ON THE DERMAL ARMOUR OF JACARE AND CAIMAN 297 
it will be observed, the relations of the same dimensions in the above 
list. 
In the specimen in the British Museum there are eighteen teeth 
on each side above, and fifteen below. The Bordeaux specimen is 
stated to have the same dental formula, except that there are sixteen 
teeth in the left ramus of the mandible. The fourth and tenth 
maxillary teeth are stated by Graves to be as large again as the 
others; and the corresponding alveoli have these proportions to 
one another in the British Museum specimen. In fact, there can be 
no doubt that this skull is that of a true Crocodilus Journet. 
But its general characters at once prove the close affinity of C. 
Journe?t with the other true Crocodiles, from which it differs only in its 
elongated and gradually tapering skull, and in the more backward 
extension of the mandibular symphysis,! which attains the level of 
the posterior margin of the sixth tooth. 
In this character, and in the extreme slenderness of the snout, 
there is doubtless an approximation to MZecistops; but Crocodilius 
Journer is sharply separated from that genus by the characters of 
its teeth, and by those of its dermal armour. 
5. Crocodilus bombifrons (palustris ?). 
All the species of Crocodilus which I have hitherto mentioned 
have, in common, the backward curvature of the premaxillo-maxillary 
suture to the level of the seventh tooth. But there is a species of 
Crocodile, about whose proper specific name I am by no means clear, 
in which this suture passes straight across the palate, or may even be 
a little convex forwards. 
And not only do the skulls of this species exhibit this approxi- 
mation to those of the Adigatoride, but they resemble them still 
further in their rounded snouts, their great width immediately behind 
the canine groove, and in the fact that, in young specimens, one or 
the other canine may be received into a pit instead of into a groove.” 
In the Hunterian Collection there are seven skulls, varying in 
1 The greater proportional length of the symphysis is noted by Duméril and Bibron. 
2 In a skull of this species 144 inches long, in the British Museum, the vomers are com- 
pletely excluded from the palate, and their anterior ends do not extend for an eighth of an 
inch beyond the palatine part of the palato-maxillary suture, which lies on a level with the 
anterior margin of the twelfth alveolus. Each vomer is 23 inches long, and presents the 
same general form as that of /acare ; only the anterior division is but a very small, flat and 
thin plate, not a quarter of an inch long. The boundary of the median nares is formed in 
equal proportions by the vomer and the palatine, and is opposite the fourteenth tooth. The 
hinder end of the vomer articulates with the end of the descending process of the 
prefrontal. 
