103 
F, p. 398.—A. Perrorans. Turt. D. p. 9.—Turt. 
B. p. 169. t. 13. f. 2,3.—Oblong, subequilateral, 
rounded posteriorly and angular anteriorly, white with 
a brown velvety epidermis, and crowded longitudinal 
riblets which are merely crossed by the striee of growth 5 
beaks distant, the ligamental area black oblong and 
sunken; inside white, ventral edge but slightly open, 
+...4. W. Coasts, in rocks. 
GEenus.—PECTUNCULUS. 
Suborbicular, double convex, equivalve, subequilateral 
and closed; hinge arcuated, teeth numerous, oblique, 
serrated; ligament external. 
P. Giycimeris. Deshayes.—P. GiycimMeEris, UN- 
patus & Pirosus. Turt. B. p. 171. €. 12. f. 1, 2,3, 4. 
—P. P. & P. Marmoratvus. Lam.—P. Pivosus. 
Phillippi.—F. p. 400.—Arca. G. Lin. Mus. Ulric.— 
A. Pixosus. D. p. 242.—A. Marmorata. Gmel. 
3314.—Ch. f. 560. §& 563.—List. t. 247. f. 82.— 
Knorr. 6. t. 14. f. 4.—Gual. t. 72. f. 6.—E. t. 310. 
Jj. 3.—A. GrycrmerRis. Pen. 4. p. 216.—Lin. T. 8. p. 
93. t. 3. f. 3.—Turt. D. p. 7.—Orbicular-ovate, be- 
coming inequilateral by age, white with angular red 
streaks arranged either longitudinally or transversely 
{sometimes flesh-coloured with white spots and angular 
red ones), minutely decussated, the apices obliquely 
