﻿20 



FOSSIL REPTILIA OF THE 



central part of its surface, the peripheral part being smoother than that at the middle, 

 which has yielded to pressure, the large cancelli there having been crushed in. 



The bases of the neurapophyses (PI. V, np), commencing about three lines from the 

 anterior end of the centrum, are continued to the posterior end. They have been 

 anchylosed to the centrum and broken away. Posthumous pressure has crushed this 

 specimen laterally and obliquely. Part of the floor of the neural canal is exposed 

 (at n , n, fig. 5), and is continued outward, at , where the spinal nerve has had issue. 

 The narrowness of the tract of the centrum, between the lateral excavations, /, /, giving 

 support to the coextensive parts supporting the neural arch, is a singular characteristic 

 of the present genus, and made it difficult to conceive that a mere plate of bone like 

 that between / and np in fig. 1, PL V, would relate to the support of a neural arch. 

 It recalled the structure of that part of the vertebras in the thoracic-abdominal region of a 

 Chelonian. What the character of such arch may have been we have yet to learn, in 

 the present species, from better preserved specimens. Not a fragment recognisable as 

 belonging to such portion of the vertebra could be found among the fossils sent up from 

 the Kimmeridge locality at Swindon. 



Two rather more crushed and distorted centrums show, nevertheless, an increase of 

 transverse diameter indicative of their having come from a region of the spine near the 

 sacrum. The centrum shows the same opisthoccelian type, the same wide and deep lateral 

 excavations, undermining, as it were, the neural arch, an absence of transverse processes, 

 and the fractured bases of anchylosed neurapophyses. 



The " Swindon Brick and Tile Company's Works/' whence, through the kindness of 

 the managing director, James K. Shopland, Esq., the above-described fossils were obtained, 

 are situated on land adjoining the Wilts and Berks Canal. The vertebras were found, 

 associated with remains of Pliosaurus brachydeirus, in the Kimmeridge clay, at a depth 

 of fifteen feet. The clay here is of a deep black-blue; and a mass of lignite, 

 seemingly derived from a crushed trunk of a tree, and burning like ordinary coal, was 

 here discovered. 



I was indebted to Richard Jefferies, Esq., of Coate, Swindon, for the first intimation 

 of this discovery, and for a sketch of part of the mandible, 4 feet in length, and of a 

 femur 1 foot 1 inch in length, of the Pliosaurus ; of which Sauropterygian genus an entire 

 tooth, and parts of others, with fractured vertebral centrums, were exhumed from the 

 same pit as contained the vertebras of Bothriospondylus. To Mr. Shopland I am indebted 

 for the transmission of the series of specimens here obtained, which included the evidences 

 of the Dinosaurian genus above characterised. This genus, or type of vertebras, I next 

 proceed to illustrate by larger fossils from other localities and Mesozoic formations. 



