CROCODILIA. 49 



indispensable to the existence and propagation of these most gigantic of living Saurians, 

 concur only in the tropical or warmer temperate latitudes of the globe. Crocodiles, 

 Gavials, and Alligators now require, in order to put forth in full vigour the powers of 

 their cold-blooded constitution, the stimulus of a large amount of solar heat, with ample 

 verge of watery space for the evolutions which they practise in the capture and disposal 

 of their prey. Marshes with lakes, extensive estuaries, large rivers, such as the Gambia 

 and Niger that traverse the pestilential tracts of Africa, or those that inundate the 

 country through which they run, either periodically, as the Nile for example, or with 

 less regularity, like the Ganges ; or which bear a broader current of tepid water along 

 boundless forests and savannahs, like those ploughed in ever-varying channels by the 

 force of the mighty Amazon or Oronooko ; — such form the theatres of the destructive 

 existence of the carnivorous and predacious Crocodilian reptiles. And what, then, 

 must have been the extent and configuration of the eocene continent which was drained 

 by the rivers that deposited the masses of clay and sand, accumulated in some parts of 

 the London and Hampshire basins to the height of one thousand feet, and forming the 

 graveyard of countless Crocodiles and Gavials r Whither trended that great stream, 

 once the haunt of Alligators and the resort of tapir-like quadrupeds, the sandy bed of 

 which is now exposed on the upheaved face of Hordwell Cliff ? 



Had any of the human kind existed and traversed the land where now the base of 

 Britain rises from the ocean, he might have witnessed the Gavial cleaving the waters of its 

 native river with the velocity of an arrow, and ever and anon rearing its long and slender 

 snout above the waves, and making the banks re-echo with the loud and sharp snappings 

 of its formidably-armed jaws. He might have watched the deadly struggle between the 

 Crocodile and Palaeothere, and have been himself warned by the hoarse and deep bellow- 

 ings of the Alligator from the dangerous vicinity of its retreat. Our fossil evidences 

 supply us with ample materials for this most strange picture of the animal life of ancient 

 Britain, and what adds to the singularity and interest of the restored ' tableau vivant,' 

 is the fact that it could not now be presented in any part of the world. The same 

 forms of Crocodilian Reptile, it is true, still exist, but the habitats of the Gavial and the 

 Alligator are wide asunder, thousands of miles of land and ocean intervening : one is 

 peculiar to the tropical rivers of continental Asia, the other is restricted to the warmer 

 latitudes of North and South America ; both forms are excluded from Africa, in the 

 rivers of which continent true Crocodiles alone are found. Not one representative of 

 the Crocodilian order naturally exists in any part of Europe ; yet every fcrm of the 

 order once flourished in close proximity to each other in a territory which now forms 

 part of England. 



