94 THEORY OF THE EARTH. 



View of the General Results of these Researches. 



Considered with regard to species, upwards of 

 ninety of these animals are most assuredly hither- 

 to unknown to naturalists ; eleven or twelve have 

 so perfect a resemblance to species already known, 

 that the slightest doubt cannot be entertained of 

 their identity ; the others exhibit many traits of 

 resemblance to known species, but their compari- 

 son has not yet been made with sufficient preci- 

 sion to remove all doubts. 



Considered with regard to genera, of the ninety 

 hitherto unknown species, there are nearly sixty 

 that belong to new genera. The other species 

 rank under genera or subgenera already known. 



It may not be without use, also, to consider 

 these animals with regard to the classes and or- 

 ders to which they belong. Of the hundred and 

 fifty species, about a fourth part are oviparous 

 quadrupeds, and all the rest mammifera. Of these 

 last, more than the half belong to non-ruminant 

 hoofed animals. 



Notwithstanding what has been done, it would 

 still be premature to establish upon these numbers 

 any conclusion relative to the theory of the earth, 

 because they are not in sufficient proportion to the 

 numbers of genera and species which may be bu- 

 ried in the strata of the earth. Hitherto the 

 bones of the larger species have been chiefly col- 



