LIMA gibbosa. 
TAB. CLII. 
Spec. Char. Elongated, gibbose, smooth, longi- 
tudinally plicated in the middle ; ears undefined. 
Syn. Lister 495. ? 
Walcot f. 22. ? 
rS early twice as long as wide, slightly oblique, in the 
middle about 18 small sharp plaits without any scales or 
even roughness. The ears are hardly worthy of that 
name as they are only expansions of the sides from the 
ends of the hinge line: the depth is greatest near the com- 
mencement of the beaks, where it almost equals the 
width. 1 have some doubts about the propriety of calling 
this a Lima; the form of the hinge corresponds, but the 
want or imperfection of the ears and the valves not gaping 
are objections ; there are, however, some recent species 
of the Genus, which nearly resemble it in these parti- 
culars. 
Cotswold hills, Gloucestershire, and Taunton afforded 
this to Mr. Richard Taylor, jun. with a small Isocardia 
of Lam. and other shells in coarse Limestone with 
granulae like the small Oolite of Bath, &c. and I believe 
the species has been found near Bath, but has not been 
understood: I presume it will soon be better known. 
Some of this Genus, at first sight, appear like Pla- 
giostoma, but by careful examination may be distin- 
guished by the thickness of the shell in the hinge, and the 
presence of the hinge -pit, both of which are readily seen 
in my specimen. 
