BIVALVES — CHAMA. 51 



Family 1. — With longitudinal ribsy gaping at the posterior slope. 



Scientijic Name, Locality. Common Name. 



Gigas Red Sea, Amboyna,China, 



New Holland Giant Clam 



Hippopus East Indies, Amboyna, 



China Spotted . . . do • • 



Family 2. — With longitudinal ribs, posterior slope closed. 



Antiquata Mediterranean, Gibraltar Antiquated do • • 



Ajar Mouth of the Niger, 



Tranquebar Ajar do • • 



Trapezia • • • • ' • • Norway- • • — Trapeziformdo • • 



*Rosca West Indies • Rose color'd do • • 



Calyculata East Indies, Mediterra- 

 nean, Senegal Variegated do • • 



Pectunculus Pectuncle • • do • • 



Satiata Obsolete- •• do •■ 



Rugosa Rugged - . • • do < • 



Family 3. — SJiell longitudinally ribbed, having an ovate chamber 

 in the interior of each valve. 



Concamerata - • • • Cape of Good Hope Chambered do • • 



Family 4. — Shell decussated or transversely striated, without ribs. 



Semiorbiculata • - Arabia Brown • • • - do • • 



Cordata -••• Ditto Heart-shap'ddo •■ 



Oblonga • • Guinea, Pulo Condore - • Oblong- • • • do - • 



Coralliophaga • • • East Indies, in coral • • • • Coral do • • 



Family 5. — Shell tuberculated. 



Plumbea South Seas Leaden"-«do 



E2 



