part 1 .] lycleJcker: Vertebral'a from Tertianes and Secondaries of India. 39 
To the above description I would add that there are no transverse processes; that the 
neural arch is anchylosed to the anterior half of the upper borders of the centrum, the pos¬ 
terior half of the latter being free; that a longitudinal furrow traverses the haemal aspect 
of the centrum ; and that the prezygapophyses are cylindriform and project far forwards. 
We will now inquire to what animal the vertebra; are likely to belong. Firstly, from the 
presence of surfaces for the attachment of chevron bones, from the small size of the neural 
canal, and from the absence of posterior zygapophyses, it is quite clear that the vertebrae 
belong to the caudal region; and secondly, from the absence of transverse processes, and 
from the comparatively small size of the neural spine and prezygapophyses, it is clear that 
they belong to the posterior half of the caudal region. 
The only mammalia of large size which have chevron bones attached to the caudal 
vertebrre are the Edentata and the Cetacea; in the former order all the caudal vertebrae have 
transverse processes, and the centrum is short and cylindrical; in the latter the centrum is 
still shorter and more discoidal. It is therefore clear, independent of their geological position, 
that the bones do not belong to the mammalia. 
Turning now to the reptiles, we find that in the Crocodilia and the Lacertilia the 
posterior caudal vertebra;, though procoelous, have a persistent neuro-central suture; the 
neural arch extends as far back as the centrum ; there are both pre- and post-zygapophyses; 
there is generally a transverse process, and the chevron bones articulate with only one 
vertebra;—so that each vertebra has only one pair of facets on its hinder border for their 
articulation. Orders of reptiles such as the Ichthyosauria, Plesiosauria, Chelonia, Dicyno- 
dontia, etc., have vertebrae of totally different types, and require no comparison with our 
specimens. 
If, however, we turn to the order Dinosauria, we find that here we do meet with vertebrae 
which agree very closely with our present specimens ; if we compare the figure of a posterior* 
caudal vertebra of Pelorosaurtis, figured on Plate 26 of the Philosophical Transactions for 
1850, with Dr. Falconer’s figure of the Jabalpur vertebra (the two figures being taken from 
opposite sides of the bones), we shall find a very great resemblance in many points of essen¬ 
tial structure. Firstly, both vertebrae agree in being elongated, in the absence of any trans¬ 
verse process, in having a neural arch of considerable height, in carrying prezygapophyses, 
but no post-zygapophyses; in the former, being cylindriform and projecting in front of the 
centrum, and in having a small neural canal; moreover, in both, the neuro-central suture is 
completely obliterated, while the neural arch does not extend backwards beyond the middle 
of the centrum, the posterior half of the latter being quite free ; both vertebrae likewise have 
the inferior border of the centrum arched. 
Having now considered the points of resemblance, we must point out the differences 
between our Jabalpur vertebra; and those of Pelorosaurus. The most striking difference is 
that our vertebrae are markedly concave anteriorly and convex posteriorly, whereas those of 
Pelorosaurus are slightly concave anteriorly and nearly flat posteriorly; the latter are also 
approximately cylindrical, and carry facets for the chevron bones only on the hinder ex¬ 
tremity. The caudal vertebras of Iguanodon (Owen, Brit., Oroet. Kep., PI. 37) resemble 
our specimens in carrying two pairs of facets for the chevrons; they differ, however, by being 
thicker, nearly cylindrical, and by the greater length of the neural arch in proportion to the 
length of the centrum. The caudal vertebra; of Cetiosuurus, figured by Professor Philips 
in his Geology of Oxford, are very like those of Pelorosaurus ; but the pre-zygapophyses are 
not cylindrical and do not project so far forward as in Pelorosaurus. The caudal vertebra; 
* This specimen is called by Dr. Mantel ** median caudal j it is, as stated in Philips’ Geology of Oxford (p. 2t>6) 
really a posterior caudal. 
