94 EKOCENE MOLLUSCA. 
subangulatd ; ared connexis angustdé; sulcis raris ewaratd; marginibus denticulatis ; 
dentibus lateralibus tribus. 
Shell transverse, ovately oblong, inflated, thick, oblique, and inequilateral, striated and 
decussated, slightly compressed in the middle of the shell; pedal region short ; ligamental 
area rather narrow, with few and obsolete chevron-form marks; margins denticulated, 
three lateral teeth on each side. 
Length, 2: inches ; breadth, 13 inch. 
Localities. Faversham (Crowe), Herne Bay, Richborough, Oakwell, near Faversham, 
Nash Park, near Boughton (Prestwich). 
This shell is considered by Professor Morris, in his ‘ Catalogue of British Fossils,’ as 
identical with Cucullea crassatina, Lamk. ; but, although there is a very close approxima- 
tion, I am doubtful of their identity ; and, as I am not imposing a new name, I prefer 
the British fossil should remain with the one under which it was figured and described by 
Parkinson and Sowerby. 
On a comparison of the English shells with specimens in my own cabinet from 
Beauvais, I find the following differences :—The French shells appear to be more inflated, 
and they have a more prominent, angular, and distinct ridge diagonally across the 
syphonal region, and the English shells are comparatively longer; neither can I see the 
great inequality between the two valves which is so conspicuously shown in the French 
specimens ; the rays upon our shell are large, wide, flat, and bipartite, and these rays are 
more nearly alike upon®the two valves than are thoseof C. crassatina, The dental area is 
furnished with a few teeth at each extremity of the lme; those on the siphonal side are 
about three or four in number, and parallel with the hinge-margin ; at the opposite ex- 
tremity there are about the same number, and they are also inclined; all of them are 
vertically striated, or rather denticulated, but more finely so than are either of the French 
species, and in the centre of the hinge-line are a few small teeth in a vertical direction ; 
these are also finely nodulous ; the margin is crenulated by the outcrop of the rays. 
PECTUNCULUS, Lamarck, 1789. 
Gen. Char. Shell equivalve, orbicular, convex, or lenticular, nearly equilateral, smooth, 
or radiately striated ; umbones central, generally distant, divided by a striated area for 
connexus, which is wholly external or ligamental; hinge with a curved row of transverse 
or angular denticles ; adductors nearly equal, palleal line simple, margins crenulated ; the 
shells in the living state are generally covered by a thick and velvety epidermis. 
Animal with the margins of the mantle simple, sometimes studded with minute ocelli ; 
foot large, crescent-shaped, capable of considerable expansion, so as to form a disc, on 
which it is said to be able to move; this foot is supplied with retractor-muscles, the im- 
