320 MARINE SHELLS 



Thickness eleven- twentieths of an inch. 



Inhabits the coast of North America. 



Cabinet of the Academy and Philadelphia Mu- 

 seum. 



This shell, which has very much the aspect of a 

 Pholas, is not uncommon, but is more abundant on 

 the southern coast. It approaches P. pholadiformis 

 of Lamarck, but differs in not being " subglabrous 

 before." 



PHOLAS, Lin. Lam. 

 Species. 



1. P. ^oblongata. Shell thin, white, transversely 

 much elongated ; basal and hinge margins nearly 

 parallel ; anterior and posterior margins rounded ; 

 valves transversely and longitudinally striated, the 

 strise muricated and elevated upon the anterior side 

 into costse, which are more prominently and densely 

 muricated ; hinge callous polished, minutely striated 

 transversely and longitudinally, and with about 

 twelve cells, anterior to which is a recurved margin 

 of the shell, forming a cavity ; dentiform process di- 

 lated, incurved, spoon-shaped, emarginate on the 

 posterior side, and irregularly truncated at tip. 



Greatest length, one inch and one-fifth. 



Breadth, four inches and two-fifths. 



Inhabits Georgia, Carolina, and East Florida. 



