PlJ.LASTRA. 
COXCHIFERA. 
203 
F. scalar-is . Sowerby, V. pi. 146, p. 490, fig. 3. 
A little elongated; nearly straight, and sub-triangular; 
slightly compressed ; beaks obtuse, and nearly central; car¬ 
dinal teeth long and thin ; surface with about twenty very 
flat, straight, divergent ribs, crossed by fine concentric stria); 
internal margin denticulated. 
The Red, and also the Coral Crag, Sutton. 
3. Venericardia citamaeformis. —The Chama-formed 
Venericardia, pi. LXXXIII. fig. 29. 
F. chaniaeformis. Sowerby, V. p. 145, pi. 496, fig. 1. 
Oblong; convex; a little acuminated towards the beaks, 
which aro slightly curved and produced, with about four¬ 
teen large, rugged, prominent, distant ribs, with flat, inter¬ 
vening furrows. 
The Coral Crag, Sutton. 
4. Venericardia deltoidea. —TheDeltoidal Venericardia, 
pi. LXXXIII. fig. 34. 
F. deltoidea. Sowerby, III. p. 106, pi. 259, fig. 1. 
Deltoidal; a little oblique ; hinge very strong; surface with 
about twenty almost smooth, carinated, curved, longitudinal 
ribs; lunette small and obsolete; internal margin crenated; 
hinge remarkably strong. 
The London Clay, Barton and Lyndhurst. 
5. Venericardia acuticosta. —The Sharp-ribbed Veneri¬ 
cardia, pi. LXXXIII. fig. 32. 
V. carinata. Sowerby, III. p. 106, pi. 259, fig. 2. 
Transversely oblong; gibbose ; beaks very large and ob¬ 
tuse ; lunette obsolete ; a little indented below the beaks ; 
surface with about twenty almost smooth, prominent, curved, 
carinated ribs ; internal margins denticulated. 
The London Clay, Bracklesham Bay; Stubbington and 
Barton. 
6. Venericardia globosa.— The Globular Venericardia, 
pi. LXXXIII. figs. 30, 31. 
V. globosa. Sowerby, III. p. 161, pi. 289, upper and 
middle figs. 
Globular; beaks rather largo and obtuse; surface with 
from fifteen to twenty carinated, strong, curved ribs, the ca- 
rinse being provided with compressed tubercles; inner mar¬ 
gin strongly denticulated. 
The London Clay, Barton and Ilordwell. 
7. Venericardia oblonga.— The Oblong Venericardia, pi. 
LXXXIII. fig. 26. 
V. oblonga. Sowerby, III. p. 162, pi. 289, three lower 
figures. 
Transversely oblong ; sub-quadrangular; gibbous ; oblique ; 
sides unequal; surface with eleven to thirteen strongly tuber- 
culatcd, curved, distant ribs; internal margin with large 
crenulations. 
Tho London Clay, Barton. 
8. Venericardia orbicularis. —The Orbicular Veneri¬ 
cardia, pi. LXXXIII. fig. 27. 
V. orbicularis. Sowerby, V. p. 145, pi. 490, fig. 2. 
Orbicular, rather convex ; surface with about sixteen cren¬ 
ated, longitudinal ribs ; the intervening furrows concentrically 
striated ; hinge small. 
The Red Rag, Sutton. 
9. Venericardia senilis. —The Aged Venericardia, pi. 
LXXXII. fig. 33. 
F. senilis. Sowerby, III. p. 105, pi. 258. 
Obliquely heart-shaped, convex ; hinge very strong; sur¬ 
face with from sixteen to eighteen strong, sub-imbricated 
ribs; lunette obsolete; substance of the shell thick; internal 
margin crenulated. 
The Red Crag, Sutton, and the Coral Crag, Ramshot. 
10. Venericardia tenuicosta. —Tho Thin-Ribbed A"ene- 
ricardia, pi. LXXXIII. fig. 25. 
V. tenuicosta. Geo. Trans. 2d Ser. IV. p. 335, pi. 11, 
fig. 7*. 
Nearly orbicular, or slightly quadrangular; convex, and 
somewhat heart-shaped ; surface with numerous fine longitu¬ 
dinal ribs, crossed by strong stria), which make the ribs feel 
rough to the touch ; lunette oblong, rather hollow ; posterior 
side slightly even ; internal margin crenulated. 
The Gault, Folkstone, and Vale of AVardour. 
Genus XXVIII.—PULLASTRA.— Sowerby. 
Shell equivalve, inequilateral, the anterior side being the 
shorter; three cardinal teeth in each valve, situate near to 
each other, and generally within a notched or cleft termina¬ 
tion ; and in a few species the central tooth is deeply so ; two 
lateral, somewhat rounded, muscular impressions; pallial im¬ 
pressions with a large sinus; ligament external, and partly 
concealed by tho dorsal margins of the valves. 
1. Pullastra l/evis.— Smooth Pullastra, pi. LXXXIII. 
fig. 7. 
P. lewis. Sowerby, Silur. Syst. pt. II. p. 602, pi. 3, 
fig. la. 
Shell transversely elongated, a little convex, smooth, plain ; 
beaks very small; anterior side short; posterior side large, 
somewhat flattened or sub-truncated, and nearly parallel with 
the hinge-line ; length three quarters of an inch ; breadth one 
inch and a quarter. 
In the lowest beds of the Old Red Sandstone, at Iloreb 
Chapel, AVales. 
2. Pullastra complanata. —The Smooth Pullastra, pi. 
LXXXIII. fig. 8. 
P. complanata. Sowerby, Silur. Syst. pt. II. p. 609, pi. 5, 
fig. 7 . 
Shell transversely elongated, its width being double its 
length, compressed, smooth ; anterior side short and rounded ; 
posterior side long and sub-acute, with an oblique edge ; 
beaks obtuse, and placed near the anterior side ; length three 
quarters of an inch; breadth an inch an a half. 
The Upper Ludlow Rock, Darley Brook, Linley, near 
Bridgenorth. 
3. Pullastra perigrina. —The Marsh Pullastra, pi. 
LXXXVIII. figs. 1, 2. 
Unio peregrinus. Phillips, Geo. York, I. p. 115, pi. 7, 
fig. 12. 
Ovate ; beaks rather obtuse, and somewhat remote ; hinge- 
line oblique; anterior side short; posterior side long; both 
extremities rounded ; basal line gently arcuated; back gra¬ 
dually sloping downwards; surface smooth, with a few well- 
marked concentric furrows. 
