276 THE HORSE AND ITS RELATIVES 



ultimate ancestor of the horse. But, as pointed 

 out by Dr. Lull, 1 this animal is far too large, and 

 in some respects too specialised, to have occupied 

 such a position. Nevertheless, its five-toed feet 



Front View of the Bones of the Right Fore (a) and Hind (b) Feet of the 

 American Eocene Phenacodus primcevus, natural size 



afford a fair idea of what those of the ultimate 

 ancestor may be expected to have been like. 



Phenacodus belongs to a group of early and 

 generalised ungulates forming a suborder the 

 1 op. dt., p. 163. 



