PHOLAS. 



37 



Fis 3G3. 



the sole of a shoo ; the supplementaiy valve is cartilaginous (not 

 calcareous), spear-shaped, pointing forwards. 



This well-known species is admitted into our catalogue, from the 

 fact that Professor Adams 

 has lately discovered an ex- 

 tensive l)ed of dead shells at 

 New Bedford. It prol)al)ly 

 is not to be found in a living 

 state in our waters. Indeed, 

 I am not aware that it is 

 found living on the shores 

 of any of the Middle or East- 

 ern States. It is fouml at 

 the above locality, of all sizes 

 and ages, its most delicate 

 portions entire, forbidding 

 the idea that these shells 

 were transported by any 

 means from some distant lo- 

 cality. It is certainly re- 

 markaljle, that a large sliell 

 should have been abundant 

 at no very distant period, 

 Avhicli cannot now be found 

 living within one or two thou- 

 sand miles. Something of 

 the same kind is said to 

 belong to the history of 

 the oyster about Cape Cod. 



[With no little surprise, 

 I received (Nov. 26, 1845) 

 from Thomas A. Greene, of 

 New Bedford, a jar contain- 

 ing three living specimens 

 each of P. costata and P. 

 tnmcata^ wliich were brought 

 up by the mud-machine at 

 the end of the Long Wharf 

 in that place. From the 

 number obtained in a short time he supposes they must l)e plentiful. 

 He thinks they burrow two or three feet below the surface. 



p. costala. 



