Chama. MOLLUSCA. CHAMAD^. 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. canalictdata.^O\A(xig-ovdi\, flattish, plaited ; deeper valve with a la- 

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

 Sand. 



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

 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 

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



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



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



G. C. digitata — Palmate, slightly recurved, gibbose, with 5 or C marginal 

 elongated canaliculated processes ; surface smooth. — Sower. 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^. 



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. 1137. 

 Mmt. 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 d 2 



