298 ON THE DERMAL ARMOUR OF JACARE AND CAIMAN 
length from 5} inches up to 16 inches, in none of which does the crown 
of the premaxillo-maxillary suture extend beyond a line joining 
the sixth pair of teeth. [n all there are two short ridges (conver- 
gent in young specimens, nearly parallel in old ones) upon the lachry- 
mal bones, which end before reaching the anterior limits of those 
bones. They all have an oblique ridge on the upper jaw above the 
tenth tooth ; and the snout attains the width which it has opposite 
this tooth immediately behind the canine groove. In the British 
Museum there are five middle-sized skulls with the same characters ; 
but two of these have a pit on one side of the upper jaw, and a groove 
on the other, and one has something between a pit and a groove on 
each side. 
Dr. Gray has in his “ Catalogue,” + mentioned the peculiar trans- 
verse disposition of the premaxillo-maxillary suture in his Crocodilus 
bombifrons ; and on examining the two crania thus named in the 
British Museum collection, one of which is 20 and the other 21 inches 
long, I can discover no distinguishing character between them and 
those already described. There can be no doubt then, I think, that 
these constant and well-marked characters, exhibited by fourteen 
skulls which vary in length from 54 to 21 inches, prove the existence 
of a distinct species of Crocodile, which I would_ provisionally term 
bombitrons. 
I believe that this species has been constantly confounded with 
biporcatus, from which it may be at once distinguished by the direc- 
tion of the premaxillo-maxillary suture, and by the shape of the snout 
behind the canine groove. I have ound these distinctions to hold. 
good at all ages; but the last-mentioned difference is far more 
marked in middle-aged than in either young or old specimens. 
All the skulls named Crocodilus palustris which I have seen are 
referable either to C. dzporcatus or to C. bombifrons. With respect 
to the C. palustris of Lesson and Duméril and Bibron, the latter 
authors consider it to be only a variety of C. vulgaris. Their descrip- 
tion would, however, apply very well to C. dombifrons, as I have 
defined it above; and they expressly state ((Erp. Générale,’ t. iii. 
p. 113) that all their specimens twelve in number and varying in 
length from 30 centimetres to more than 3 metres) came from the 
East Indies or the Seychelle Islands. Now, Duméril and Bibron 
enumerate only three Asiatic Crocodiles—C. dzporcatus, C. palustris, 
and C. galeatus, the last of which was only known to them by descrip- 
tion ; so that all the numerous Asiatic crocodiles which passed through 
1 “ Catalogue of the Tortoises, Crocodiles, and Amphisbeenians in the Collection of the 
1844, p. 59. 
British Museum,” 
