MYA. 171 



valve. Between them lies the rich brown cartilage, for 

 the reception of which there is a shallow indentation on the 

 external surface of the greatly projecting tooth. Neither 

 the cartilage receptacle in the right valve, nor the opposing 

 tooth of the left, can be termed simple ; there being a 

 broad ledge-like anterior detached margin to the former, 

 whilst the posterior scarcely elevated linear tooth forms 

 a lateral denticle near the base of the latter, which, more- 

 over, is decidedly convex internally, with its apex arcuated 

 and its front almost rectilinear or truncated, and bending 

 over so as to form a margin for the cartilage on that side. 

 The inner surface is white and often glossy, and the sinus 

 of the palleal scar, which is rather remote from the margin 

 and a little undulated in its impression, is elongated and 

 narrow. 



The animal of this species in its general features 

 resembles the last. When stripped of its epidermis it is 

 of a yellowish- white colour, the orifices tinged with red. 



The average size of the shell is about four inches long 

 and two and a third broad, but examples are often found 

 of much larger dimensions. Although locally abundant, 

 for it is a gregarious species, and tolerably diffused through- 

 out our coast, it is less" frequently met with, especially in 

 fine condition, than might be imagined. It is dug out of 

 a gravelly, sandy, or clayey bottom near low water mark, 

 usually in or near estuaries, and is found, among other 

 spots, at Heme Bay in Kent (S. H.); "Portsmouth, the 

 Isle of Wight, Southampton" (Jeffreys"' cab. and M'An- 

 drew), where, according to Montagu, they are called "old 

 maids," and are sometimes collected for food ; Tenby in 

 Pembrokeshire (S. H.) ; Red Wharf Bay, Mackruss, Borth 

 (Eyton); "in suitable localities on every side of the Irish 

 coast" (Thompson); Dublin Bay and Cork Harbour (Jeft- 



