67 
170,—F.. p. 485.—Ovate, thin, transparent, glossy, 
white; anteriorly contracted, posteriorly rounded ; one 
of the valves obliquely striated, the other quite smooth 5 
two cardinal and asingle lateral tooth in one valve, only 
single cardinal in the other. %...¢. Common on sandy 
coasts. 
T. Simiuis. Sow. Brit. Mis. t. 75.—Mont Ap. p. 
187.—Turt. C. D. p. 170.—Turt. B. p. 102.—F. p. 
435.—Oval, with both valves obliquely striated; a 
lateral tooth in each valve. Paignton sands, very 
rare. 
T. Donacina, Lin. 1118.—D. p. 89.—Lam. 27.— 
Mont. p. 58. ¢. 27. f. 3.— Poli. 1. t. 15. f. 10.— Pen. 
4. p. 178.—Lin. T. 8. p. 50. ¢. 1. f. 7.—Dor. Cat. p. 
29. ¢. 12. f. 38n.— Wood. G. C. p. 161. é. 45. fi 5.— 
Turt. D. p.170.—F. p. 435.—Turt. B. t. 8. f. 4. p. 
103.—Oval-oblong, aiiteriorly very short and obtusely 
cuneifor 1. posteriorly rounded; the posterior dorsal 
edge but little slopiug 5 yellowish with narrow red, often 
interrupted rays, semi pellucid ; hinge in one valve with 
a cloven cardinal tooth, an additional simple one and 
lateral teeth on each side in the other. %...1.  Guern- 
sey, Devon, Dorset, not common, 
