81 



Turt. C. D. p, 235. V. DANMONIA. Mont. sup. p. 

 45. t. 29. f. 4.D.p. 167. CRAS. SUL. Turt. B.p. 

 131. t. l\.f. 1,2. ARTARTE S. & D. F. p. 439. 

 Rounded heart-shaped, rather compressed, white under 

 a dark brown cuticle, with smooth, strong, regular, equi- 

 distant, transverse ridges; beaks subcentral, and in- 

 clining; limule subcordiform, lozenge lanceolate. 

 1 . . . 1 i . D evon and Ireland. 



TRIBE. CONCHACEA. 



With at least three cardinal teeth in one valve, usually 

 but not always the same in the other. 



GENUS. CYPRINA. 



Equivalve, inequilateral, obliquely heart-shaped, beaks 

 obliquely bent; hinge with three unequal teeth, 

 approximate at the base and slightly divergent 

 above ; lateral tooth remote (sometimes obsolete) ; 

 ligament external and partly sunk between the 

 beaks. 



C. ISLANDICA. Lam. 2. Turt. B. p. 135. F. p. 

 443. jBZ. t. 70. bis.f. 5. Sow. G. Reeve, t. 65. 

 VENUS T.Lin 1131. D. p. 176. List. t. 271. /. 

 108. Ch.f. 341. Pen. 4. p. 205. t. 56. Mont, p, 

 114. Don. t. 77. -Lin. T 8. p. S3. Dor. Cat. p. 

 35. /. 6./ 5. Turt, C. D.p. 238. Da Cost. t. 14, 

 D 3 



