THEORY OF THE EARTH. 253 



Enumeration of the Fossil Animals recognised by the 

 Author. 



In concluding this discourse, there only remains 

 for me now to present the result of my own re- 

 searches, or, in other words, a general account of 

 my great work. I shall enumerate the animals 

 which I have discovered, in the inverse order of 

 that which I have followed in my enumeration of 

 the formations. By proceeding deeper and deeper 

 into the series of strata, I there rose in the series 

 of epochs. I shall now take the oldest formations, 

 make known the animals which they contain, 

 and, passing from one epoch to another, point out 

 those which successively make their appearance 

 in proportion as we approach the present time. 



We have seen that zoophytes, mollusca, and 

 certain Crustacea, hegin to appear in the Transition 

 formations ; perhaps there may even at that pe- 

 riod be bones and skeletons of fishes ; but we do 

 not by any means observe at so early a period re- 

 mains of animals which live on land, and respire 

 air in its ordinary state. 



The great beds of coal, and the trunks of palms 

 and ferns of which they preserve the impressions, 

 although they afford evidence of the existence of 

 dry land, and of a vegetation no longer confined 



