﻿MONOGRAPH 



ON THE 



Genus OMOSAURUS. 



(Continued.) 



Species— OM OSA URUS HAST1GER, Owen. (Plates XXIII and XXIV). 



If the grounds assigned in the former part of this Monograph 1 for the probable 

 homology of the unsymmetrical spine figured in Plates XXI and XXII, which spine 

 was found with the bones of the fore-limb of Omosaurus armatus, should be deemed to 

 warrant such conclusion, a similar one may be provisionally accepted as applicable to 

 the pair of spines of similar size and character discovered in the same division of the 

 Kimmeridge Clay, in the Great Western Railway Cutting at Wootton Bassett, Wiltshire, 

 briefly referred to at p. G 8 of that portion of the Monograph. 



Many large Saurian fossils were collected from the sections of Kimmeridge Clay at 

 that time exposed ; but none have reached me save the subjects of the present Mono- 

 graph, which were there obtained by William Cunnington, Esq., P.G.S., and have passed 

 with the rest of his collection into the possession of the British Museum. The apical 

 portion of each spine has been broken away, but the degree of decrease from the base 

 affords satisfactory grounds for the restoration given in Plate XXIV, the ratio of 

 decrease being less in the present species than in the almost perfect spine of Omosaurus 

 armatus} 



The base of the spine (ib., b) expands from the body, a (Plate XXIV), more suddenly 

 and in a greater degree in Omosaurus hastiger. It is suboval in form and, as in Omos. 



1 Volume of the Palseontographical Society issued for the year 1875, p. 67. 

 3 lb., pi. xxi, figs. 1 and 2. 



