CRUSTACEA 239 



Common on the rocky shores of New England 

 in shallow and deep water Not frequent in New 

 Jersey, although occasionally seen with the more 

 common C. irroratus, especially in the northern part 

 of the State. Rare south of New Jersey but found in 

 deep water as far south as Florida. 



Pinnotheres ostreum Say (Oyster Crab) 



PLATE XXV. Fig. 8 



Carapace nearly circular, somewhat membrane- 

 ous; surface smooth and white; rarely more than 

 % inch across the carapace (female). The females 

 live as commensals in the mantle cavity of oysters; 

 the males are very minute and are free swimming. 



The females are frequently found in oysters 

 taken from New Jersey waters, and in fact, are 

 eaten with the oysters; the males are seldom seen. 

 Known from Massachusetts to Florida and the West 

 Indies. 



Pinnotheres maculatus Say (Mussel Crab) 



PLATE XXVII. Fig. 8 



Carapace slightly firmer than the above and 

 covered with a hairy growth; females about the 

 size of the above; males smaller than the females, 

 but not as small as the males of P. ostreum. Females 

 commensal in the shells of the Mussel (Mytilus edulis) 

 or other bivalves; males either free swimming or 

 commensal. 



