KELLIA. 93 



nearly elliptical, but rather abbreviated, the surface devoid 

 of all sculpture, and the ventral margin but little convex 

 in the middle, though arcuated at both extremities. The 

 sides are very nearly equal, and the dorsal edges, which 

 decline so slightly as almost to be parallel with the lower 

 margin, are nearly equally elevated, and each a little 

 convex. Both the front and hinder outlines are arcu- 

 ated and not angular, and the two extremities are nearly 

 equally broad. That which is rather the shorter, and 

 which, reasoning from analogy, we have termed the ante- 

 rior, is rather the more obtuse ; the scarcely longer pos- 

 terior side is, if anything, rather the more attenuated 

 above, from the more oblique uninterrupted arcuated 

 sweep of the dorsal margin. The beaks are distinct, but 

 not prominent, and scarcely lean to either side, yet if at 

 all to the shorter one. The hinge of both valves displays 

 a single narrow erect and obliquely slanting apical tooth 

 (which seems rather more conical in the right one), on 

 either side of which extends a distinct lateral lamina 

 (these are almost double in the left valve, but the upper 

 or outward set are very obscure), the front one shorter 

 and immediately adjacent, the hinder less approximate 

 and more produced. These lamina, which are in advance 

 of the hinge-margin, lean over it in the right valve, and, 

 especially in front, curl, as it were, outward. 



The extreme length of the largest specimens is scarcely 

 the sixth of an inch, and their breadth is rather less. 



The original locality of this species was Torbay, where a 

 few examples were procured from corallines by Dr. Turton. 

 Mr. Lyons (of Tenby) acquired his specimens from the 

 coral-sand of Ban try Bay, and a single broken valve (ap- 

 parently belonging to this species) was taken by Mr. 

 Jeffreys near the Island of Skye. Professor Macgillivray 



