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. 



8. Wood. Catalogue, 1840. 



Spec. Char. Testa ovatd, subaquilaterali, cequivalvi, complanatd, Icevigatd, crassd ; 

 antice rotundatd ; postice angulatd, subacuminatd, valvd alterd 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, 1-| 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. prcetenuis, 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; arid there are traces of 

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

 fossil. 



6. TELLINA PR^ETENUIS, Leathes' MSS. Tab. XXI, fig. 5, a c. 



TELLINA PR^TENUIS (Leathei 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, Icsvi ; antice majiore, rotundatd^ 

 et convexiusculd ; postice biangulatd, subrostratd, etcompressd ; car dine bidentato ; dentibus 

 lateralibus 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, 1J inch. Height, \\ inch. 



