26 



THE HOBSE 



it walk on the tips of the toes only, as the horse does, but 

 probably habitually stood in an intermediate position, 

 with the heel raised more or less from the ground. 



The remains of animals referable to this genus already 

 discovered in the Wasatch Eocene are remarkably nume- 

 rous, and differences in size and details of conformation 

 have enabled Cope to describe and name nine species 

 considered to be distinct from each other. They vary in 

 size from that of a bulldog to a leopard or sheep. The 

 structure of the bones of the nasal region has led to the 

 suggestion that the head may have carried a short pro- 

 boscis like that of the tapir. 



As mentioned above, Phenacodus is not an isolated 

 form, and allied but less perfectly known species appear 

 to bridge over the interval between it and the next that 

 will be spoken of. 



In the year 1839, Sir Eichard Owen described an 

 imperfect skull of a small animal, not larger than a fox, 

 which was discovered in the London Clay (Lower Eocene) 

 of Heme Bay, in Kent, under the name of Hyracotherium, 

 a name implying a supposed affinity (which we now know 

 it does not possess) to the existing genus, Hyrax} Speci- 



1 ' Hyrax ' (a Greek word for an animr.1 which cannot be identi- 

 fied with certainty, perhaps a kind of shrew) is a name given by 

 modern zoologists to a small group, consisting of about a dozen 

 species, of animals inhabiting the rocky districts of Syria and 

 various parts of Africa, and which are of such peculiar structure that 

 tney are completely separated from all the existing and all the 



