23 



bling the last species but is strongly striated radiatingly, 

 the lower valve from the lower anterior angle and the 

 superior one from the upper posterior angle, these are 

 crost by fine stride; the angles of the valves are much 

 more sharp and pointed and particularly the apex; the 

 dorsal valve is compressed at the sides and brought to 

 a fine carinated edge; bluish white; membrane and 

 peduncle orange red. Drifted wood, Devon, rare, 1. If. 



A. SULCATA. LEPAS S. Mont. p. M.t. I./. 6. 

 Lin. T. 8. p. 29. Dor. Cat. p. 26.Turt. D.p. 72. 

 Wood. G. C.p. 68. t. 12. /. I. D.p. 31. Com- 

 pressed, subtriangular, dirty yellowish white, shorter 

 than the last; lower valves with fifteen strong ribs 

 diverging from the lower anterior angle, that which runs 

 along the front is larger than the rest and forms a mar- 

 gin, the two superior valves form a pointed apex and 

 narrow downwards to a point ; furnished with seven or 

 eight ribs, with smaller intermediate ones diverging 

 from the posterior margin; dorsal valve somewhat 

 compressed, with a smooth subcarinated edge ; pedicle 

 short and dusky. -^. i. Dorset, rare. 



A. FASCICTJLARIS. LEPAS F. Ellis, Zoop, t. 16. f. 

 6. Mont. p. 557. and Sup. p. 5. and p. 163. 

 Lin. T. 8. p. 30.Turt. D .p. 72. Wood. G. C.p. 

 62. t. 10. / 4. D.p. 31. LEPAS DILATATA. Don. 

 t. 104. A. VITREA. Lam. 5. Compressed, with five 



