m NOTE ON THE FOSSIL CROCODILE 



bone is not observable, and as this is one of the points upon which the 

 Cayman and Crocodile differ, it is perhaps to be regretted that this must 

 remain at present doubtful ; for although the characters above given dis- 

 tinguish the fossil from the Cayman, the bluntness of the muzzle and the 

 proportions of the bones of the head do, in some respects, assimilate it with 

 the latter sub-genus. 



On the lower smooth surface the sutures are well defined, and it is on 

 this measurement that we observe the remarkable distinction between the 

 existing and the fossil animal : the shortness of the maxillary bones and 

 the length of the intermaxillaries, including the nasal aperture, is a peculi- 

 arity that will be observed in the table of measurements, the former 

 (maxillary) in the existing animal being to the latter (intermaxillary) as 

 3.9 is to 3.2. In the fossil as 3.8 is to 4.3. The length of the maxillary 

 bones on the lower suture, or the space separating the palatine from the 

 intermaxillaries, being rather greater in the existing animal of 1 1 feet than 

 in the fossil. The comparative measurement from the point of the muzzle 

 to the maxillary extremity of the palatine bone, together with those across 

 the scull at the 10th and 4th teeth, will point out in a still clearer way 

 the bluntness and breadth of the muzzle of the fossil animal. By the ex- 

 tension of the intermaxillaries and the great length of the connecting suture 

 between the point of the muzzle and the nasal aperture, this aperture is 

 thrown further back, so that a line drawn transversely through the grooves 

 for receiving the 4th lower teeth, (which in the existing animal would cut 

 the posterior extremity,) in the fossil, passes through the centre or rather 

 in front of the centre of the nasal aperture. 



The skulls of the true Crocodile and Cayman differ in the following 

 points. 1 . That of the Cayman is less oblong, shorter, and flatter at the 

 muzzle. 2. The 4th tooth of the lower jaw enters into a hole in the upper, 

 instead of a groove as in the true Crocodile. 3. They differ in the number 

 of teeth. 4. The cranial foramina bounded by the posterior, frontal, mas- 

 toid and parietal bones, are smaller, awd sometimes altogether wanting in 



