2O0 TYPES OF ANIMAL LIFE 



limbed animal which was originally supposed to be allied 

 to rabbits, rats, and other gnawing animals, or rodents. 

 Cuvier, however, was led by various points in its anatomy, 

 and especially by the structure of its teeth, to associate it 

 with the rhinoceros, in spite of its being entirely clothed 

 with hair, instead of the hairless, folded hides of the great 

 nose-horned beasts of India and South Africa. 



Such are the forms of ungulate life now to be found 

 on the surface of this planet, and such the relationships 

 which appear to exist between them. There is a relatively 

 small group of odd-toed beasts containing the three very 

 distinct forms — the horse, the rhinoceros, the tapir — 

 and there is a very large group of even-toed beasts 

 divisible into the two sections, one of swine-like beasts 

 and the other the vast assemblage of ruminants whereof 

 the American bison, or buffalo, is an extreme modifica- 

 tion. Besides these there are the two outlying forms — 

 the elephant and the hyrax — between which and the 

 ungulates no connection now exists. But if we go back- 

 ward in time a very different prospect opens before our 

 eyes. We need only consider the tertiary rocks, the 

 oldest of which is the Eocene formation, and as we recede 

 we shall find a number of gaps to be filled up, the 

 relative proportion of forms to become vei-y different, 

 while relationships, previously unsuspected, between 

 the ungulates as a whole and other orders of beasts 

 suggest themselves to our minds. Thus, the tertiary 

 rocks of France, India, and North America have 

 supplied us with a series of fossil remains which almost 

 entirely bridge over the chasm now existing between the 

 non-ruminating, swine-like beasts, and the ruminants. 

 One of the most interesting, but also one of the most 

 peculiar, of these was also one of the earliest known, 

 having been described and carefully figured by Ouvier 



