In the Hunterian Collection there are seven skulls, varying in length from 5-1/4 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. In all there are two short ridges (convergent in young specimens, nearly parallel in old ones) upon the lachrymal 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[6],' mentioned the peculiar transverse 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 5-1/4 to 21 inches, prove the existence of a distinct species of Crocodile, which I would provisionally term _bombifrons_. [5] In a skull of this species 14-1/2 inches long, in the British Museum, the vomers are completely 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 2-3/8 inches long, and presents the same general form as that of _Jacare_; 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. [6] 'Catalogue of the Tortoises, Crocodiles, and Amphisbænians in the Collection of the British Museum,' 1844, p. 59. I believe that this species has been constantly confounded with _biporcatus_, from which it may be at once distinguished by the direction of the premaxillo-maxillary suture, and by the shape of the snout behind the canine groove. I have found 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.