CONCHOLOGIA CESTRICA. 89 
U. ochraceus, Say, Nich. Encyc., 1st Amer. Ed., 1816. 
U. ochraceus. 
Fig, 184. 


Shell, thin, thicker anteriorly, translucent, pale yel- 
lowish, or reddish; radiate with dull green, and with 
minute wrinkled radii, most observable on the posterior 
slope; sub-ovate, hinge margin rectilinear, anterior and 
lower, rounded, posterior oblique-truncate, angular ; 
beaks undulated; within bluish; cardinal teeth double, 
much compressed, almost horizontal. H. 2, W. 3.5, T. 
1.5, inches. 
Station, with the preceding. 
U. Tappanianus, Lea, Tr. Amer. Ph. Soct., VI., 1817. 
U. Tappanianus. 
Fig, 185. 

Shell, thin, sub-oval, rather inflated, elevated back of 
8 * 
