276 MOLLUSCA FROM THE CRAG. 



mitted from the Older Tertiaries. M. Deshayes says the Paris Basin shell is un- 

 doubtedly identical with the Touraine species ; the latter corresponds more closely 

 with the Crag fossil ; the Kleyn Spauwen shell resembles more (as might be supposed) 

 the Paris Basin variety. The Touraine specimens differ slightly from the Crag fossil, 

 but not, I think, sufficiently to invalidate their identity. In our shell the siphonal 

 side is not so pointed or keeled, and there is a little difference in the dental furniture, 

 and the palleal sinus is a trifle larger. 



The ligament is placed in a fossette in the right valve, visible externally, when the 

 valves are closed, through a sinus in the umbo ; the left valve has a projection on 

 which are placed both ligament and cartilage, separated by a ridge : before this 

 ligament is a tooth in each valve. This w r as probably an estuary shell. The locality 

 (Roydon), given for it in ' Min. Conch.,' is an error. 



Sphenia Binghami ? Turton. Tab. XXIX, fig. 7. 



Sphenia Binghami. Turt. Brit. Biv., p. 36, t. 3, figs. 4, 5 ; and t. 19, fig. 3, 1822. 

 Sphlenia Binghami. Forb. and Hani. Hist. Brit. Moll., vol. i, p. 190, pi. 9, figs. 1 — 3, 



1848. 

 Cokbula Binghami. Hartley. Recent Shells, p. 47; Supp., pi. 12, fig. 4. 

 — — Woodw. Man. of Moll., vol. ii, p. 318. 



Spec. Char. Testa minutd, transversa, cuneiformi tenui fragili, laevigata, valde 

 incequilaterali ; antice roiundald, postice angnstd, subrostratd. 



Shell small, transverse, wedge-shaped, thin and fragile, smooth, and very inequi- 

 lateral ; anterior side rounded ; posterior produced and somewhat pointed. 



Length, \ inch. 



Locality. Cor. Crag, Sutton. Recent, Britain ? 



The genus Sphenia has been founded upon a single species of Mollusc inhabiting 

 our own shores, and is at present not well established : the animal has been examined 

 by Mr. Clark who says it is quite distinct from Mya or Saxicava, though not far removed 

 from either; perhaps still nearer to Corbula. 



Only two or three specimens, and those not in very good condition, are in my 

 Cabinet ; they will not throw any light upon the obscurity which hangs over the 

 recent shell. 



My best specimen has a spatulate tooth in the left valve, like that in the young of 

 Mya, which it resembles in some characters, but it is much thinner, with something of 

 a nacreous appearance ; and the outline also is different from that of the young of Mya 

 of the same size : mine is, however, a very doubtful identity of the existing species. 



