8 REPORT OF THE 



now under consideration, it would appear that the head, judging 

 from what remains of the lower jaw, is reduced to the minimum 

 deyelopement, and that the neck (most of the vertebra) 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 

 Mollusca 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 

 Museum. 



