806 PALEONTOLOGY OF NEW YORK. 



This species is much smaller than any form here described. It somewhat 

 resembles G. truncata, but differs in its greater proportional height, the area 

 between the carina and hinge-line is more convex; the concentric striae are 

 much stronger and the indications of radiating striae are quite obscure. 



Formation and locality. At the base of the Clieniung (Ithaca group) at Ithaca, 

 N. Y. 



