38 



7. 

 ANEjQUF.VALVis. Cardium llnatum apicibus reflexis. IFalk. Min. Shells, fig. 85. 



M. with a fub-triangular, ftrong, thick, opaque, white 

 (hell, frequently covered with a brown epidermis : under- 

 valve deep ; beak central, prominent, (landing high above 

 the hinge, furnifhed with one flrong, erect tooth fome- 

 what recurved : Infide fmooth, the margin appearing as 

 if ground to an edge. 



Upper valve not half the fize of the other, fmooth, but 

 radiated with a few obfolete fbiac from the beak : at the 

 hinge a notch to receive the tooth of the oppofite valve. 

 When clofed the margin of the under valve projetls con- 

 fiderably. 



The fingular formation of tliis fhell is not well defined 

 by Walker, poffibly he had never feen the perfeft fliell : 

 indeed the fuperior valve might readily be miftaken for 

 a diftinft fpecies ; he has alfo erred in making it a 

 Cardium. 



This fhell is by no means uncommon ; but rarely to be 

 obtained alive, or with connefted valves ; we have found 

 it on the coafts of Cornxoall and DevonJJdre, and in a 

 living Hate dredged from Salcomb-bay. Mr. Boys fa- 

 voured us with the under-valve from Sandwich for Wal- 

 ker's (hell here quoted. Diameter rarely above three- 

 eighths of an inch. 



M. with 



