CONCHIFERA OR BIVALVES. 57 



8. Fistulana. — Shell, valves equal, free, 

 and situated inside the tube, 

 which is swollen and closed 

 at one end, but thin and 

 open at the other. Animal 

 not well known. — 4 species 

 recent, and 2 fossil. 



This genus is found 

 buried in wood or fruits 

 which have been long in the 

 sea, in the thick substance 

 of other shells, and also in 

 the sand. Its locality is the 

 shores of India. 



Lamarck here places two 

 genera, Septaria and Tere- 

 dina, which modern natu- 

 ralists think unnecessary. 

 Deshayes unites them to 

 Teredo. 



Reeve, in his Conchologia Systematica, ar- 

 ranges Gastrochcena in this family, as it lines 

 with a testaceous tube the cavity in which it 

 dwells. It also forms an unconnected tube for 

 protection when not imbedded. 



