CRASSATELLA. 485 



Species of Gould hi. 



cerina, C. B. Adams. Pacifica, C. B. Adams. 



Guadaloupensis, D'Orb. parva, C. B. Adams. 



Martiuicensis, D'Orb. varians, Cpr. 

 minima, Mont. 



Genus CRASSATELLA, Lamarck. 



Shell solid, closed, equivalve, attenuated behind ; surface 

 of valves smooth, or furrowed concentrically; margins 

 simple, or crenulated; lunule distinct. Hinge composed of 

 two sub -diverging, striated primary teeth placed in front of 

 a cartilage-pit ; lateral teeth usually one in each valve ; 

 ligament internal, inserted in a pit in each valve. Muscular 

 impressions strong, rounded; pallial line simple. 



Syn. Ptychomya, Agassiz (fossil). Paphia, Roissy, not 

 Lam. or Fabr. 



Ex. C. pulchra, Reeve, pi. 116, fig. 1. Shell, C. 

 Kingicola, Lamarck, fig. 1, a, 1, b. 



In this genus the mantle is entirely open, with the in- 

 halent margins cirrhated ; the palpi are triangular ; and the 

 foot is compressed, triangular, and grooved. The species 

 are usually dredged from deep water, and are most nu- 

 merous in the Australian Seas; four, however, have been 

 obtained from Asia, three from America, and one from 

 Africa; while none have hitherto been detected in Europe. 

 The genus is found in a fossil state in the Neocomian of 

 Patagonia and the South of Europe. 



VOL. II. 3 R 



