364 TESTACEOUS MOLLUSCA. 



C. Mortoni, p. 140, t. 16, f. 50, 51 ... C. fragile, p. 141, t. 17, f. 51 

 ... C. lyratum, p. 141, t. 17, f. 1 ... C. tumoriferum, p. 141, t. 17, 

 f. 50 ... C. monstrosum, p. 143, t. 17, f. 32 ... C. lineatum, p. 143, 

 t. 16, f. 53 ... C. imbricatutm, p. 143, t. 17, f. 42 ... C.fornicatum, 

 p. 143, t. 17, f. 49 ... C. biangulatum, p. 143, 1. 17, f. 19 ... C. plani- 

 costatum, p. 144, t. 17, f. 48 ... C. subretusum, p. 144, t. 17, f. 29. 



Cardium lacunosum (t. 16, f. 52), Reeve, Z. P. 1845 ; I. Car. 

 f. 81. Ovate or elongated-ovate, usually somewhat oblique, subequi- 

 lateral, thick, tumid, ochraceous-yellow, usually paler in the umbonal 

 region, spotted and sometimes banded with livid red, radiated with 

 from 30 to 34 narrow prominent ribs, whose sides are more or less 

 concave, and whose wrinkled intervals in front are broader above than 

 below. Central ribs crenated or serrato-crenated on each side, extreme 

 front ribs with oblique compressed scaly tubercles ; hinder ribs closely 

 set with flattened scaly plates, the rounded tops of which imbricate 

 each other upwards (in the direction of the umbones). Ventral edge 

 peculiarly arcuated, stained inside with crimson in front ; lunular site 

 brownish lake ; beaks scarcely inclined ; inside white, with 2 shortish 

 umbonal rosy rays. 2. Zanzibar. 1 lie flattened summit of the ribs 

 forms a protruding ledge. 



Cardium rubicundum (t. 16, f. 54), Reeve, Z. P. 1844, p. 169 ; 

 I. Car.f. 144. Like C. lacunosum, yet scarcely so tumid, the ground- 

 colour rosy, speckled with orange-brown, and variegated with white, 

 with 37 ribs, whose intervals are narrower, the scales on the anterior 

 ribs sharper, and not restricted ventrally to the extreme costse. 2. 

 Zanzibar. The internal rays less distinct and often ochraceous. 



Cardium obovale (t. 17, f. 10), Sow. Z. P. 1833, p. 84. — Sow. 

 C. I. Car. f 4. — Reeve, I. Car. f 117. Peculiarly oblique, peaked 

 oval, longer than broad, rounded at both ends, solid, tumid, wholly 

 white, with about 21 radiating ribs, of which the 7 front ones are 

 smooth depressed and divided by narrow intervals, the next 3 larger 

 prominent and regularly crenated by closely-disposed subarcuated 

 concentric raised lines, the remainder less elevated, broader than their 

 intervals, and smooth, except their front edges, which are serrato- 

 crenated ; the costal interstices very finely and closely cancellated 

 concentrically ; no umbonal ridge ; umbones almost terminal ; no de- 

 fined lunule. f...^. W.Columbia. 



Cardium Dioisleum (t. 17, f. 11), Soiv. Z. J. 4, p. 367 ; Beech. Z. 

 t. 42, /. 6.— Sow. C. I. Car. f 52.— Reeve, I. Car. f. 122. SmaU, 

 subrhombic, very inequilateral, white, radiatingly ribbed, with a 

 remotely spinous carinated angle running very obliquely from the 

 beaks to the peaked and projecting anterior extremity. Valves tumid 

 at the keel, laterally compressed, broadly biangulated in front, rounded 

 behind. Ribs depressed, especially the front ones (except the two 



