230 MOLLUSCA FROM THE CRAG. 



5. Tellina Benedenii, Nyst and Westendorp. Tab. XXI, fig. 2, a — d. 



Tellina zonaria. Nyst, (not Lamk.) Rech. Coq. Foss. Prov. d'Anv., p. 14, 1836. 



Benedenii. Nyst et West. Nouv. Rech. Coq. Foss. d'Anv., p. 7, No. 13, pi. 2, 

 fig. 5 bis; pi. 3, fig. 5, 1839. 

 — — S. Wood. Catalogue, 1840. 



Spec. Char. Testa ovatd, subcequilaterali, cequivalvi, complanatd, laevigata, crassd ,- 

 antice rotundatd ; postice angidatd, sub acuminata, valvd altera dente cardinali duo ; 

 impressione palliari magno. 



Shell ovate, slightly inequilateral, equivalved, compressed, smooth, and thick ; 

 anterior side rounded ; posterior angulated, and somewhat pointed, two cardinal teeth 

 in each valve ; palleal sinus large. 



Length, 2 inches. Height, \\ inch. 



Locality. Red Crag, Sutton. 



My cabinet contains a single specimen of each valve, which are all that I have 

 seen. This species somewhat resembles T. pree tenuis, from which, however, it may 

 be readily distinguished. The umbo is somewhat prominent, it has a thickened 

 hinge furnished with two cardinal teeth in each valve, one small and simple, the 

 other bifid ; the simple one is posterior in the left valve, anterior in the right ; 

 besides which there is an obtuse lateral tooth on the anterior side of the left 

 valve, and a corresponding depression on the anterior dorsal slope in the right, for 

 its reception ; the adductor muscles are large and deep, and the sinus in the mantle 

 is of an elliptical form, extending about two thirds across the shell. 



The valves have a small and general convexity, and there is no tumid swelling 

 on the one side, or compression on the other, hence the similarity in the siphonal 

 scar; the surface is smooth (?), but may have been worn so; and there are traces of 

 the brownish coloured zones, which M. Nyst speaks of as ornamenting the Belgian 

 fossil. 



6. Tellina pr^etenuis, Leather MSS. Tab. XXI, fig. 5, a — c. 



Tellina PRiEXENUis {Leathes' MS.) Woodw. Synop. Tab. Brit. Organ. Rem., p. 11, 1830. 

 _ _ Woodw. Geol. of Norf., t. 2, fig. 12, 1832. 



Spec. Char. Testa ovato-trigond, incequilaterali, tenui, lavi ; antice majiore, rotundatd, 

 et conoexiusculd ; postice biangulatd, subrostratd, et compressd ; cardine bidentato ; dentibus 

 later ali bus nullis. 



Shell ovato-trigonal, inequilateral, thin, and smooth ; anterior side the larger, 

 rounded, and somewhat convex ; posterior biangulated, rather pointed, and com- 

 pressed ; hinge with two cardinal but no lateral teeth. 



Length, \\ inch. Height, \\ inch. 



