FOSSIL REPTILES. 187 



the lower jaw pass into notches of the upper, and not into 

 hollows. The cranium has large foramina behind the eyes, 

 and the hind feet are indented and palmated like those of the 

 crocodiles proper. The slender form of their muzzle renders 

 them, though superior in size, much less formidable than the 

 two other sub-genera. They usually content themselves with 

 fish. 



A brief notice of the species of these sub-genera will be 

 necessary. 



The first is the Pike-muzzled Cayman (Crocodilus lucius), 

 so called by M. Cuvier, who was under the necessity of new- 

 naming all the species, to prevent the confusion which must 

 have resulted from retaining the popular appellations. Several 

 individuals, all from North America, came under the inspection 

 of the Baron ; who, however, hesitates to say that this is the 

 only cayman found in that part of the globe. Dr. Leach has 

 given a figure of it in the "Zoologist's Miscellany," t. ii. p. 117, 

 pi. CII. 



It has all the characters common to the Caymans. Its 

 muzzle is very flatted, the sides are almost parallel, and they 

 unite in front by a parabolic curve. These circumstances give 

 it a striking resemblance to the muzzle of a pike. The internal 

 edges of the orbits are very much raised ; but they are not 

 united by a transversal crest or ridge. The external apertures 

 of the nostrils are from the earliest age separated from each 

 other by an osseous branch, which does not take place at any 

 other age in the other species. The cranium has two oval, 

 oblique fosses, of no great depth ; in the bottom of which are 

 small holes. The nape of the neck is armed in the middle 

 with four principal plates, each of them being raised by a 

 ridge. There are besides, two small ones in front, and two 

 behind. On the back are eighteen transverse ranges of plates, 

 each raised with a ridge. The number of the ridges, or of the 

 plates of each range is as follows : — 



One range with two ridges, two with four, three with six, 



