122 MOLLUSCA FROM THE CRAG. 



Spec. Char. Testa transversd, ovatd vel ellipticd ; valde incequildterali, convexd, 

 lavigatd, politd, tenui ; antice productd, utrinque rotundatd ; margine dorsali Jlexuosd ; 

 cardine valvuld sinistrd bidentato ; dentibus lateralibus nuttis. 



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, T \ths. Height, Jth 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 CYCLADIA, S. Wood. Tab. XI, fig. 4, a, b. 

 KELLIA CYCLADIA. S. Wood. Catalogue, 1840. 



J. Sowerby. Min. Conch., t. 637, fig. 6, a, 1844. 

 SCACCHIA OVATA? Phil. En. Moll. Sic., vol. ii, p. 27, t. 14, fig. 9, 1844. 



Spec. Char. Testa transversd, obliqud, tumidd, ovato-trapezoided, valde inaquilaterali, 

 tenui, fragili ; margine dorsali integerrimo ; antice 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. 



