40 



PvBESCENS. My a pubefcens. P/iIt- Cat. Dorfet. p. 27. 



Mya declivis. Br. Zool No. 15 ? 



Tiirt. Lin. iv. p. 175. 

 Do7i. Br. Shells, iii. t. 82. 



M. with a very thin brittle, oval, white, fliell, trun- 

 cated at the fmaller end: in the larger fpecimens the 

 outfide appears, through a magnifier, foniewhat like 

 fliagreen, and is very rough to the touch ; flightly flrj- 

 ated concentrically : behind the cartilage Hope one valve 

 turns upwards in a fingular manner, and embraces the 

 edge of the other valve: the beak is nearly central, point- 

 ed, and turns a little fideways : hinge furniflied with one 

 broad tooth-like plate proje6ling inwards in each valve, 

 to which the conneftinsr cartilacje is fixed. Infide white 

 and glofiy. In young Ihells ib.c tecih arc not very con- 

 fpicuous, nor the outfide fo rough. 



This fpecics is not uncommon, of a fmall fize, taken 

 up with fand from Falmouth Harbour: fometimes met 

 with on the DevovJIiire coaft ; one we received from Ply- 

 mouih, taken by dredging was two inches broad, and one 

 inch and a quarter long. Doctor Pulteiviey (who fays 

 this fliell was firfl noticed by the late Dutchefs Dowager 

 of Portland) (peaks of having fecn it two inches and a 

 half long, and three inches and three-quarters wide: 

 dredged up at Weymouth. 



We 



