74 



Inhabits the coast of the United States. Lengtli two inches . 

 Cabinet of the Academy, and Philadelphia Museum. 



Seems to diifer from the species as described by Roissy 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 v?rinkled, 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, glaueus, 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. Very 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 



