COKCUYUk-^DITHYRA. 41. 187 



anterior side, with 20 tubercled ribs, the grooves between which 

 are striate transversely. 

 ' Cardium exiguum. GmeIin,Syst. p. 3255. 



Montagu, Test. Brit. p. 82. 

 Pennant, Brit. Zool. iv. p. 186. 

 Linn. Trans, viii.p. 61. 

 Iwr/on, British Fauna, p. 153. 

 Dorset Catal. p. 31, tab. 2, Hg. II. 

 Wood, Conch, p. 212. 

 Dillwyn, Descript. Catal. p. 114. 

 Turton, Conch. Diet. p. 31. 

 ' Cardium pygniaeum. Donovan, i. tab. 32, fig. 3. 

 Tnrtnn, Linn. Syst. iv. p. 207. 

 Cardium subcordatum. Walker, Test. Minut. p. 23, fig. 83 

 Cardium muricatum. Walker, fig. 84. 

 Pectunculus exiguus. Lister, Conch, tab. 317. fig. 154. 

 Mus. nasi. Western coasts and Ireland ; sometimes imbeddeii 

 in hard clay : and both Mrs. Griffiths and ourselves have taken 

 them from the interior of the hardest stone in Torbay. 



Shell about half an inch in diameter, whitish witli sometimes a 

 rosy tinge, triangular and produced at the anterior side, wifii 

 -from 20 to 22 ribs clothed with rounded obtuse tubercles, espe- 

 cially about the shorter side, the grooves of which are not always 

 very distinct, but towards tlie hinge transversely striate : insidt? 

 often rosy, with one of the teeth minute. 



^^ costis transversim squamosis. 



the ribs armed with transverse scales. 



2b 2 



