90 
JURASSIC; OR 
second and third about equi-distant from each other and the 
first, and placed on the most prominent part of the whorl;— 
one not projecting beyond the other. Base convex ; lines of 
growth ? 
The Litorinse and Turbo in our Oolites have seldom so few 
ribs; and they are generally more roughly-ornamented. 
CHEMNITZIA.-A. Sp. 
Plate 21; fig. 2. 
A minute fossil; scarcely one-third of an inch long; and 
very like numerous other species in Oolitic rocks. The whorls 
are simply rounded; not appressed at the suture; nor oblique. 
The mouth is ovate and rather pointed below. 
The specimen has been lost; and only a general resemblance 
can be traced to such species as C. lineata, Sowerby, which 
appears smooth in its younger state, and is found both in 
Oolite and Lias. Such species are, however, found in all 
rocks. From the Lower Lias the Abbe Stoppani has figured 
a small Chemnitzia and a Pleurotomaria, which remind us 
of the two above species.—Palseont. Lombardie, 3rd 
Series, pi. 2. 
OSTREA ELABELLOIDES• —Deshay es . 
Plate 22, fig. 1. 
Golclfuss., Pet., plate 73, figs. f-i. 
Our fossils are but small, and internal casts only. I should 
have been rather disposed to refer them to the 0. Mars/di, 
Sow., a fossil already described by Sowerby himself from the 
Cutch district. But the ribs of 0. Mars/di are so very sharp 
and high, and made so nodular by the ridges of growth, that 
I prefer identifying with the Inferior Oolite species. 0. jla - 
lelloides has the shape longer, and somewhat rounder and 
lower ribs, and between these ribs are curious pit-like hollows, 
