APPENDIX. 365 



extreme squamiferous costae), which are very close-set ; the hinder 

 ones finely subnodulous. Ligamental edge rising, straightish ; ven- 

 tral edge arcuated behind, retuse in front ; ligamental area somewhat 

 sunken. -|. Isle of Annaa. 



Cardium orbita (t. 17, f. 17), Brod. and Sow. Z. P. 1833. — Sow. 

 C. I. Car. f. 13. — Reeve, I. Car. f. 85. Large, obliquely oval, gib- 

 bous, longitudinal, solid, variegated with fulvous stains on a whitish 

 ground, with about 42 radiating ribs ; front ribs armed with short 

 and very crowded oblique scaly tubercles ; hinder ribs with overlap- 

 ping plates, the arcuated extremities of which form, as it were, 

 concentric crenae, intervening ones laterally but unevenly serrato- 

 squamose or creno-serrated on each side, the front being invariably 

 the rougher side ; costal intervals deep, rather narrow, smooth to 

 the eye; inside white, edged with purplish red. 2£...3£. Isle of 

 Annaa. Even the central ribs become wholly squamose near the 

 ventral margin. 



Cardium incarnatum (t. 17, f. 27), Reeve, Z. P. 1844, p. 167 ; 

 I. Car. f. 2. Longitudinally suborbicular, subequilateral, thickish, 

 tumid, of an uniform glossy flesh-colour, which changes to pink near 

 the margin, radiated with about 26 prominent ribs, that are rounded 

 above, undercut at their bases, surmounted by a row of minute 

 spinous grains (often abraded), and are separated by much narrower 

 intervals, which are crossed by obsolete sulci; ventral edge much 

 arcuated ; umbones prominent, very oblique ; inside whitish, dirty 

 pink in front, strongly ribbed. If ...1^. Philippines. 



Cardium Deshayesii (t. 17, f. 34), Payr. t. 1, /. 33, 4, 5. — Sow. 

 C. I. Car. f. 70. — Reeve, I. Car. f. 83. Rotundately cordate, gib- 

 bous, pale rusty brown, nearly equilateral, with 22 radiating ribs, 

 which are armed down the middle with a row of short spoon-shaped 

 scales vaulting over tow r ards the umbones ; posterior scales wider, 

 and rather depressed ; intervals transversely marked with wrinkled 

 striae. If. Mediterranean. 



Cardium glaucum (t. 17, f. 36). — C. rusticum, Ch. (not Lin.) 

 f 197. — Desh. El. C. t. 25, /. 1.— C. a. Brug. E. p. 221.— 

 C. Lamarckii, and Belticum, Reeve, I. Car.f. 93, 113. — C. edule, 

 var. Br. Mol. Oboval, or ovate, transverse, thinnish, tumid, glossy, 

 subinequilateral, white tinged with bluish gray, usually smoke- 

 coloured in front, radiated with about 24 rounded ribs, of which the 

 posterior ones are set with raised concentric wrinkles that else- 

 where become wholly or partially obsolete. Hinge and internal 

 ribs brown. 1|...1£. Europe. I think it an extreme variety of 

 C. edule. 



Cardium Caspium (t. 17, f. 38). — Corbula C. Eichw. Zool. Spec. 

 — Monodacna C. Eichw. Faun. Gasp. — Car. C. Reeve, I. Car. 



