25 



valves thirteen, those on the dorsal valve in transverse 

 rows, the three lower valves on each side to which the 

 peduncle is fixed, are very small, the two next larger, 

 the superior one the larges;, running a little oblique 

 to the rest, and is pointed at the top ; the dorsal valve 

 is compressed, the edge rounded at the base, and run- 

 ning into a sharp process about half-way up, from 

 whence it turns in a diagonal line to cover the edge of 

 the two superior valves : the upper part truncated ob- 

 liquely to the front. Sandwich and Plymouth, rare. 



P. CORNUCOPIA. Leach. Lam. 1. Reeve, t. 14. 

 /. 1. PENTALEPAS P. Bl. t. 84. /. 3. LEPAS. POL- 

 LICIPES. Gmel. 3213. Ch.f. 851. Z.Arg. t. 26. /. 

 D.Wood. G. C.p. 60. t. 10, /. 2. Knorr. 5. t. 

 13./. l.D.p. 29. Mont. Sup. p. 6. t. 28. / 5. 

 TurtD.p.74. Compressed, erect, solid, eight prin- 

 cipal smooth convex white valves, besides numerous 

 irregular small ones environing the base : four larger 

 valves obtusely pointed above ; membrane dark ; pedi- 

 cle coriaceous, bluish asVcolored and shagreened. 

 0,80. without the pedicle. Rather doubtful, very rare. 



GENUS CINE HAS. 



Body pedunculate, entirely enveloped in a thick mem- 

 branaceous integument, with a large anterior opening 



