CHAEACTEES 01" EECENT CEOCODILTA. 11 



are visible ou the palatine face of the skiill. The premaxillo- 

 maxillaiy suture reaches back, iudeed, to the line of the seventh 

 tooth ; but it forms an even curve whose summit is in the middle 

 line. The aperture of the posterior nares, again, has a totally dif- 

 ferent form from that which it assumes in the adult. It is some- 

 what heart-shaped, with its apex forwards, measures -^ inch long 

 by T%ths at broadest, and looks altogether downwards, while its 

 anterior margin is situated far more forward in the palate than 

 that of the adult. 



2. Crocodilus biporcatus. 



This, the best-known Crocodile, is a very well-marked species, 

 characterized (beside the peculiarities of its dermal armour) by a 

 comparatively slender skull, similar in shape to that of C. vul- 

 garis, and, like it, without any sudden enlargement immediately 

 behind the canine groove ; and by the strong ridge which arises 

 on each lachrymal bone close to the anterior edge of the orbit, 

 and is continued forwards on to the line of junction of the nasal 

 and maxillary bones, so that the naso-maxillary suture traverses 

 the axis of the ridge, and then curves outwards, descending 

 towards the alveolus of the tenth tooth. The premaxillo-max- 

 illary suture is W-shaped ; and its salient angles reach backwards 

 even to the level of the posterior margin of the seventh alveolus. 



3. Crocodilus Americanus (acufus, Cuv.) 

 has the slenderness of snout (even more marked) and the form of 

 the premaxillo-maxillary suture of the preceding species ; but it is 

 at once distinguished from this and all other Crocodiles (except 

 C. rhomhifer) by the marked longitudinal and transverse convexity 

 of the middle of the face, which gives the profile a totally different 

 aspect from that of the other species, which are flat or concave in 

 this region. 



4. Crocodilus Journei 

 is another unmistakeably distinct and very remarkable species. 

 The descriptions and figures given by Graves, Bory de St. Vincent, 

 and Dumeril and Bibron, of the imique specimen of this Crocodile 

 in the Bordeaux Museum, would alone have compelled me to difier 

 entirely from the view taken by Dr. Gray of the affinities of this 

 species. These observers agree in stating that Crocodilus Journei 

 has six cervical scutes, arranged as m the other Crocodiles, and, as 

 Graves says, " separated by an interval of four inches" from the 

 commencement of the tergal scutes, whence it is obviously impos- 



