CLASS PELECYPODA 
129 
Type in U. S. N. M. Type locality, Cape San Lucas, Lower California. 
Range. Monterey, California, to Cape San Lucas and Ecuador. 
Family LEPTONID^E 
Genus ERYCINA Lamarck, 1806. 
Shell equivalve, subinequilateral, usually transversely oval; one or 
two unequal, diverging cardinal teeth, separated by a pit; lateral teeth 
oblong, compressed, short; ligament external and internal; muscular im¬ 
pressions rounded, pallial line simple. 
Range. Pacific. 
Range in time. Cretaceus, Eocene of North America and Paris 
Basin. 
Erycina catalinas Dali, 1916. 
Proc. U. S. N. M., 52:409. 
Shell small, inequilateral, the anterior side shorter, rounded, the base 
nearly straight; posterior side also rounded, slightly attenuated, the 
dorsal slope convex but descending; hinge strong, the teeth well developed; 
the beaks well developed, not prominent, the surface smooth except for 
faint incremental lines, covered with a light yellowish-brown dull perio- 
stracum. Length, 2.5 ; height, 2; diameter, .2 mm. (Dali.) 
Type in U. S. N. M., No. 210879. Type locality, Catalina Island, 
California. 
Range. Known only from the type locality. 
Erycina coronata Dali, 1916. 
Proc. U. S. N. M., 52:409. 
Shell small, white, rounded quadrate, nearly equilateral, the surface 
finely concentrically striated; basal margin nearly straight; ends rounded, 
the posterior a little produced basally, the dorsal slopes similar, slightly 
descending, with at each end two or four minute elevated spinules. Length, 
4; height, 3; diameter, 1.2 mm. (Dali.) 
Type in U. S. N. M., No. 225193. Type locality, off the Coronado 
Islands, Lower California. 
Range. Known only from the type locality. 
Erycina bakeri Dali, 1916. 
Proc. U. S. N. M., 52:410. 
Shell small, white with a pale yellowish periostracum, subquadrate, 
inequilateral, the anterior end shorter; hinge line short, straight, at the 
outer extremities usually a small spinule, beaks pointed, the prodissoconch 
