8 
REPORT OP THE 
now under consideration, it would appear that the head, judging 
from what remains of the lower jaw, is reduced to the minimum 
developement, and that the neck (most of the vertebrae of which 
have been removed and replaced) exhibits the maximum of 
elongation. 
The vertebral column displays many of the spinous processes 
in situ, several of them being in an unusual degree of perfection, 
and it is otherwise remarkable for exhibiting certain structural 
peculiarities, which may probably prove this Plesiosaurus to be 
Plesiosaurus Platyspondylus, a species discovered by Professor 
Owen, since his report to the British Association in 1839. 
Among other additions to the Geological Collection, may be 
noticed a very singular non-descript fossil body, from the lias of 
Whitby, of which the nature has not yet been determined. To 
Mr. Bunting, of Mansfield, Nottinghamshire, the Society is 
indebted for this specimen. 
Several valuable fossils have been presented by the Committee 
of the Yorkshire Naturalists’ Club. Of these, the most remark¬ 
able is a large bivalve shell, from the Chalk, near Flambro’, 
probably of the genus Inoceramus, but distinguished from any 
known species by very peculiar and strongly marked characters. 
Some important additions have likewise been made to the 
tertiary collection, by the British Natural History Society; and 
Mr. Clark, of Cincinnati, has contributed another series of 
choice Silurian fossils from America. 
In other departments of the Museum, the following are 
among the most important of the additions. 
To Mr. Clark, whose name has already occurred in this 
report as a liberal contributor, the Society are also indebted for 
some specimens of North American freshwater shells, of great 
interest, thus enriching our series of this beautiful group of 
Molliisca to the extent of nearly one hundred species. 
The same gentleman has also kindly undertaken to aid the 
Keeper of the Museum, in the revision of the arrangement of 
this portion of our Foreign collection, and is now preparing a 
Catalogue, with notes, upon all the species of American shells 
with which, from time to time, he has enriched the Society’s 
jMuseum, 
