Notes on Species of Corliculadce. 



235 



are thick, and the color of the interior is white. The strise are 

 irregular. The epidermis is dark green. The hinge is broad 



and angular. 



Fig. 65. 



Cyrena triangularis. 



The remarkably triangular outline of this species renders it 

 very distinct from all others of the same genus. 



Genus VELORITA. 



Cyrena, Gray, 1825.— Venus, Gray, 1828.— Velorita,* Gray, 1834. 



Animal. Not observed. 



Shell trigonal, higher than broad, heart-shaped, thick, in- 

 flated, posteriorly angular ; hinge broad, thick, three unequal 

 cardinal teeth, compressed, somewhat oblique, anterior tooth in 

 the right valve very short, posterior tooth in the left valve obso- 

 lete ; lateral teeth very unequal, anterior tooth thick, short, 



* Griffith's Cuvier, p].?l, f. v. 1834. 



