98 



t. II. f. l.Turt. B.p. 188. P.p. 422. Rounded- 

 heart-shaped, becoming obliquely heart-shaped from 

 the anterior side being produced by age, dirty white, 

 with about twenty-six ribs which are rough with trans- 

 verse wrinkled subimbricated striae ; inside white, 

 stained anteriorly with brown. li. The common 

 cockle. 



C. FASCIATUM. Mont. Sup. p. 30. . 27. /. 6. 

 Pen. 4. p. 191. Wood. G. C. p. 215. D. p. 130. 

 Turt. C. D.p. 32. Turt. B.p. 189. F. p. 422. 

 (the young of C . Rusticum. fide. Sow. in C. 1. Or- 

 bicular flattish, seuiitransparent, yellowish or pale 

 rufous, glossy, with a few dark transverse bands often 

 disposed in spots on the ribs. Not uncommon. 



* * * Rids unarmed. 



C. MEDIUM. Lin. UW.Lam. 40. Ch.f. 162, 

 3,4.^. t. 296./. I. Pen. 4. p. 186. Dow. 1. t. 

 32. /, I. Mont; p. S3. Lin. T. 8. p. 61. TTood. 

 G. C.p.2l\.t.5Q.f.3.D.p. U3.Turt.C.D.p. 

 32. Turt. B.p. 190. F. p. 422. Tumid, suborbi- 

 cular, rather truncated anteriorly, yellowish white, with 

 reddish brown blotches, about fifty radiating ribs which 

 are rather obscure in the middle but stronger at the 



