THEORY OF THE EARTH, 247 



Our formations containing fresh-water shells, 

 have been seen in England, in Spain, and even 

 so far as the confines of Poland. 



The marine shells interposed between them, 

 have been found along the whole course of the 

 Appenines. 



Some of the quadrupeds of our gypsum depo- 

 sits, our palseotheria, for example, have also left 

 their bones in certain gypseous formations of the 

 Velai, and in the molasse quarries of the south of 

 France. 



Thus the partial revolutions which have taken 

 place in our neighbourhood, between the period 

 of the chalk and that of the great inundation, 

 and during which the sea threw itself upon our 

 districts or retired from them, had also taken 

 place in a multitude of other countries. It seems 

 as if the globe had undergone a long series of 

 changes by which variations were produced, proba- 

 bly in close succession, as the deposits which they 

 have left nowhere shew much thickness or soli- 

 dity. The chalk has been produced by a more 

 tranquil and more continuous sea ; it contains only 

 marine productions, among which there are, how- 

 ever, some very remarkable vertebrate animals, 

 but all of the class of reptiles and fishes ; large 

 tortoises, vast lizards, and other similar animals. 



The formations anterior to the chalk, and in 

 the hollows of which the chalk is itself deposited, - 



