1870.] 
255 
[Winch ell. 
Perropecter limattts? Win. (Proe. A. N. S., P., July, 1805, p. 126.) 
Newark, ancl bed No. 4, Seiotoville, Ohio. 
Like the other Ohio representatives of the species of this family, the 
specimens of this species are considerably larger than the Iowa types. 
Aviculopecter Newarkersis, n. sp. 
Dorso-ventral and antero-posterior diameters and length of hinge line as 
the numbers, 14, 10 and 7. Left valve rather convex, its cardinal slopes 
forming an angle of about 60°, and thus creating a sharper beak than is 
usual in this genus. Anterior ear somewhat inflated, with about six 
strong radiating striae, finer intermediate ones, and numerous fine decus¬ 
sating striae. Posterior ear a little smaller, flat, its posterior boundary 
nearly at right angles with the hinge. Beak scarcely exceeding the hinge. 
Surface marked with numerous fine, unequal, slightly wavy, delicately 
crenulated, radial striae. 
Dorso-ventral diameter fourteen-sixteenths of an inch ; antero-posterior, 
ten-sixteenths ; length of hinge line, seven-sixteenths. 
The striae are of the size of those in A. tenuicostus , Win., but they are 
less rigid, regular and uniform ; the shell is. less circular, and the umbo 
is more prominent. 
Aviculopecter Caroli, Win. (Proc. A. N. S., Phil., Jan., 1863, p. 9.) 
From Newark, bed No. 4, Seiotoville, and from Granville, Ohio. 
The specimens from Licking county are all right valves, and are much 
flatter than typical specimens of the same valve. 
Aviculopecter occidertalis, Win. (Proc. A. N. S., Phil., Jan., 1863, 
p. 9.) From Newark, Licking county, Ohio. The largest specimen is 
twice the size of the Iowa types. A right valve of the same size, from 
Granville, shows also obsolete, irregular, radiating furrows around the 
margin of the cast. 
Sarquirolites raiadiformis, n. sp. 
Length two and a half times the height; laterally flattened below the 
umbo ; dorsal and ventral margins parallel or nearly so—the ventral 
sometimes with a broad shallow sinus extending upwards over the valves 
and vanishing near the umbo ; a distinct umbonal ridge flattening out 
near the postero-ventral angle, at which place the outline presents a 
rounded angulation ; the postero-dorsal slope making, with the dorsum, 
an angle of 45°. 
Length, 2y inches ; height, one and one-sixteenth inches ; thickness, 
half an inch. 
The above description is based on a specimen from Hillsdale, Michigan. 
Mr. Herzer has sent a single specimen from Newark, Ohio, which agrees 
with this ; but such is the state of preservation of lamellibranchs in this 
formation, that there is extreme difficulty in ascertaining their generic 
characters. Another specimen from Granville, Ohio, presents a still bet¬ 
ter specific accordmice. 
Sarguirolites (Cypricardia?) securis, n. sp. 
Outline of shell sub-oval, anteriorly indented by a small lunule, over 
which hangs the small, incurved, approximated, sub-terminal beaks. A 
very prominent, sub-acute ridge runs from the beaks posteriorly and but 
