202 
CONCHIFERA. 
Vexlkic ardia. 
5. Pleuroriiynciius lonc.ipennis. —The Long-Winged 
Pleurorhynchus, pi. LXXXII. fig. 10. 
Transversely and much elongated; hinge-line nearly 
straight ; body doltoidal, with fine radiating striae, crossed by 
some irregular thin lines of growth ; centre of the valves 
rising into a prominent keel-shaped projection, which emanates 
from the beaks, on which portion the stria? are double, and 
much closer than towards the sides; rings, consisting of 
greatly lengthened, smooth, wing-shaped processes, that on 
the anterior sido shortest, and acutely pointed ; tho other, 
broader throughout, and a little obtuse at its termination, and 
with a few nearly obsolete transverse ribs at its point; length 
not quite three-eighths ; breadth upwards of an inch. 
This beautiful shell is in the cabinet of my friend, Dr Fleming, of 
Broughton View, Pendleton, who found it at Dovedale, Derbyshire, in 
the Carboniferous Limestone. 
O. Pleurorhynciius min ax. —The Menacing Pleurorhyn- 
chu8,pl. LXXXII. figs. 1? and 25. 
P. minax. Phillips, Geo. York, II. p. 210, pi. 5, fig. 27. 
Pal. Foss. p. 33, pi. 17, fig. 00. Cardium alceforme . Sower- 
by, VI. p. 100, pi. 552, fig. 2, (the lower shell.) 
Deltoidal, transversely elongated ; gibbous anteriorly, with 
a contracted, slightly concave space around the umbo ; poste¬ 
rior side conically elongated; beaks anterior; surface with 
many equal, longitudinal, divergent ribs, except on tho cordi- 
form anterior space, where they are much fiuer than on the 
other portions, and are distinctly separated by tho ring which 
circumscribes the depression. 
The Carboniferous Limestone, Bolland and Kildare, and 
Devonian Rooks, Bradley and Ilalberton. 
7. Plf.uror iiYXCHUS trigonalis. —The Trigonal Pleuro- 
rhynchus, pl. LXXXII. figs. 12 and 19. 
P . trigonalis. Phillips, Geo. York, II. p. 211, pl. 5, 
figs. 30, 31, 32. 
Elongated, horse-hoof shaped ; gibbose anteriorly, with a 
short smooth wing ; oblique ; hinge-line nearly straight; pos¬ 
terior side elongated, and somewhat wedge-shaped ; obliquely 
obtuse at the termination, which, as woll as the body, is 
covered with many flat, divergent, longitudinal ribs. 
The Carboniferous Limestone, Bolland. 
Genus XXY.—CAR-DIOLA.— Broderip. 
Shell equivalve, oblique, inequilateral; beaks prominent and 
curved; hinge-line long, with a flat area; surface concentric¬ 
ally furrowed. 
Tho shells of this genus are highly characteristic of the 
lower members of tho Upper Silurian Rocks, and are spread 
over a wide extent of country. 
1. Cardiola fibrosa. —The Fibrous Cardiola, pl.LXXXII. 
fig. 31. 
C.Jibrosa . Sowerby, Sil. Syst. pt. II. p. Cl7, pl. 8, fig. 4. 
Cordiform ; beaks acuminated and elongated; slightly iu- 
curved ; upper portiou of the surface smooth, with a few con¬ 
centric furrows ; lower portion with longitudinal stria*, finely 
decussated by numerous transverse stria?. 
The Lower Ludlow Rock, Ludlow ; Welchpool, Maryknoll, 
Dingle, &c. 
2. Cardiola interrufta. —The Interrupted Cardiola, pl. 
LXXXII. fig. 32. 
C. interrupta. Sowerby, Sil. Syst. pt. II. p. G17, pl. 8, fig. 5. 
Ovately cordiform and sub-compressed ; beaks nearly cen¬ 
tral and short; surface covered with many deep concentric 
furrows, and more numerous longitudinal divergent ones, 
whioh are less deep than the others. 
Tho Lower Ludlow Rock, Breidden Hills ; Garden House 
Quarry, near Aymestrv; Radnor Forest, &c. 
Genus XXVI.—MYOCONCHA.— Sowerby. 
Bivalve, equivalve, oblique, sides very unequal; hinge with 
an elongated oblique tooth in the left valve, and provided with 
an external ligament, which is seated in a deep groove ; beaks 
placed close to the posterior extremity; destitute of a sinus in 
the impression of the mantle. 
I. Myoconciia crassa.— Thick Myoconcha, pl. LXXXIII. 
figs. 35, 36. 
M. crassa. Sowerby, V. p. 103, pl. 407. 
Longitudinally elongated; its length nearly twice its width; 
convex ; slightly curved, and pointed at tho beaks ; surface 
almost smooth, with a few concentric lines of growth ; sub¬ 
stance of the shell thick, and tho valves rather shallow. 
In the young condition there are three or four elevated strife crossed 
by lines of growth. 
The Inferior Oolite, Dundry and Brakenridge. 
Family V.—CONCITACEA. 
Sholls with three primary teeth at least in one valve, and 
the other generally with tho same number, but in some in¬ 
stances fewer. 
Sub-division I.—MARINE. 
Generally destitute of lateral teeth. 
Genus XXVII.—VENERICARDIA.— Lamarck. 
Shell equivalve, inequilateral, sub-orbicular, the surfaco ge¬ 
nerally with longitudinal radiating ribs or furrows; two oblique 
primary teeth, directed to tho same side; substance of the 
shell thick. 
1. Venericardia flanicosta. —The Flat-ribbed Vcneri- 
cardia, pl. LXXXIII. fig. 23. 
V. planicosta. Sowerby, I. p. 107, pl. 5. 
Somowhat heart-shaped ; rather smooth, with about twenty 
flat, broad, curved, longitudinal ribs, and narrow, shallow, in¬ 
tervening furrows; on the internal posterior margin a few 
large crenulations, which do not extend to tho margin ; beaks 
much incurved ; substance of the shell very thick and ponder¬ 
ous ; hinge very large and powerful. 
The London Clay, Blackdown. 
2. Venericardia scalaris. —The Ladder Venericardia, 
pl. LXXXIII. fig. 24. 
