188 FOSSIL REPTILES. 



six with eight, two with six, and the rest with four. The un- 

 equal ridges sometimes found on the sides are not reckoned 

 here. 



These ridges are tolerably elevated, and nearly equal ; but 

 on the tail, as in all the crocodiles, the lateral ridges predomi- 

 nate, until they unite. There are nineteen transversal ranges 

 of them as far as the union of the two crests, and as many 

 after. It is to be observed, however, that these two numbers 

 are more subject to variation than those of the ranges of the 

 back. 



One individual of this species measured but five feet ; and 

 the longest seen by M. Cuvier was not more than from six to 

 seven. According, however, to the accounts of travellers, this 

 species grows as large as any other ; and Catesby, in particular, 

 says, that he has seen some fourteen feet in length. The 

 breadth of the cranium, at the articulation of the jaws, makes 

 one half of its length ; by which it will be found that the 

 muzzle of this species is both wider and longer than those of 

 the following. 



This species seems adapted to a northern climate, and has 

 been found as high as 32J° north latitude, even in the depth 

 of a rigorous winter. In Louisiana, they throw themselves 

 into the marshes when the cold commences, and fall into a 

 lethargic sleep without being frozen. Their lethargy is so 

 complete, that they may be cut in pieces without being 

 awakened. 



The Spectacled Cayman {Crocodilus Sclerops) is the most 

 common in Cayenne. Its muzzle, though wide, has not the 

 edges parallel. They proceed, approximating throughout 

 their entire length, and forming a figure rather more triangular 

 than in the preceding species. The surface of the bones of 

 the head is very unequal, and appears throughout as if rotted, 

 or gnawed into small holes. The interior edges of the orbits 

 are greatly raised. From their anterior angle springs a project- 

 ing rib-like bone, which extends in front, and a little outwards 



