116 
twenty radiating rather convex ribs, which are some- 
what roughened by obsolete longitudinal and minute: 
transverse strize, and are narrower than their in- 
terstices; the color extremely variable, being yellow, 
white, pink, &c., but the lower valve always white.— 
Variety.P. Lrneatvs. Lam. 35.—Da. Cost. t. 10. f. 
8.—Mont. p. 47.—Pen. 4. p. 222.—Ostrea L. Lin. 
T. 8, p. 99.—Dor. Cat. p. 38.—D. p. 266.—The 
rays marked each with a longitudinal red line. 2. 
Very common. 
P.. Susrourus. Turt. B. p. 210. ¢. 17. f. L— 
OstrEA 8. Don. 1. ¢. 12:—Equivalve, suborbicular, 
equilateral and smooth, uniform rufous brown the 
twenty radiating ribs rounded and smooth. Torbay, 
A few transverse scaly marks towards the margin. 
P. Sinvosus. Pen. 4. p. 222. ¢. 64. ff 2.—F. p: 
384.—Lam. 49.—Turt. B. p. 210. @. 9. fi d.— 
Ostrea S. Gmel. 3319,—Lin. T. 8. p. 99.—Dor. 
Cat. p. 38. ¢. 10. f. 3,6.—D. p. 262.—Turt. D. p. 
130.—P. Distortus. Da Cos. p. 148. ¢. 10. f. 3,6.— 
Mont. p. 148.—P. Pusto. Don. 1.¢. 34.—Sow. G.— 
List. t. 172. f. 9.—Reeve. t. 114. f. 6.—Suborbicu- 
lar or longitudinally oval, inequivalve, variously dis- 
torted, white, pink or brownish, irregularly marbled or 
