60 
forating tooth in each valve, lateral teeth none: 
ligament extcrnal. 
A. Purpurea. Turt. B. p. 54. ¢. 4. f. 9.—Mya. 
P. Mont. Sup. p. 21.—Soxirn P. F. p. 459.—Oval, 
obliquely truncated anteriorly, convex, opaque, under 
a glossy white cuticle, chalky white, with irregular con- 
centric striz ; inside glossy white, hinge with a single 
conie tooth in each valve penetrating a corresponding 
cavity in the opposite. g...4. Torbay, in rocks. 
Genus.—_VENERUPIS. 
Transverse, inequilateral, posterior side short, the an- 
terior slightly gaping ; hinge with two cardinal teeth 
in the right valve and three in the left (sometimes 
three in each); teeth small approximated, parallel 
and slightly divergent : ligament external. 
V. Irvus. Lam. 3—F. p. 451-—Donax I. Lin. 
1[29.—D. p. 156.—Ch. f. 268,9.—Pen. 4. p. 100.— 
Mont. p. 108. and 573.— Don. 1. t. 29. f. 2.—Iin. T. 
8. p. 77.—Dor. Cat.p. 34. t.12. f. 6. (left-hand.)— 
Turt. C. D. p. 43.—Da. Cost. p. 204. t. 15. f. 6. 
(left-hand)—Pertricota I. Turt. B, p. 26. t. 2. f. 
14.—Oblong or oval, but variable in modifications 
being at times truncated and sometimes rounded, dull 
dirty white, with rather distant, thm, transverse, sub- 
reflected lamelle and regular close radiating strie in 
