34 BIVALVES __ MACTRA. 



tbrm, and has a small hollow on each side ; and though 

 it is very strongly articulated in some species, the teeth 

 are universally thin and fragile. The interior margin 

 is rarely crenated or toothed. 



The Mactra is derived from /jLaKT^a, a kneading 

 trough. 



Division I. — Shell sub-angular. 



Family 1. — Having a smooth surface. 



Scientijic Name. Locality. Common Name. 



Spengleri Cape of Good Hope • • • • Spengler's Mactra 



* Carinata Mediterranean Keeled • • • • do 



Maculata Nicobav Isles Spotted • • • do 



Corallina Mediterranean, Guinea- • Banded* • • • do 



Lactea Tranquebar Milky ..•• do 



* Cinerea Britain- .-i Ashy do 



Stultorum Britain Foolish do 



Grandis New Jersey Great do 



Achatina Agate do 



Triangularis Britain Triangular do 



Minutissima Minute • - - do 



Donacifonnis • • • • Ceylon Donax do 



Family 2. — Having a striated or wrinkled surface. 



Striatula W. Indies, Mediterranean Striated - • • do 



Plicataria Indian Ocean Plaited do 



Papyracea Nicobarlsles Paper •-•- do 



Vitrea Ceylon Brittle do 



Cygnea Tranquebar Swan do 



Turgida Ditto Inflated ••- do 



Violacea Ditto Violet • • - - do 



Cuneata Ditto Wedge- • • • do 



Rotundata Roundish • - do 



Glabrata African Ocean Smooth - • . do 



Nitida Delicate • • . do 



Striata Striated ••• do 



Radiata Britain • Rayed do 



