PART II. 



Order— CROCODILIA. 

 CROCODILES, ALLIGATORS, GAVIALS. 



Of the numerous and various kinds of Reptiles, the fossil remains of which have 

 been discovered in the tertiary and secondary strata of Great Britain, many are 

 found to have their nearest representatives, amongst the actual members of the 

 class, in the present order ; and here more particularly in the long and narrow-snouted 

 genus called, through a corrupt latinization of its native name, Gavialis, which is now 

 represented by the Gavial or, more properly, Garrhial, of the river Ganges. 



In the interpretation of the fossil remains of Reptiles, no skeleton has more 

 frequently to be referred to than that of the Gavial or Crocodile, or has thrown more 

 light on the nature of those singularly modified forms of the class which have long 

 since passed away. 



It is accordingly requisite for the palaeontologist who would describe the fossil 

 remains of reptiles, to make himself, in the first place, thoroughly conversant with the 

 osteology of the recent Crocodilia. This knowledge can be gained only by assiduous 

 study of the skeletons themselves, with the aid of the best descriptions, or the guide 

 of a competent teacher. But to enable the reader to follow or comprehend the 

 description of the fossil Saurians, some elementary account of the Crocodilian skeleton 

 is at least necessary, accompanied with illustrations of the parts which, in the sequel, 

 will have to be frequently referred to under special or technical names. 



In Tab. XI of the present part of this Monogragh is given a reduced or miniature 

 side view of the skeleton of a Gavial which was twenty-five feet in length — dimensions 

 which are rarely found to be surpassed in the present day. Beneath it is a restoration 

 of the skeleton of the Teleosaur, or extinct Gavial of the Triassic or Oolitic period, 

 showing how closely the general type of conformation has been adhered to, the modi- 

 fications of the more ancient form of Crocodile evidently adapting it for moving with 

 greater speed and facility through the water, and indicating it to have been more 

 strictly aquatic, and probably marine. 



The particular nature of these modifications will be explained when I come to 

 describe the Crocodiles of the secondary strata. I propose at present to give a pre- 

 liminary sketch of the osteology of the recent Crocodilia. 



A glance at a natural or well-articulated skeleton of one of these reptiles, such as 



