230 MOLLUSCA FROM THE CRAG. 
5. TELLINA BENEDENII, WVyst and Westendorp. Tab. XXI, fig. 2, a—d. 
TELLINA zonaRIA. Nyst, (not Lamk.) Rech. Coq. Foss. Proy. d’Anv., p. 14, 1836. 
— Beneprentt. Nyst et West. Nouv. Rech. Coq. Foss. d’Anv., p. 7, No. 13, pl. 2, 
fig. 5 bis; pl. 3, fig. 5, 1839. 
— — S. Wood. Catalogue, 1840. 
Spec. Char. Testé ovata, subequilaterali, equivalvi, complanatd, levigatd, crassd ; 
antice rotundatd ; postice angulatd, subacuminatd, valvd alterd dente cardinali duo ; 
ampressione palliart 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, 15 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 7. pretenuis, 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 PRETENUIs, Leathes’ MSS. Tab. XXI, fig. 5, a—e. 
TELLINA PRHTENUIS (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, inequilaterali, tenui, levi ; antice majiore, rotundata, 
et convexiusculd ; postice biangulatd, subrostratd, et compressa ; cardine 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, \% inch, Height, 1} inch. 
