74 
Inhabits the coast of the United States. Length two inches. 
Cabinet of the Academy, and Philadelphia Museum. 
Seems to differ from the species as described by Koissy in Sonni. 
Buff, by having lateral lineations instead of spots. It may very 
probably be a distinct species. 
Crepidula depressa.^ — Shell very much depressed, trans- 
versely wrinkled, nearly equilateral ; epidermis pale yellowish- 
brown ; apex not curved, forming a simple acute terminal angle 
upon the margin of the aperture ; aperture subovate ; within white ; 
diaphragm convex, edge contracted in the middle and at one side 
Length four-fifths of an inch. Inhabits the coast of the United 
States. 
Cabinet of the Academy, and Philadelphia Museum. Differs 
from the preceding in the form of the beak, which is never 
arquated. 
Crepidula glauca. — ^Shell thin, convex, glaucus, with minute 
transverse wrinkles ; apex conic, acute, not excurved, but declining 
and distinct from the margin of the aperture ; aperture oval-orbi- 
cular ; within entirely reddish-brown ; diaphragm plain or convex, 
less than half the length of the shell, edge widely contracted in 
the middle. 
Length about half an inch. Inhabits the coast of the United 
States. 
Cabinet of the Academy and Philadelphia Museum. V ery dis- 
tinct from the preceding species. 
Crepidula plana. — Shell depressed, flat, oblong oval, trans- 
versely wrinkled, lateral margins abruptly deflected ; apex not 
prominent, and constituting a mere terminal angle, obsolete in the 
old shells ; within white ; diaphragm occupying half the length of 
the shell, convex, contracted in the middle and at one side. 
Length one and one-tenth of an inch. Inhabits the coast of the 
United States. Cabinet of the Academy and Philadelphia Museum. 
A remarkably distinct species, the surface of the shell is flat, 
and sometimes slightly concave. The young shell is generally or- 
bicular, and gradually becomes proportionally more elongated as it 
increases in size. I have found it on the coasts of Maryland, 
Carolina, Georgia and East Florida, and my brother, Mr. Benjamin 
Say, discovered it on the shores of New Jersey. 
Crepidula intorta ? var.^ — Shell convex, ovate, with about 
