97 



about twenty-six close-set rounded ribs, thickly clothed 

 with obtuse round tubercles, which anteriorly project 

 into very short spines ; beaks central, inside white with 

 generally a chesnut anterior stripe reaching half-way 

 down the shell ; margin strongly serrate, i. Torbay. 

 The old shells in this and the succeeding species lose 

 the tubercles and become wrinkled or scaly all over. 



C. EXIGUUM. Gmel. 3255. Mont. p. 82. Turt. 

 B.p. 187. Pera. 4. p. 186. Lin. T. 8. p. 61. 

 Wood. G. C.p.2\2.Turt. D.p.Zl.-F.p. 422. 

 Dor. Cat. p. 31. t. 2. /. ll.D.p. 114. C. Pra- 

 M^SUM. Don. t. 32. f. 3. Subtriangular, tumid, sub- 

 truncated anteriorly, whitish, rarely pink, with from 

 twenty to twenty-four ribs clothed with rounded obtuse 

 tubercles especially about the shorter side, the grooves 

 of which are not always distinct, but towards the hinge 

 transversely striated ; inside often rosy, one of the teeth 

 minute, i. W. Coasts and Ireland. 



* * Ribs armed with transverse scales. 



C. EDULE. Lin. 1124. D. p. 127. Lam. 31. 

 Ch.f. 194. Pen. 4. p. 189. t. 53. /. 3. Mont. p. 

 76. Dor. Cat. p. 32. t. 11. /. \.-Wood. G. C. p. 

 226. t. 55. /. 1. Turt. C. D.p. 30. Da Cos.p. 180. 



