Donax. MOLLUSCA. DONACID.E. 433 



Mactra alba, Wood, Linn. Trans, vi. 174. t. xvi. f. 9-12. Ligula Boy- 

 sii, Mont. Test. Brit. 98. t. iii. f. 7 — Amphidesina Boysii, Turt. Biv. 

 Brit. 53. t. v. f. 4, 5 — Sandy shores, frequent. 

 Length half' an inch, breadth three-quarters, glossy, pellucid ; slopes from 

 the beak on both sides ; the ventral margin rather suddenly rounded; a sin- 

 gle umbonal denticle in each valve, and a large lateral tooth on each side in 

 one valve ; it is readily distinguished by its shortness and pellucidity. 



471. A. tenue. — Subtriangular, equilateral with a rounded 

 ventral margin. 



Ligula tennis, Mont. Test. Brit 572. t. xvii. f. 7-— A. tenue, Turt. Biv. 



Brit. 53.— South coast of England. 



Length a quarter of an inch, breadth a little more ; white, concentrically 



wrinkled, compressed, beaks produced, central ; hinge with one bifurcated 



tooth, and a remote lateral one in one valve, and a single plain tooth in the 



other. 



DONACIDiE. 



Gen. CXIX. DONAX.— Transversely subtriangular, retral- 

 ly short and truncated ; hinge with two teeth in both 

 valves ; lateral teeth rather remote. 



* Inner margin crenulated. 



-472. D. trunculus. — Shell with numerous minute simple 

 longitudinal striae, becoming obsolete towards the anteal extre- 

 mity. 



Tellina intus ex viola purpurascens, in ambitu serrata, List. An. Ang 



190; Conch, t. ccclxxvi. f. 217 — D. trull. Linn. Syst. i. 1127. Penn. 



Brit. Zool. iv. 93. t. Iv. Mont. Test. Brit. 103. Turt. Biv. Brit. 123. 



—Sandy shores, common. 

 Length five-eighths of an inch, breadth one inch and a quarter ; a yellow- 

 ish-white cuticle, inside purple, retrally obliquely truncated, the anal angle 

 rounded; anteally compressed, rounded, with the dorsal margin nearly 

 straight. 



473. D. denticulata. — Shell with numerous tine punctured 

 longitudinal striae. 



o 



Tellina purpurascens, List. Conch, t. ccclxxvi. f. 218. — D. dent. Linn. 

 Syst. i. 1127. Penn. Brit. Zool. iv. 93. Mont. Test. Brit. 104. Turt. 



Biv. Brit. 124 English shores, rare. 



Length about half an inch, breadth an inch ; whitish, rayed with purple. 

 It is more suddenly truncated retrally than the preceding species, and rough 

 with ridges. 



** Inner margin entire. 



474. D. complanata, — Transversely elongated, smooth, with 

 a longitudinal white band. 



vol. 1. e e 



