472 
PALAEONTOLOGY OF NEW YORK. 
Cardinal line concave. Anterior end short, obliquely truncate above and 
narrowly rounded below. 
Valves depressed-convex in the posterior and lower portions, becoming- 
gibbous in the middle and umbonal region. 
Beaks at about the anterior fourth, prominent, strongly incurved and ris¬ 
ing above the hinge-line. Cincture indicated by a gentle, undefined depres¬ 
sion, extending from the beaks downward, producing a slight sinuosity in 
the basal margin. Umbonal slope angular above, becoming less prominent 
below and extending to the post-inferior extremity. Post-cardinal slope 
broad, marked by a more or less distinct longitudinal fold. 
Surface marked by tine concentric striae, which become fasciculate on the 
anterior and posterior portions of the shell, and by radiating striae which 
cover the body of the shell posterior to the beak, occupying the space from 
the anterior side of the cincture to the umbonal ridge. 
Lunule marked by an abrupt infolding of the shell, leaving an angular 
margin. 
Two specimens measure respectively 60 and 70 mm. in length, and 27 and 
31 mm. in height. 
This species is distinguished by its large size and strong radii which cover 
the body of the shell. In its general form and expression it is very similar to 
some varieties of Cimitaria recurva. 
Formation and, locality. In the sandstones of the Waverly group in Licking 
county, Ohio. 
