122 MOLLUSCA FROM THE CRAG. 
Spec. Char. Testa transversd, ovatd vel ellipticé; valdé inequiliterali, convewd, 
levigatd, politd, tenut ; antice producta, utrinque rotundatd ; margine dorsali fleauosd ; 
cardine valvuld sinistra bidentato ; dentibus lateralibus nullis. 
Shell transverse, ovate or elliptical, convex; very inequilateral, smooth, glossy, and 
thin; anterior portion much the larger, and rounded at both extremities; dorsal 
margin sinuated ; hinge with two cardinal teeth in left valve ; no lateral teeth. 
Length, ;ths. Height, 3th of an inch. 
Locality. Coralline Crag, Sutton. Recent, Mediterranean. 
A large number of this pretty little shell have been obtained at the rich Depot 
of Molluscan remains at Sutton, where the two valves are occasionally, though 
rarely, found united. 
The most distinguishing mark of this species is the peculiar sinuosity of the upper 
margin of the shell on each side of the umbo in both valves, but that in the right one 
is the most conspicuous; a sinus or rather an indentation at a considerable, but about 
an equal distance both before and behind the umbo, received the edge of the margin 
of the left valve by which it is a little twisted, thus interlocking and serving the office 
of lateral teeth. The hinge is furnished with one obtuse tooth in the right valve with 
a deep depression immediately before it; in the left valve are two teeth, one of which 
is somewhat prominent and compressed, the other placed at right angles to it and in 
a line with the margin; these two, when the valves are closed, occupy a position on 
each side of the single tooth of the right valve. The ligamental area is small and 
oblique, sloping towards the posterior side; the muscular impressions are large and 
distinct, and the mantle mark without any inflection. 
I have not been able to compare my shell with the recent Mediterranean species, 
but from the peculiar character of a flexuous margin there cannot be much doubt of 
its identity ; my specimens do not appear quite so large as the one represented by 
Philippi. 
Scacchi’s name is restored upon the authority of M. Philippi. 
5. KELLIA cycLaptA, 8. Wood. Tab. XI, fig. 4, a, 6. 
Keita cycLtapiA. 8S. Wood. Catalogue, 1840. 
— -= J. Sowerby. Min. Conch., t. 637, fig. 6, a, 1844. 
Scaccuia ovata? Phil. En. Moll. Sic., vol. ii, p. 27, t. 14, fig. 9, 1844. 
Spec. Char. Testa transversd, obliqua, tumidd, ovato-trapezoided, valde inequilaterali, 
tenui, fragil ; margine dorsali integerrimo ; anticé majiore, postice subrecto ; dente cardinali 
unico, dentibus lateralibus nullis. 
Shell transverse, oblique, tumid, of an ovate trapezoidal outline ; very inequilateral, 
thin and fragile; dorsal margin without any inflection; anterior side the larger, 
posterior nearly straight ; one cardinal tooth and no lateral teeth. 
Length, + of an inch nearly. 
Locality. Coralline Crag, Sutton. Recent, Mediterranean. 
