72 



white or yellowish ; beaks pointed, prominent and 

 curved, lunule small and cordiform ; inside polished 

 round the area of the margin ; in one valve a single 

 plain tooth closing between two plain ones in the other; 

 internal cavity oblique. I. Torbay and British 

 Channel. 



L. LEUCOMA. Turt. B. p. 113. t. l.f. 8. LORIPES 

 L. F. p. 430. Orbicular, rather oblique and inequi- 

 lateral, anteriorly a little produced and angular, arid 

 generally a little flexuous under the beaks posteriorly ; 

 convex, chalky white, marked with regular crowded 

 transverse raised striae and deeper wrinkles (sometimes 

 crossed by extremely fine and close set radiating lines) ; 

 beaks prominent with a curvature under them ; inside 

 and hinge as in Lactea. f . Torbay, British Chan- 

 nel and Guernsey. 



L. ALBA. Turt. B. p. 114. t. l.f. 6,7. Orbicular, 

 convex, glossy white, with rather remote regular trans- 

 verse striae ; hinge with two teeth in one valve, one in 

 the other ; internal cavity nearly in a straight line, f . 

 British Channel and Guernsey. More rounded than 

 the last and with no appearance of longitudi- 

 nal lines. 



