Chama. MOLLUSCA. CHAMAD/E. 419 



CHAMAD^. 



Gen. CHAMA. — Beaks large, incurved, unequal; ligament 

 external ; hinge with one thick, oblique, subcrenated tooth 

 in one valve entering a pit in the opposite. 



1. C. haleotoidea. — Flattish, oval, uneven, with one longitudinal curved 

 line outside, and a deep curved hollow within the deepest valve, extending 

 from the beak around one side ; the remainder very shallow, margin thin, 

 broad, slightly fringed, crenate within ; muscular impression large. — Sower. 

 Min. Conch, t. xxv — Green Sand. 



2. C. canaliculata Oblong-oval, flattish, plaited ; deeper valve with a la- 

 teral canaliculated projection — Sower. Min. Conch, t. xxvi. f. 1. — Green 

 Sand. 



3. C. recurvata Deep valve conical, curved ; beak 'subinvolute — Sower. 



Min. Conch, t. xxvi. f. 2. — Green Sand. 



4. C. conica. — Oblong, curved ; larger valve deep, with a blunt conical 

 beak, and a small wing ; lesser valve oval, flat, with a crenated margin and 

 whiff. — Sower. Min. Conch, t. xxvi. f. 3 — In Green Sand. 



5. C. plicata Transversely ovate ; beak short ; deeper valve with a nar- 

 row channelled wing — Sower. Min. Conch, t. xxvi. f. 4 — Green Sand. 



0. C. digitata Palmate, slightly recurved, gibbose, with 5 or 6 marginal 



elongated canaliculated processes; surface smooth — Soiver. Min. Conch. 

 t. clxxiv Green Sand and Middle Oolite. 



7. C. squamosa. — Attached by the right valve ; nearly orbicular, subglo- 

 bose, imbricated ; lamellae undivided, somewhat erect, anteriorly produced, 

 and adpressed ; posterior part of the right valve obsoletely costated ; left 

 valve rather convex; smooth within. — (Brander, 86, 87-) Sower. Min. Conch. 

 t. cccxlviii. — London Clay. 



CARDIAD.E. 



Gen. CIX. ISOCARDIA.— Beaks distant, involuted, and 

 inclining forwards ; hinge with two flat oblique teeth at 

 the beak, and a remote lateral one under the ligament. 



—430. I. Cor. — Shell tumid, smooth, brown, with the beaks 

 clouded white. 



Bucardia, List. Conch, t. cclxxv. — Chama cor, Linn. Syst. i. 1 137- 

 Mont. Test. Brit. 134. Laskey, Wern. Mem. i. 385. t. viii. f. 7— I- 



cor. Turt. Biv. Brit. 193. t. xiv Found in deep water on different 



parts of the coast, burrowing in the mud. 

 Length approaching 4 inches, and nearly as broad. Mr Bulwer has point- 

 ed out some differences between the individuals found on the east coast of Ire- 



D(12 



