FOSSIL REPTILES. 245 



The length of the cranium, and of all that surrounds it, cor- 

 responds to the length of the crotaphite foramina, in conse- 

 quence of which the orbits are carried forward much more in 

 proportion than in the gavial. 



The frontal of the fossil is not concave, as in the gavial, but 

 flat. It is less emarginated by the orbits. Their edges are 

 not raised ; from which it results, that the bones which form 

 these edges, the anterior frontals, the lachrymals, and the 

 jugals, have a more even form, and by no means concave. 

 The anterior frontals are much larger in proportion in the fossil 

 than the lachrymals. 



There is one thing especially worthy of remark in the fossil : 

 instead of the slight emargination of the orbital edge of the 

 anterior frontal which is in the gavial, there is a smooth demi- 

 canal, which descends on thejunction of the anterior frontal and 

 nasal bones. The nasal, instead of re-ascending entire along the 

 internal edge of the lachrymal and the anterior frontal, widens 

 to embrace the point of the anterior frontal in an emargination 

 of its base. The external apophysis of this base separates the 

 lower point of the jugal from the lachrymal and the anterior 

 frontal. 



The base of the muzzle below, at the spot where the palatines 

 enter into its composition, is much more gibbous, and more 

 high vertically in the fossil than in the gavial. These charac- 

 ters were confirmed by the examination of another fragment 

 unnecessary to be described here. 



This distinction of two species shown by the lower jaws, and 

 confirmed by the examination of heads, was further corroborated 

 by many portions of the skeleton. An attentive examination 

 of the vertebrae proved that they form two systems, and would 

 have indicated the existence of two crocodiles in these marly 

 strata, of difierent species, even if it had not already been 

 recognized by the examination of the jaws. The vertebrae 

 afforded even more positive demonstrations of this fact. In 

 the first specimen examined, the atlas and axis were found sol- 



