42 
margin; beaks central; hinge callus large, 
triangular. 
Syn. (Fossil). Thracia pubescens, S. V. Wood in 
Annals and Mag. Nat. Hist. v. 6 . 245. Morris, 
Cat. 102. 
(Recent) tab. DCXXXII. f. 4. Mya declivis. 
Pennant, Brit. Zool. iv. no. 15. Maton and 
Racket in Trans. Linn. Soc.v. viii. 36. Wood, 
Gen. Conch. 93. t. 18. /*. 2 $ 3. 
Mya pubescens, Pulteney in Hutchins's Dorset. 
27.t.4.f6. Montague, Test. Brit. 40. Turton, 
Conch. Diet. 99. Brit. Bivalves, 45. pi. 4 .f. 3. 
Thracia pubescens, Lam. Hist. Nat. 2nd ed. 
vol. 6. 83. 
In all the essential characters this crag fossil agrees with 
the recent shell of the western coast of England; if there 
be any difference the crag one is smoother and more truly 
oval, the ventral margin being more curved. 
Both the coralline at Ramsholt and the red crag at Sut- 
ton furnish this fragile shell ; it is also among the fossil 
shells of Sicily (Lamarck Hist. Nat. supra), and I have 
a young individual very closely resembling it. 
Some doubts having been formerly entertained of the 
identity of Pennant’s shell, which occurs in the Hebrides, 
with the Dorsetshire species, the name of the latter has 
been adopted, although declivis is the older, and ought in 
truth to be retained in preference. 
