CONCHIFERA OR BIVALVES. 79 



nerally in each valve ; ligament exterior. Ani- 



mal, foot compressed and 

 long. — 8 species recent, and 

 2 fossil. 



The Venerupis excavates 



stones and corals : it is found on the coasts of 

 England, France, the countries washed by the 

 Mediterranean, &c. The colour is a dirty 

 white. 



By some authors this genus is not admitted. 

 Sowerby says they do not bore into the 

 rocks, but are merely cast into the cavities in 

 which they dwell, by accident. He unites 

 them to the Veneridce, under the name of 

 Pullastra. 



Family 7. — Nymphidce* 



Many of the genera of this family comprise 

 very beautiful shells, being smooth, polished, 

 and tinged with shades of pink, orange, &c. 

 They are usually oblong, and rather more flat- 

 tened than the preceding families. The liga- 

 ment is always external, and supported by a 

 thickened hinge-plate, (called a nympha, or 



* Les Nymphacees, Lamarck. 



