CONCHIFERA OR BIVALVES. 



63 



found, they are not uncommonly eaten. When 

 the animal is irritated, it is said to throw out a 

 stream of water to a considerable distance. 



This genus inhabits the European, Ame- 

 rican, and Indian seas. 



The animal is phosphorescent. This fact 

 is mentioned by Pliny, as well as by modern 

 authors. 



Family 3. — Solenidce* 



The shells of this family are usually long, 

 gaping at both ends, and having the valves 

 united by an external ligament. The animals 

 do not bore into wood or stone, but bury 

 themselves in the sand. — There are 6 genera. 



13. Solen. — Shell generally very long, 

 straight, or arched, both ends open, and equi- 



valve; teeth small, and varying in number; 

 ligament exterior; bosses small. Animal hav- 

 ing a short tube, containing two others united, 



* Les Solenacees, Lamarck. 



