PECTEN. 



19T 



white, smooth, glossy, with minute radiating lines not correspond- 

 ing to the exterior grooves. Length, five inches ; height, five and 

 one half inches ; breadth, one and one half inches. 



This shellis not common on the Massachusetts shore; but single 

 valves, of a very large size and very solid, are occasionally thrown 



Fig. 494. 



P. teiiiiicostatus. 



up, and smaller ones are found in the stomachs of fishes. Its proper 

 habitat is farther north, and along the eastern part of the coast of 

 Maine it is found abundantly in its greatest perfection. It does oc- 

 casionally pass to the south of Cape Cod (the usual terminus for 

 northern species), for I have a fine specimen which was drawn up 

 alive by a hook, off Block Island. Eastport {Cooper^; Nahant 

 Beach, alive (Haske/I) ; Sable Island (^Willis). 



The general aspect of the lower valve is smooth ; nor do we see 

 anything like ribs on the upper surface. 



