122 MOLLUSC A FROM THE CRAG. 



Spec. Char. 2esfd transversa, ovatd vel ellipticd ; valde incBquildterali , convexd, 

 IcBvigutd, politd, temii ; antice product a, utrinque rotundatd ; mart/ine dorsali fexuoad ; 

 cardine valvuld sinistra bidentato ; deiitibus lateralihus 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. 



Lctiijfh, -i'^t\\^- Ih'iffht, ^th 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 tlie 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 comjiressed, the other placed at right angles to it and in 

 a line with tlie 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 lie 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. Kelli.\ cycladia, S. Wood. Tab. XL fig. 4, a, h. 



KiiLLiA CYCLADIA. S. Wood. Catalogue, lM-10. 



— —J. Sowerby. Min. Conch., t. 637, Cg. C, a, lS-1-1. 



ScACCHiA OVATA? Phil. Eu. Moll. Sic, vol. ii, p. 27, t. 1-1, fig. 9, IS-ll. 



Spec. Char. Testa transversa, obliqud, tumidd, ovato-trapezoided, valde inaquilateraii, 

 tenui, frayili ; margine dorsali intcfferrimo ; antice majiore, postice subrecto ; dente cardinali 

 unico, dentibus lateralihus nullis. 



Shell transverse, oblique, tumid, of an ovale trapezoidal outline ; very inetjuilateral, 

 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. 



Localiti). Coralline Crag, Sutton. Recent, Mediterranean. 



