CRETACEOUS REPTILES. 391 
(heemapophyses) : according to which the vertebra that first was joined to the 
sternum by sternal ribs would be reckoned as the first ‘ dorsal,’ and all anterior 
to it as ‘ cervical vertebre.’ This arbitrary character would agree with that by 
which the cervical vertebre are, in point of fact, defined in the Human subject 
and mammalia generally. 
In the fossil Lacertian, however, which forms the more immediate subject of 
this description, there is no indication of a junction of the vertebral rib (pleur- 
apophysis) by a sternai rib (hemapophysis) with a sternum (hemal spine), and I 
can only compare the cervical region of the spine with that in existing Lacertians, 
insofar as relates to the vertebre situated between the skull and the scapular 
arch. The number of vertebrz so situated in modern Lacertians is usually five, 
and rarely exceeds six: in the Dolichosaurus it was seventeen. In modern 
Lacertians the bodies and neural arches of such cervicals are scarcely inferior in 
breadth to the succeeding vertebre, and commonly surpass them in depth by 
reason of the largely developed inferior spinous processes. The short anterior 
pleurapophyses are usually thick, broad, and expanded at their extremities, or are 
‘hatchet-shaped’ (Cyclodus, Tiliqua, Scincus). Besides the superior number of 
the cervicals in the Dolichosaurus, they exhibit a more decided decrease of size 
as they approach the head: the pleurapophysis of the third or fourth vertebra 
is short, almost straight, and very slender: that of the eighth or ninth vertebra 
is also very slender, and but a little longer: those of the three succeeding 
vertebre progressively though slightly increase in length, but the vertebral ribs 
do not exhibit their normal length until the seventeenth or eighteenth vertebra : 
the pleurapophysial character of these eighteen or twenty anterior vertebre is 
much more like that of the same vertebre in the Ophidian than in the existing 
Lacertian reptiles: and there is no trace of any of the vertebral ribs having 
supported sternal ribs, or having been attached by these to a sternum. The 
slender anterior ribs increase in length, however, more gradually in the Dolicho- 
saurus than in Serpents. 
The parietal and occipital regions of the fossil skull, with the atlas and dentata, 
have been too much crushed to allow of their structure being accurately determined 
and compared: the first tolerably entire vertebra appears to be the fourth from the 
head : the expanded back-part of the neural arch receives the contracted fore- 
part of that arch of the fifth vertebra: the base of the neural spine is slightly 
expanded posteriorly. In the fifth and succeeding vertebre the anterior articular 
processes look upwards, the posterior ones downwards, and they are simple as 
3E2 
