Ilifiges of Britijh Bivalve Shells. 1 57 



Tab. XIV. Fig. i, 2. 



A thick, broad, upright, ftriated tooth in the upper 

 vahe*; in the lower valve, a deep, fpoon-fliaped 

 hollow, with a fmall tooth on one fide, and a fharp 

 ridge on the other, running from the beak towards 

 the truncated end. 



Lifter, in his Hi/Ioria Inimalium A glia, has figured the 

 lower valve of this ihell, but has totally miltakcn 

 the form of the tooth. 



Da Cofta, in his Britijh Conchology, and llkewife in 

 his Elements, has fucceeded better, although his 

 figures are by no nteans perfeft. 



arenaria, Linn. Syji. Nat. ed. GmeL i . p. 3218. Penn. Br. Zool. 

 No, 16. /. 42. /. 16. Z,//?. Conch, t, 418. /. 262. — 

 Ba^. Opufc. fubj. t, p. 69. /. T- /• 2, 3. Argenv. 

 Zoom. t. 5. /. 10. . 



Tab. XIV. Fig. 3, 4. 



Hinge with an upright, fanftiaped tooth ; on the fide, 

 a ridge deeply iulcated ; lower valve like the preced- 

 ing, except the fide tooth, which is fcarcely to be 

 diftinguifhed. 



Mr. Pennant has given a very good figure of the tooth 

 in the upper val\e of this ihell, and of the 

 M. truncata. 



* For the fake of perfpicuity, in the dcfcription of the Hinge, I have called that the 

 upper valve which contains the great tooth. 



inarg^iritijera. 



