6 THORACOSAURUS. 
fossil head about three and a-half feet in length. If we allow as many vertebre 
to the New Jersey Gavial as are possessed by the existing species, or the same pro- 
portionate length of body to the head, the former animal in its entire condition 
would measure twenty feet in, length. 
The upper view of the fossil skull, represented in Fig. 1, Plate I, bears a strong 
resemblance to that of the living Gavial, except that the boundaries of ‘the orbits 
are not conspicuously everted as in the latter, and the muzzle is not so abruptly 
narrowed forward. In the characters just mentioned the fossil appears intermediate 
to the Gavial and Mecistops, and resembles the Teleosauri of the Liassic formations 
of Europe, but most closely the Cretaceous Gavialis macrorhynchus. The posterior 
and lateral outlines of the cranium are the same in both the New Jersey and living 
Gavials, as is also the form of the large temporal foramina. The space separating 
the latter in our fossil, formed by the symmetrical parietal, is both relatively and 
absolutely narrower than in the living Gavial. The forehead, as formed by the 
frontal and pre-frontals, has almost the same proportionate breadth as in the latter, 
but is only slightly concave in consequence of the non-eversion of the orbital 
borders. The frontal in the fossil, as is also the case in the Gavialis macrorhynchus, 
is prolonged considerably more posteriorly to join the parietal than in the recent 
Gavial or Mecistops. The orifices of the orbits, when perfect, appear to have had 
nearly the same proportionate size and form as in the living Gavial, but their horders 
in no position are everted, not even so much as in Mecistops, or the Alligator, A. 
Mississipiensis, 
The post-frontals, separating the orbits from the temporal foramina, are propor- 
tionately narrower than in the recent Gavial; while the post-orbital arches, formed 
through conjunction of the post-frontals with the malars, are broader. 
As in the extinct Gavialis macrorhynchus, the face in advance of the forehead 
and orbits in the New Jersey fossil slopes with a gentle curve forward to the broken, 
end of the muzzle. i 
The malar and lachrymal are more prolonged upon the face or muzzle than in the 
recent Gavial. Thus in the latter, the anterior border of the malar reaches as far 
forward as the position of the fourth tooth, counting from behind, and the lachrymal 
advances as far as the sixth tooth. In the fossil the malar extends as far forward 
as the seventh tooth, and the lachrymal reaches beyond the position of the ninth 
tooth. 
The posterior extremities of the nasals are angular, and extend back on a line 
with the anterior orbital margins. They widen forward to the anterior ends of the 
pre-frontals, then very gradually narrow forward a short distance beyond the lach- 
rymals, and finally narrow abruptly into a pair of linear prolongations extending to 
the broken end of the fossil. A similar condition of the nasal bones is observed to 
exist in the Gavialis macrorhynchus. 
The surface of the cranium, as formed by the parietal, mastoids, frontals, pre- 
and post-frontals, is less foveated than in the full-grown Gavial of the Ganges ; and 
the surface of the muzzle is likewise rather less coached though perforated by 
as many vasculo-neural foramina. 
On both sides of the face, in the fossil, there is a large hole, situated between 
