79 



or yellowish ray ; somewhat violet within, hinge with 

 two teeth in each valve, and a single lateral one. I ... 1 \. 

 Torbay and Guernsey. 



D. RUBRA. Mont. Sup. p. 38. Turt. C, D. p. 43. 

 Turt. B.p. 127. t. 10. /. 14. F.p. 435. Wedge- 

 shaped, smooth, uniform pale claret color, posterior 

 edge greatly sloping to an attenuated but rounded ex- 

 tremity, glossy, semi-transparent ; beaks prominent, 

 posterior ; a single approximate lateral tooth in eaeh 

 valve. &. Tenby. 



GENUS. CRASSINA. 



Suborbicular , transverse, equivalve, subinequilateral, 

 close ; hinge with two strong diverging cardinal 

 teeth in the right valve, and two unequal ones in the 

 other ; ligament external, broader than long. 



* Margin quite entire. 



C. SCOTICA. Turt. B.p. 130. t. ll./. 3,4. VENUS 

 S. Mont. Sup. p. U.Lin. T. 8. p. 81. t. 2./ 3. 

 Pen. 4. p. 204. D. p. 267. Turt. C. D. p. 236. 

 ASTARTE S. F.p. 440. Rounded-heart-shaped, rather 

 flat, white, under an olive or chesnut cuticle, very 



