Winchcll.] 
256 
[Jan. 4, 
little below the level of the straight indented hinge line. The greatest 
thickness of the shell is therefore near the flattened dorsal border. From 
this ridge the lateral surfaces proceed with slight curvature to the ventral 
margin, so that the united valves present a cuneate or somewhat axe-like 
form. 
Length, one inch ; height, thirteen-sixteenths ; transverse diameter, 
nine-sixteenths. 
This species is less elongate than Cypricardia rigida , and has a round¬ 
ed, instead of truncate posterior extremity ; the umbonal ridge, also, is 
nearer the hinge margin. 
Collected by Rev. H. Herzer, at Newark, Ohio. 
Sangijinolites Maushallensis, Win. 
Occurs in bed No. 4, Sciotoville, Ohio. 
Allorisma (Sedgwickia) Hannibalensis, Slium. (Mo. Rep. p. 206). 
Specimens from Newark, Ohio, agree better with the Burlington (Iowa) 
forms usually referred to this species, than with Dr. Shura ard’s figure of 
the type, - 
Cypricardia (?) rigida, W. & W. (Bos. Proc. "VIII, 300.)' 
A single specimen from Newark, Ohio, which does not show the “second 
ridge” between the main umbonal angle and the hinge, and which may 
result frpm dorso-ventral compression. 
Leda bellistriata ? Stephens (Am. Jour. Sci. [2] vol. XXV, p. 26.) 
Five specimens from dark, bituminous Shales, Tennessee, are referred to 
this species solely on account of external resemblances. They have the 
peculiar form and sharp concentric furrows of the species. They are a 
little over an inch in length, but do not, in this, exceed specimens from 
Battle Creek, Michigan,—the typical locality. At the same time, no in¬ 
dication of hinge-structure has been observed, and the shell seems to have 
been thinner than usual for the species of this family. Should further 
discovery demonstrate that these specimens do not belong to Leda , they 
will perhaps fall into the genus Sedgwickia of McCoy ; but I do not con¬ 
sider it allowable to propose a specific name to be based on discoveries of 
some future investigator. 
Conocarditjm PULCHELLUM, White & Whit. (Proc. Bos. Soc. N. H. 
VIII, 299. ) From Newark, Ohio. 
Solen scalpriformis, Win. (Proc. Acad. N. S., Phil. Sep., 1862,- p. 
428.) From dark, bituminous shales, Tennessee. Like other species in 
the same situation, the shell is thin and fragile. This probably resulted 
from an insufficiency of calcareous matter in the waters which precipi¬ 
tated the argillo-bituminous materials of the rock. 
Solen QUADRANGULARis, Win. (Proc. A. N. S., Phil. Jan., 1862.) A 
fragment from Granville, Ohio. 
Platyceras Herzeri, n. sp. 
Shell rather large, consisting of about two coils, which enlarge rapidly 
near the apex, and gradually through the last half of the whorl; laterally 
compressed, and dorsally sub-angulated, except near the aperture ; irre¬ 
gularly plicated longitudinally, and marked transversely by deeply waved, 
