XXV1L. 
DIBRANCHIA. PSEUDOLAMELLIBRANCHIATA. 
Lucinacea. Ostreidze 
Lucinide. Aviculide, 
Tellinacea. Pectinide. 
Tellinide. Limide. 
Scrobiculariide, FILIBRANCHIATA. 
Anatinacea. Mytilide (ex. Dreissensia). 
Cuspidariide. Anomiide. 
Pandoride. Arcidee. 
Lyonsiide. PROTOBRANCHIATA. 
Anatinide. Nuculide. 
The order therefore adopted is :— 
Arecacea. 
Family Arcidee. 
Genus Area, L. 
Barbatia, Gray. 
Peetunculus, Lam. 
Limopsis, Sassi. 
Nuculacea. 
Family Nuculide. 
Genus Nucula, Lam. 
Leda, Schum. 
Ostracea. 
Family Ostieidee. 
Genus Ostrea, L. 
Family Anomiidae. 
Genus Anomia, L. 
