101 



straight, without ribs at the extremities ; teeth nu- 

 merous, serrated, close-set, alternately inserted into 

 opposite valves ; ligament external. 



* Crenulated at the margin. 



A. NOJE. Lin. 1140. D.p. 226. Lam. 3. Ch.f. 

 529. Mont. p. 139. Pen. 4. p. 215. Lin. T. S.p. 

 91. Don. 5. 1. 158. /. 1,2. Turt. D.p. 9. /. 58. 

 Turt. B.p. 166. F.p.697. Oblong, decussated in 

 a punctured manner, pale rufous with darker oblique 

 bands, rounded posteriorly, anteriorly angular ; beaks 

 near one end, very remote, incurved, with a broad smooth 

 space between them ; ventral edge sinuous and gaping 

 in the middle ; inside whitish or pale chocolate brown. 

 i...f . Guernsey and W. Coasts. 



A. FUSCA. Don. 6. t. 158. /. 34. Mont. Sup. p. 

 51. t. 4. /. 3. Pen. 4. p. 215. Turt. D. p. 10. 

 Turt. B. p. 167. F. p. 397. IMBRICATA. D. p. 

 226. Ch. f. 532. List. t. 367. /. 207. Oblong, 

 uniform brownish white, decussated, angular anteriorly, 

 the ventral edge shorter, straight and nearly closed.- 

 W. Coasts. Resembling the last, but is proportionably 

 narrower, more convex, with finer decussations, the 

 margin nearly straight and the beaks very remote* 

 Hare. 



