DESCRIPTION OF SHELLS. 173 
single lesser rays occur, particularly in the specimen fig. 30. Fig. 31 is from 
Mr. Edwards’s Collection. 
Pecten quadraginta-radiatus. (Tab. III. fig. 33.) 
Spec. Cuar.—Orbicular, with a rectangular beak, compressed, radiated, and 
squamose ; radii simple, rounded, above forty ; scales small, distant ; ears large, 
radiated. 
The very numerous rays distinguish this shell at first sight ; they equal in size 
the spaces between them, which are convex in the middle. A rare species. 
Spondylus rarispina. 
Occurs in yellow sand with Nummulites, and is much worn; two specimens 
were found ; one is in Mr. Bowerbank’s Collection. 
Ostrea elephantopus. 
Spec. Cuar.—Hemispherical, subimbricated, smooth, heavy, obscurely 
eared ; hinge-line broad and straight, the central pit slightly raised from the 
surface of the shell, broad and deep; margin of the flatter valve thick, its edge 
reflected ; muscular impression orbicular, large, nearly central. 
Diameter 6 or 7 inches, depth 3 or more inches. 
This differs from Ostrea gigantea of Brander (Mineral Conchology, tab. 64) 
in the form of the hinge-pit, which is considerably elevated in that species, and 
in the depth of the hollow valve. It shows the same cellular tissue as Ostrea 
cariosa of the Bognor rock, which may possibly be the young of the same 
species, although such large specimens have not been found at that place. 
There appear to be several species of Oyster resembling O. gigantea found at 
and near Bracklesham, but they seldom have both valves, and are otherwise im- 
perfect, so that in this difficult genus it becomes impossible to define the species 
with any degree of certainty. Mr. Bowerbank possesses a fine collection of them. 
Ostrea picta. (Tab. IV. fig. 1.) 
Spec. Cuar.—Orbicular, uneven, not imbricated ; attached valve very deep, 
the other nearly flat and thickened near the margin ; hinge-area broad, flat, with 
a central pit; muscular impression large, orbicular; both valves striped with 
brown. 
2A 
