16 BIVALVES — MYA. 



The greatest part of them are covered with a thick 

 brown or green epidermis; when this is removed, 

 and the shell polished, brilliant prismatic hues are 

 displayed. 



In some places the Mya constitutes a considerable 

 portion of food for man, birds, &c. They have a pro- 

 pensity to burrow in the sand and mud, in which they 

 are wholly or partially concealed. 



The Mya is derived from nva^, which was applied 

 by the antient naturalists to the genus Mytilus. 



Division I. — Hinge with one or two rounded teeth, not inserted m 

 the opposite valve. 



Some species of this division grow to a large size, 

 as the M. glycymeris. 



Scientific Name. Localities. Cammon Name. 



Glycymeris Mediterranean Sea, Spain, Great Gaper •• 



Portugal, and Naples • • 



Truncata Europe, Britain Abrupt • • • do 



Arenaria Ditto Sand do 



Declivis Devonshire,Weymouth • • Sloping • • • do 



Pubescens Ditto Pubescent • • do 



Praetensus • • • • < • • Britain Spoon-hinge do 



Anatina Mouth of the Niger Duck do 



Globosa Globular • • do 



Nicobarica ...... Nicobar Islands Nicobar • • • do 



Rostrata Bergen Beaked do 



Distorta Plymouth Deformed- • do 



Bidentata Devonshire Double-toothed do 



Decussata'' Frith of Forth Decussated do 



Purpurea Devonshire • • Purple • • • • do 



Ferruginosa Belton Sands, Dunbar • • • Rusty do 



Nitens Glossy do 



Prismatica Scotland, Devonshire- • • • Prismatic • • do 



Substriata Devonshire Substriated do 



