200 MOLLUSCA FROM THE CRAG. 
ANIMAL. 
This appears to be distinguished by its dental formula having no lateral teeth like 
those in Cypricardia. What has hitherto constituted the genus Venerupis, is a greater 
number of cardinal hinge teeth, being three in a parallel direction, whereas in this 
there are only two diverging widely from the umbo. It appears to be closely related 
to the Venus family, but at present little is known respecting the few species that have 
as yet been noticed. 
1. CoORALLIOPHAGA CYPRINOIDES. S. Wood. Tab. XV, fig. 7 a—d. 
CorALLIOPHAGA cypRINoIDES. S. Wood. Catal. of Crag Shells, in Ann. and Mag. of Nat. 
Hist., 1840, p. 250. 
Spec. Char. Testé ovato-oblongd, transversd, valde inequilaterali, nitida, levigata ; 
antice breviore, rotundatd ; posticé subtruncatd ; cardine bidentato divergente, sinu palliari 
minime profundo. 
Shell ovately oblong, transverse, very inequilateral, naked, smooth, closed ; 
anterior side the shorter, and rounded ; posterior somewhat truncate; hinge with two 
diverging teeth, and a small palleal sinus. 
Length, &ths of an inch; eight, 5 an inch. 
Localities. Cor. Crag, Ramsholt, and Sutton. 
This species does not appear to have been at all abundant. Var. a (fig. 4, c), found 
within the walls of a Balanus, represents the right valve, which is very elongated, thin, 
and fragile; this is particularly inequilateral, rounded on the anterior side, somewhat 
quadrate posteriorly ; the exterior is nearly smooth, or with merely irregular lines of 
growth, and itis rather more tumid on the posterior side, with a sort of obtuse diagonal 
ridge running from the umbo to the posterior part of the ventral margin; the hinge 
in this valve has a ledge or fulcrum for the ligament, within which is an elongated 
tooth nearly parallel, and behind the umbo, with a compressed one diverging under 
the anterior margin; in the left valve are also two teeth, one of which is of an obtusely 
triangular form, and seems to have been inserted between the two of the opposite 
valve, while the other fitted into the depression outside the anterior tooth of the right 
valve. Var. 3 (fig. a) is comparatively much shorter and thicker, and was found loose 
in the sand; the hinge area in this is broader and thicker ; the marks of the adductor 
muscles are large and somewhat deeply impressed, and that by the mantle has but a 
very small indentation; the length of the larger specimen is as one and a half to its 
height, whereas the smaller variety is scarcely longer than it is high. 
Venerupis striatula of Nyst, ‘Coq. Foss. de Belg.,’ p. 100, pl. iv, fig. 11a, 6, very 
much resembles our shell, but it has a large and deeply-indented sinus in the mantle- 
mark, and the shell to which he has referred his species has also the same dis- 
tinguishing character. 
