268 THEORY OF THE EARTH. 



resembling (P. medium), but differing from it in 

 the form of its lower jaw ; in the neighbourhood 

 of Orleans, in strata of marly rock, a species (P. 

 aurelianense) *, which is distinguished from the 

 others by having the re-entering angle of the cres- 

 cent of its lower grinders split into a double point, 

 and by some differences in the necks of the upper 

 grinders ; near Issel, in a bed of gravel or molasse, 

 along the declivities of the Black Mountain, a 

 species (P. isselanum) f , which has the same cha- 

 racters as the Orleans species, but is of smaller 

 size. It is more particularly, however, in the 

 molasse of the Department of the Dordogne, 

 that the palaeotherium occurs not less abundantly 

 than in our gypsum deposits in the neighbour- 

 hood of Paris. 



The Duke Decaze has discovered in the quar- 

 ries of a single field, bones of three species which 

 appear different from all those of our neighbour- 

 hood i. 



The Lophiodons approach still somewhat nearer 

 to the tapirs than the palaeotheria do, inasmuch 

 as their lower false grinders have transverse 

 necks like those of the tapirs. 



* Researches, vol. iii. p. 254 ; and vol. iv, p. 498. and 499, 

 t Ibid, vol, iii. p, 258. ^ Ibid. vol. v. part ii. p. 505, 



