THEORY OF THE EARTH. 277 



as the Nile, the Ganges, and the Orinoko, has 

 been very abundant in the places where the palae- 

 otheria lived. Vast quantities of its remains are 

 found at Montmartre *, and in the molasse sand- 

 stones of the Dordogne, and the other gravel de- 

 posits of the south of France. 



The fresh-water lakes, around which these va- 

 rious animals have lived, and which had received 

 their bones, nourished, besides the tortoises and 

 crocodiles, some fishes and testaceous mollusca. 

 All that have been collected of these two classes 

 of animals, are as foreign to our climate, and even 

 as much unknown in our present waters, as the 

 palaeotheria, and other quadrupeds which were 

 coeval with themf. 



The fishes have even in part belonged to un- 

 known genera. 



Hence, it cannot be doubted that this race of 

 inhabitants, which might be termed the popula- 

 tion of the middle age, this first great production 

 of mammifera, has been entirely destroyed ; and, 

 in fact, in all places where remains of them have 

 been discovered, there are great deposits of marine 

 formation above them, so that the sea has over- 

 whelmed the countries which these races inhabit- 



* " Researches," vol, v. part ii. p, 223 and 227. 

 t Id, vol, iii, p, 338, 



