48 BIVALVES. — CHAM A. 



stones, and various shells; liovv ever, they in many instances 

 seem to give a preference to some particular genus of 

 shells, for the Chama arcinella is more commonly found 

 affixed to that species of murex called the thorny wood- 

 cock, than to any other body known. However, it retains 

 a partiality for others of the murices, especially those 

 often known under the name of triplices. The Ameri- 

 can, Indian, and Atlantic Oceans; and the Mediterranean, 

 Caspian, and Adriatic Seas, all produce infinite varieties 

 of this genus. The Chama Foliacea is found fossil ia 

 Campania, 



CHAMA.— Clam. 



A. Closed. 

 *Cor. (FooVs Cap C. ; Cockle.) Bicornis. 

 Moltkiana. Arcinella {Hedge-Hog) 

 Hippopus (Bears Paw Clatnp.) Concamerata. 

 Autiquata. Macerophylla. 

 Trapezia, Foliacea. 

 Semiorbiculata. Arata. 



Calyculpta. Fusca. 



Cordata. Citrea. 



Sal lata. Thaca. 



Oblonga. Rugosa. 



l.azarus. Gryphica. 



Gryphoide's. C^oralliophaga. 



B. Gaping. 



Gigas {Fnrbelow'd Clamp, Giant Clam.) 



