142 TESTACEOUS MOLLUSCA. 



truncated, flattish, and slightly keeled at its border, but becomes 

 elevated towards the margin of the valves : within quite white. 1£. 

 1.— W. Indies. 



C. Fragum. Lin. 1123.— D. p. 118.— Lam. 41.— Ch f. 

 1G6, 7.— E. t. 295. f. 3.— Wood. G. C. t. 58. /. 3.— W. *. 5. 

 f. 51. Somewhat heart-shaped, angulated and truncated ante- 

 riorly, yellowish white with about twenty-three rather depressed 

 longitudinal ribs armed with small crescent-shaped scales of the same 

 colour, towards the margin : within white with a pale orange 

 streak extending half way from the hinge to the margin. 1 \. . . 1 — 

 E. Indies. 



C. Retusum. Lin. 1121. — X>. p. Wl.—Lam. 42.— Ch. f. 

 139, 140, 1, 2.— E. t. 294./. 2, 3.— W. t. b.f. 52.— Heart-shaped, 

 white and shining, (or sometimes pale yellow and occasionally 

 spotted with red,) with about twenty-one longitudinal, crenated 

 grooves, whose intermediate ribs are more or less tuberculated ; 

 umbones carinated, with a crescent-shaped cavity beneath them 

 on the posterior side, within white. If. . li. — Persian Gulf 

 and lied Sea. 1 



C. Tumoriferum. Lam. 43. ~ C. I. f. 22. — Reeve, t. 77- f. 

 22. — Del. t. 11./. 7. Heart-shaped, inflated, whitish, subquadri- 

 lateral, one side obtusely rectangular, the whole of the broad 

 flattened ribs nearly smooth : In mile large and smooth. New 

 Holland. (3Iuch resembles the next, but the posterior depression 

 is not margined by mrinhles.) 



C. Hemicardium. Lin. 1121. — D.p. 113. — Lam. 44. — Ch. 

 f. 159, 160, ].—E. t.295.f. .2—W.t. 5. /. 49. Heart-shaped, 

 subtrilateral, whitish or pale yellow ; tumid and keeled at the 

 anterior end ; the anterior ribs smooth, the posterior tuberculated, 

 and the interstices narrow and marked with impressed dots ; the 

 lunule margined by coarse wrinkles. \\. . 1. — Molluccas. 



1 Mr. Sowerby in the Conch ological Illustration, considers the 

 C. Auricula of ForshaeVs Fauna Arabica, as distinct front this 

 species, although it has usually been considered by Dilwyn, Sfc. 

 as a variety differing chiefly by its coloured markings. I give the 

 description of an authenticated specimen. Subtrapeziform, diago- 

 nally divided by rather a sharp ridge, white spotted with pale 

 scarlet, with about twenty-one radiating ribs : posterior area slightly 

 larger, its ribs nodular and but little elevated, the interstices very 

 narrow and transversely crenulated: anterior ribs unarmed, narrower 

 and more depressed, with the interstices simple : lunule large, 

 deeply excavated, an internal broad cordiform callus, rendering the 

 cavity lunate. 1-J-. . . 1. ((?. /./. 47.)— lied Sea. 



