THE EOCENE PERIOD. 



301 



by his researches to form as to the outward appearance of 

 Palceotherit07i tttagnum. Recent discoveries, however, have 



Fig. 229. 



-Outline of Palceotheriunt magnum, restored. 

 (After Cuvier.) 



Upper Eocene, Europe. 



rendered it probable that this restoration is in some important 

 respects inaccurate. Instead of being bulky, massive, and 

 more or less resembling the living Tapirs in form, it would rather 

 appear that Palceotherium magnum was in reality a slender, 

 graceful, and long-necked animal, more closely resembling in 

 general figure a Llama, or certain of the Antelopes. 



The singular genus Anchitherium forms a kind of transition 

 between the Palceotheria and the true Horses {Equidce). The 

 Horse (fig. 230, D) possesses but one fully-developed toe to 

 each foot, this being terminated by a single broad hoof, and 

 representing the ?fiiddle toe — the third of the typical five- 

 fingered or five-toed limb of Quadrupeds in general. In 

 addition, however, to this fully-developed toe, each foot in 

 the horse carries two rudimentary toes which are concealed 

 beneath the skin, and are known as the " splint-bones." 

 These are respectively the second and fourth toes, in an 

 aborted condition ; and the first and fifth toes are wholly 

 wanting. In Hipparion (fig. 230, C), the foot is essentially 

 like that of the modern Horses, except that the second and 

 fourth toes no longer are mere " splint-bones," hidden be- 

 neath the skin ; but have now little hoofs, and hang freely, 

 but uselessly, by the side of the great middle toe, not being 

 sufficiently developed to reach the ground. In Anchitherium, 

 again (fig. 230, B), the foot is three-toed, like that oi Hipparion; 

 but the two lateral toes (the second and fourth) are so far 

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