43 
Pubescens by the large oval projecting teeth, which 
extend forwards and have no lateral attachment. 
A. Pretenuis. Turt. B. p. 48. ¢. 4. f. 4.—Mya. 
P.Pen. 4. p. 160. ¢. 50. f. 1.—Mont. p. 41.—Lin. t. 
8. p. 37.—Don. t. 176.—Wood. G.C. p. 94. t. 24. f. 
7, 8, 9—Dor. C. t. 4. f.7.—Turt. C. D. p. 101.— 
Ampuipesma. P. F. p. 452.—Oval, flat, narrower 
rounded and open anteriorly, posteriorly slightly 
shorter and rounded, rough, white; teeth oval and pro- 
jecting. 1. ..12. Torbay. Distinguished from Declvisi 
by the rounded anterior extremity. 
A. Distorta. Turt. B. p. 48. t. 4. f. 5.—-Mya. 
D. Mont. p. 42. ¢. 1. f. 1.—Pen. 4. p. 161.—Lin. T. 
8. p..37.— Wood. G. C. p. 98.—D. p. 45.—Turt. C. 
D. p. 101.—Ampuipesma. D. F. p. 432.—Convex, 
variously shaped, nearly closed, the margin generally 
indented and the teeth rounded and projecting inwards. 
1. Torbay. 
A. Arctica. Turt. B. p. 49. t. 4. f. 7, 8.—Mya. 
Arctica. Lin.*1113 ?—Oblong, convex, posteriorly 
truncated, anteriorly with two transverse ridges, one 
along the back margin, the other running obliquely to 
the angle of the front margin; beaks terminal, posterior, 
