322 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Feb. 9, 
spine, distant about 1 inch from the bottom of the notch between 
the preezygapophyses. ‘The posterior opening of the neural canal is 
much narrower than the anterior: only the upper part of it remains ; 
its sides form an angle of about 80°. 
One of the first questions which arises is, to what region of the 
spine does this vertebra belong? In the almost complete absence of 
the centrum, this question cannot be certainly answered. Its cum- 
brous size, the great platform, and the restraint which the super- 
added median bolt and notch impose on the play of the zygapophyses 
point, I think, to the trunk. Next, the small size and the direction 
of the articular facet at the end of the transverse process appear ill 
suited to constitute it the sole and sufficient vertebral support of a 
rib of dimensions commensurate with those of the vertebra. This 
makes it likely that there was a capitular costal articular surface on 
the side of the centrum; and a double costal vertebral articulation, 
taken in connexion with the other character, points to the front half 
of the trunk. 
The marked reptilian character of the Wealden fauna favours the 
presumption that this is also the vertebra of a reptile. 
Shortly summed, its distinctive features are :— 
Textural.—The compactness of the osseous tissue, its occurrence 
chiefly in thin plates, the thinness of the cortical layer of the bone, 
and the immense spaces of the cancellous tissue. 
Constructive.—1. The vertical median plate, or bolt, beneath the 
postzygapophyses, and the corresponding notch between the pre- 
zygapophyses. 
2. The composite neural spine. 
3. The great platform. 
4. The buttresses and arches by which the spine, neurapophyses, 
transverse processes, and platform are strengthened, and the groined 
interior arch at the front of the neural canal. 
The peculiar textural characters enable us readily to separate 
these from other Wealden bones. My attention was first drawn to 
these four years ago by Mr. Fox, who had already at that time col- 
lected many fragments of this sort from the Wealden cliffs in the 
neighbourhood of Brighstone, not one of which, however, was suffi- 
ciently complete for me to glean an idea from it as to the part of 
the skeleton from which it had come. The texture of these frag- 
ments reminded me more of the coarse diploé of the Elephant’s skull 
than cf any thing else with which I was acquainted. They told of 
the former existence of a large animal distinct from any of the 
known Dinosaurs, having a skeleton comparable for its lightness 
with that of Pterosauria, but of a size far surpasing any of these. 
About a year after this, while examining the Streptospondylian ver- 
tebree in the British Museum, I was struck with the close resem- 
blance, as regards colour and texture, of one of these to the pieces of 
bone which Mr. Fox had shown me, and the suspicion arose in my 
my mind that these were portions of this Streptospondylus. I have 
lately reexamined this vertebra, and find the same textural simila- 
