124 MOLLUSC A FROM THE CRAG. 



In dental characters and position of the ligament it corresponds with some of the 

 other species included in this genus, and appears to be more closely allied to it, than 

 to Galeomma in which Philippi has placed his shell, which is considered here with 

 doubt as an identity. 



One specimen of mine has the two valves united, but does not show an opening 

 at the ventral margin, a character essential to that genus ; there is a twist in the 

 shell, and the single valve, when laid with its margin downwards, will not touch on all 

 sides, and this bend in the opposite valve is in the contrary direction, so as to bring 

 the margins of the two pieces together at all parts when the valves are closed ; never- 

 theless there is something about it peculiar to itself as possibly not to belong to either 

 this or to Galeomma. 



7. KELLIA PUMILA, S. Wood. Tab. XII, fig. 1 5, a, b. 



MONTACUTA PUMILA. <S. Wood. Catalogue, 1840. 



KELLIA PUMILA. J. Sowerby. Min. Conch., t. 637, fig. 3, 184G. 



Testa minima transversd, ovatd, obliqud, tumidd, valde inaqmlaterali, Itjemgatd, politd; 

 antice majiore et longiore, utrinque rotundatd; dente cardinali unico, dentibus later alibus 

 magnis. 



Shell small, transverse, ovate, oblique, tumid, very inequilateral, smooth, and 

 glossy ; anterior side much the larger and longer, both sides rounded ; hinge with 

 one cardinal tooth, and two lateral teeth. 



Diameter, T Vt;h of an inch. 



Locality. Cor. Crag, Sutton. 



This is a very abundant shell at the above locality, where the two valves are 

 often found united, their large and prominent teeth having kept them in their natural 

 position. 



Without allowing a latitude in variation beyond what we are accustomed to do, 

 even with such variable species as were the inhabitants of the Crag Seas, this shell 

 can scarcely be admitted as an identity with the K. rubra, although it bears a close 

 approximation ; and as the Malacologists have placed the recent shell in Kellia, it is 

 thought best to follow their example, although it does not strictly accord in its dental 

 characters with the diagnosis of that Genus. 



Our shell is more inequilateral than K. rubra, and the hinge is quite at the side, 

 the umbo being almost terminal, and the posterior lateral tooth then forms nearly a 

 right angle with the beak and anterior lateral tooth : in the recent shell the hinge 

 is much more central, with less of gloss upon the exterior ; ours was perhaps a more 

 transparent shell, with the teeth rather less distinct: thus differing more from the 

 Mediterranean shell, according to Messrs. Forbes and Hanley, than from the British ; 

 there are two prominent lateral teeth, with a central one in the right valve, and 

 two smaller nearly obsolete lateral teeth in the left valve. 



