254 THEORY OF THE EAltTH. 



to the waters, do not yet shew bones of quadru- 

 peds, not even of oviparous quadrupeds. 



It is only a little above this, in the bituminous 

 copper-slates, that we see the first traces of them ; 

 and, what is very remarkable, the first quadrupeds 

 are reptiles of the family of lizards, very much 

 resembling the large monitors which live at the 

 present day in the torrid zone. Several indivi- 

 duals of this kind have been found in the mines 

 of Thuringia*, among innumerable fishes of a 

 genus now unknown, but which, from its relations 

 to the genera of our days, appears to have lived in 

 fresh water. Every body knows that the monitors 

 are also fresh water animals. 



A little higher is the limestone called Alpine, 

 and resting upon it the shell-limestone, so rich in 

 entrochites and encrinites, which forms the basis 

 of a great part of Germany and Lorraine. 



In it have been found skeletons of a very large 

 sea-tortoise, the shells of which might have been 

 from six to eight feet in length ; and those of an- 

 other oviparous quadruped of the family of lizards, 

 of a large size, and with a very sharp muzzle f. 



Rising still through sandstones, which present 



* See my " Recherches sur les Ossemens Fossiles," t. v. 

 part ii. p. 300. 



t Id. vol. v. part ii. p. 355 and 525. 



