MOLLUSCA. 79 



SUB-CLASS II. SIPHONIDA. 



ORDER I. *EUDIST^E. 



Fam. Hippuritidse. Hippurites. 

 ORDER II. CHAMACE^E. 



Fam. a. Chamidae. Chama, *Diceras. 

 Fam. b. Tridacnidae. Tridacna, Hippopus. 



ORDER III. CARDIACEA. 



Fam. Cardiidae. Cardium (Cockle), Hemicardium. 

 ORDER IV. LUCINACEA. 



Fam. a. Lucinidse. Lucina, Corbis. 



Fam. b. Cyprinidse. Cyprina, Isocardia. 



Fam. c. Astartidse. Astarte, Crassatella, *Cardita. 



ORDER V. CYCLADACE^E. 



Fam. Cycladidse. Cyclas, Cyrena. 

 ORDER VI. VENERACE/E. 



Fam. Veneridae. Venus, Artemis. 

 ORDER VII. TELLINACE.E. 



Fam. a. Tellinidse. Tellina, Donax, Psammobia, Scrdbi- 



cularia. 

 Fam. b. Mactridse. Madra, Lutraria. 



ORDER VIII. MYACE^E. 



Fam. a. Myacidse. Mya, Corbula, Saxicava. 



Fam. &. Anatinidae. Anatina, Thracia, Pholadomya. 



Fam. c. Solenidse. Solen (Razor-shell), Cultellus. 



ORDER IX. PHOLADACE^E. 



Fam. a. Gastrochsenidee. Gastrochcena, Aspergillum. 

 Fam. b. Pholadidse. PJwlas, Teredo. 



The ordinal divisions in the above list cannot be regarded as in all 

 cases strictly natural groups, nor can they be considered as precisely equi- 

 valent to the " orders " of other classes of animals. 



