coy. (Pl. XXVIIL fig. 9.)

Sp. Ch.—Foliaceous; interstices thin; sharply keeled, irregularly branched; dissepiments thin, distant,
fenestrules large, very elongate, irregular; pores very numerous, small, margins tumid, seven or eight to the
length of a fenestrule; reverse regularly striated.

The great number of pores between each dissepiment is the most remarkable peculiarity of this species. It
grows frequently to a length of two or three inches; there are about three interstices in one line.

FENESTELLA NopuLosA. Phil. sp.
Retepora nodulosa, Phil. Geol. York.

Sp. Ch.—Flat, expanded, fan-shaped ; interstices thick; dissepiments equidistant, regular, half as thick as
the interstices; fenestrules quadrate, rounded at the extremities, constricted in the middle, length and breadth
nearly equal; pores large, with very prominent margins, more than their own diameter apart, one at the origin
of each dissepiment, and one in the middle, deeply indenting the margin.

This interesting coral is very closely allied to the F. plebeia, M‘Coy, but is easily distinguished by the

single, very prominent, mesial pores, constricting the sides of each fenestrule, giving them somewhat of an
hour-glass form.

‘ FeNESTELLA ocuLATA. M‘Coy. (Pl. XXVIIL fig. 15).

Sp. Ch.—Interstices very broad, flattened, rarely branched, obscurely keeled; dissepiments less than one-
fourth the thickness of the interstices, regularly placed; fenestrules half the width of the interstices, rectangular,
three times as long as wide; pores placed close to the margin, very large, with a thickened margin, which
deeply indents the sides of the fenestrule, three between each dissepiment; reverse smooth. '

This species is remarkable for the great proportional size of the interstices, and the size and prominence
of the pores; the keel on the interstice is nearly obsolete. Occurs usually in fragments, about one inch in
length: there are about two interstices in one line.

FENESTELLA PLEBEIA. M‘Coy. (PI. X XIX. fig. 3).

Sp. Ch.—Flat, expanded, fan-shaped; interstices thick; fenestrules equal, rectangular, from two to three
times as long as wide; width equal to that of the interstices; dissepiments thin, regular; pores four or five to the
length of a fenestrule ; reverse minutely granulated, and very coarsely sulcated longitudinally.

This is a very abundant species.

FENESTELLA POLYPORATA. Phil. sp.
Retepora polyporata. Phil. Geol. York.

Sp. Ch.—Interstices thick, rounded (not carinated ?), irregularly branched ; dissepiments short, thin, placed
at irregular distances; fenestrules large, very irregular in size and shape; pores very small, impressed, from five
to seven to the length of a fenestrule.

This is a very interesting species, as exhibiting one of those aberrant types of form so important to the sys-

204 SYNOPSIS OF THE CHARACTERS OF THE

tematic zoologist; in its thick, uncarinated interstices, and small impressed pores, it makes an approach to the
genus Polypora, M‘Coy, but they are disposed in two rows only, as in the true Fenestelle.

FENESTELLA QUADRADECIMALIS. M‘Coy. (Pl. XXVIII. fig. 13).

Sp. Ch.—Interstices slightly flexuous, thin, irregularly branching; dissepiments thin, distant; fenestrules
very large, irregular in shape, pores very numerous, prominent, about fourteen to the length of a fenestrule ;
reverse finely striated longitudinally.

This species is remarkable for the immense number of pores between one dissepiment and the next, four-
teen being the usual number; the interstices are very thin, but often dilated at the point of branching; the
fenestrules are of great size but very irregular.

- FENESTELLA TENUIFILA. Phil. sp.
Retepora tenuifila. Phil. Geol. York.

Sp. Ch.—Slightly spreading, irregularly branched, interstices very thin, sharply carinated; fenestrules
nearly square, little longer than wide; width equal to twice the thickness of the interstices; dissepiments half
the thickness of the interstices; pores small, their prominent margins indenting the edge about three to the
length of each fenestrule; reverse with waving, longitudinal striz.

This delicate species is remarkable for the excessive thinness of the dissepiments and interstices, except at
the branchings; the fenestrules are nearly square. There are about five interstices in one line.

FENESTELLA UNDULATA. Phil. sp.
Retepora undulata. Phil. Geol. York.

Sp. Ch.—Interstices and dissepiments very thin; fenestrules large, irregular; pores very large; rather dis-
tant, prominent, indenting the margin, about four to the length of a fenestrule; reverse with undulating, longi-
tudinal striz.

This is a loosely branched but very delicate species, the substance of the coral itself being very slender; the
fenestrules are four or five times the width of the interstices; the pores are only subalternate, and so large as to
give a nodular aspect to the interstices. It grows to upwards of two inches in length; there are about two
interstices in the space of one line.

- FenesTELLA varicosa. M‘Coy. (Pl. XXVIII fig. 8).

Sp. Ch.—Interstices unequal, those from which the branches originate being twice the thickness of the
others; dissepiments thin, irregularly placed; fenestrules shghtly irregular, usually quadrangular; pores mode-
rate, unequal, from four to six to the length of a fenestrule; reverse nearly smooth.

This is one of the most extraordinary species with which I am acquainted, from the character of some
of the interstices suddenly increasing to double their normal thickness, and, after giving out numerous thin
branches, chiefly from one side, dwindling again to the original size, and continuing their course. Whenever,
from the origin of the interstices, it becomes necessary for one of those thin branches to dichotomize, it suddenly
doubles its thickness for a certain length, and, as long as it remains thick, it gives off branches as before; all the
interstices are slightly flexuous; the reverse is very convex, and nearly smooth.

-Hemirryea. Phil.

Gen. Ch.—Polypidom, a stony, cup-shaped net-work, keeled, and poriferous, as in Fenestella, covered
with an external (imperforate ?) sheath.

CARBONIFEROUS FOSSILS OF IRELAND. 205

Hemirrypa Hipernica. Se. sp. (Pl. XXIX. fig. 7).
Fenestella Hibernica. Scouler, MSS.

Sp. Ch.—Polymorphous, irregularly conic; internal net-work having the interstices equidistant, straight
fenestrules equal, oblong, rounded; length rather less than twice the width ; dissepiments thinner than the in-
terstices ; internal non-poriferous face rounded, smooth ; external poriferous face angular; pores small, oblong,
(not prominent ?) about three to the length of a fenestrule; external sheath nearly smooth, marked externally
with faint, equidistant striaz, which coincide with the interstices of the internal net-work, and enclosing between
them two alternating rows of large, rounded, or obscurely hexagonal depressions, coinciding with the openings
of the internal net-work.

This curious coral throws much light on the structure of Professor Phillips’s genus Hemitrypa. The in-
ternal net-work bears much resemblance to the #. membranacea, Phil., but from the difficulty of procuring
well-preserved specimens of this latter, it is difficult to determine the question satisfactorily ; in the present coral
however, the fenestrules seem to be generally shorter in proportion to their length; the dissepiments thinner ;
and the obverse either smooth or (in some specimens from shale), with large, irregular, distant, spiniform tu-
bercles, but never granulated in the minute and regular manner of the F. membranacea.

‘ Hemitrypa ocunata. Phil.
Hemitrypa oculata. Phil. Pal. Fos.

I have referred with hesitation to this species, some fragments, belonging evidently to the genus
Hemitrypa, but distinct from the H. Hibernica; they are much smaller in their details than that species,
and approach more nearly to Professor Phillips’s figures of the H. oculata; the openings in the external sheath
are small and round, as they are figured and described in that species, differing remarkably from the large,
hexagonal ones in the H. Hibernica; the interstices also of the internal network are oval, as in the Devonian
species, while in the former one they are square; the specimens, however, are not good enough to define the
species properly.

IcutuyroraAcuis. MM‘ Coy.
YY

Gen.Ch.—Coral plumose, composed of a straight, central stem or midrib, having on each side a row of short,
simple branches or pinnz, all in the same plane; obverse both of the midrib and lateral branches rounded, with-
out keel, and each bearing several rows of small, prominent, oval pores, arranged in quincunx; reverse rounded,
smooth, or finely striated.

The present genus stands nearly in the same relations to Glauconome, Lons., as Polypora, M‘Coy, does to
Fenestella, Miller. Fenestella and Glauconome are carinate on the obverse, and bear two rows of large, pro-
minent pores, while Polypora and Icthyorachis are rounded on the obverse, and bear several rows of small
pores arranged in quincunx. It is probable that this is the fossil alluded to by Mr. Miller, when he quotes ver-
tebre of fishes in the Cork limestone, no bony fishes occurring in those formations, and the coral very
strongly resembling the spine of a small fish; I have named the genus from this resemblance iy@¥¢ a fish, and

paxic, a back-bone.

Icutuyoracuis Newennami. M‘Coy. (Pl. XXIX. fig. 8).

Sp. Ch.—Stem and lateral branches with five rows of oval, prominent pores, closely arranged in quincunx ;
reverse flattened, slightly convex, divided by a deep groove along the middle; obsoletely striated longitudi-
nally; lateral branches half the thickness of the midrib, space between them equal to the diameter of the
midrib.

one

206 SYNOPSIS OF THE CHARACTERS OF THE

I have named this fine coral after Mr. Charles B. Newenham of Cork, a gentleman who has most assiduously
collected the fossils of that neighbourhood, and whose Collection has furnished the only examples of the species
which have been seen. Length of specimens, imperfect at both ends, one inch eleven lines; diameter of midrib,
one line. Length of lateral branches, as far as known, about five lines; they are about one line apart.

Potyrora. M‘Coy.

Gen. Ch.— Expanding, interstices round, branching, having on one side from three to five rows of pores,
the margin of which is never raised, interstices connected by thin, transverse, nonporiferous dissepiments.

This genus is very abundant in the carboniferous limestone, and as it appears to form a verynatural group
distinct both from Retepora and Fenestella, I have, after much hesitation, ventured to characterize it. From
Retepora it is easily distinguished by its nonporiferous dissepiments, and general habit; from Fenestella it is
well distinguished by the numerous rows of pores, and the absence of a keel on the interstices; the species of

the present genus do not appear to assume an infundibuliform or cup-shaped figure, but are usually flat and
fan-shaped.

Potypora penpDRoIDES. M‘Coy. (Pl. X XTX. fig. 9).

Sp. Ch.—F lat, fan-shaped, interstices thick, recularly branched, divaricating; dissepiments very thin,
frequently oblique, and placed at nearly equal distances; fenestrules large, rhomboidal, poriferous face, with
five rows of small impressed pores arranged in quincunx, reverse longitudinally striated.

This beautiful species is chiefly remarkable for the degree of divergence with which the interstices branch,
and the small number of rows of pores. Length one inch, width one and a half inches; the interstices are
about one line apart and halfa line thick.

Potypora MARGINATA. M‘Coy. (Pl. XXIX. fig. 5).

Sp. Ch.—Interstices thick, irregularly bifurcate ; sides margined ; dissepiments thin; fenestrules small, elon-
gate, oval, or approaching to a square form; reverse with direct, deep, longitudinal striz; poriferous surface,
with five alternating rows of pores, and interjacent, waved striz.

The broad, flat, margin of the branches distinguishes this rare species at a glance from any of the other
corals likely to be confounded with it.

Potypora PAPILLATA. M‘Coy. (Pl. XXIX. fig. 10).

Sp. Ch.—Interstices rarely bifureating, very narrow, rounded; dissepiments thin, rounded; fenestrules cir-
cular or oval; poriferous surface smooth, with three alternating rows of pores; reverse smooth, with a small,
papillated pore at the origins of most of the dissepiments.

This species is remarkable for its large and round fenestrules, which are of such a size that the iterstices
and dissepiments appear disproportionably thin. The prominent pores on the outer side have caused me to
doubt the propriety of placing this coral in the same genus with the preceding species. It is very rare.

Porypora verrucosa. MM‘Coy. (Pl. XXIX. fig. 6).

Sp. Ch.—Interstices rarely bifureating, regular, equal, rounded ; dissepiments thin, distant ; fenestrules rec-
tangular, five times as long as wide, about one-third wider than the interstices, equal; obverse with four rows

of prominent, wart-like pores, about ten in each row to the length ofa fenestrule; between the pores are waving,
longitudinal striz ; reverse nearly smooth.

CARBONIFEROUS FOSSILS OF IRELAND. 207

This coral is very remarkable as being the only species of Polypora yet known with prominent pores; they
are so prominent in the specimen figured as to resemble the wart-like pores of some of the Gorgoni@ ; the spaces
between them are marked with coarse, waving striz; the fenestrules are very regular, long and narrow.

Rererora prisca. Gold. (Not Fenesteria prisca. Lonsd.)

Very imperfect specimens, probably referrible to Retepora prisca of Goldfuss, have occurred ; they belong,
of course, to the genus Fenestella, but not to the Silurian F’. prisca.

Rererora unpata. M‘Coy. (Pl. XXIX. fig. 11).

Sp. Ch.—Irregularly cup-shaped ; interstices anastomosing, flattened ; fenestrules ovate, pointed at one
end; poriferous face with five or six rows of pores in quincunx ; reverse with waved, or seale-like, semicircular
ridges.

This fine species is not uncommon. The specimens figured exhibit the longitudinal central axis of

attachment.

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