f. 5. Obliquely heart-shaped, thick, ponderous, white, 

 under a coarse brown rather glossy cuticle, aud striated 

 irregularly and concentrically ; beaks pointed, no 

 lunule; inside dull white, margin vary entire. 4. 

 Open Coasts. 



* C. TRIANGULARIS. Turt. B.p. 136. t. 11. /. 19, 

 20. F. p. 444. VENUS T. Mont. p. 577. 1. 17. f. 3. 

 Lin. T. S.p S3. Pen. 4. p. 205. D. p. 173. 

 Turt. C. D. p. 238. Somewhat triangular, being 

 roundish, with a triangular outline towards the beaks 

 which are produced and equally sloping on both sides, 

 smooth, strong; lunule lanceolate; two teeth and a 

 curved lateral in one valve, three and a lateral in the 

 other, i. W. Coasts and Dublin Bay. 



C. MINIMA. Turt. B.p. 137. F.p. 444. VENUS 

 M. Mont. p. 121. t. 3. /. 3. Lin. T. 8. p. 81. Pen 

 4.p.2Q3.D.p. 166. Turt. C.D.p. 236. Rounded 

 heart-shaped, a little compressed, with broad smooth 

 transverse rather obscure ribs, whitish or flesh color, with 

 four red spots, two near the hinge, two at the margin, 

 and generally two white lines connecting the two upper 



This and the succeeding species are but provisionally 

 considered as of this Genus, 



