48 
sides, pale brown with a few very obscure white rays ; 
beaks prominent, incurved, from which there is a de- 
pression to both extremities: inside pale with a tinge 
of blush. 1}...24. Weymouth. §c. 
M. Grauca. Gmel. 3260.—D. p. 144.—F. p. 428. 
—Mont. p.571.—Don. 4. t. 125. Pen. 4. p. 192.— 
Lin. T. §. p. 68.—Turt. B. p. 74.—M. HELvAcEa. 
Lam. 5.—Ch. f. 232.—M. Neavouitana. Poli. ¢. 18. 
f. 1, 2, 3.—Oval, flattish, inequilateral, faint irregular 
glaucous rays on a pale ground, finely striated trans- 
versely ; beaks recurved, with a narrow gape under them. 
22...3%. Very rare, Cornwall. 
M. Fraciuis: Turt. B. p. 74. t.4.f.10.—An Ch. 
f. 235.—F. p. 428.—Oval-oblong, compressed, nearly 
equilateral and smooth, pale yellowish white, transparent, 
angulated at the more produced side by arib which 
runs obliquely from the hinge to the margin; beaks 
pointed with a depression under them on the shorter 
side. 1}....2. Guernsey, very rare. 
Grenus.—LEPTON. Turton. 
Flat, nearly orbicular, equivalve, inequilateral, a little 
open at the sides, hinge of one valve with a single 
tooth and a transverse linear lateral one on each 
