HISTORY OF THE PERISSODACTYLA 355 



together, and these, with the thigh-bones, were the longest 

 segments of the Umbs. The special peculiarity of these ani- 

 mals was in the character of the feet, which had three toes, 

 each armed with a huge claw, instead of terminating in a hoof, 

 as it does in all normal perissodactyls. The external digit, 

 which, in the absence of the fifth, was the fourth, was the largest 

 of the series and apparently bore the most of the weight, a 

 notable departure from the normal perissodactyl symnietry, 

 in which the third or median toe is the largest. The hind 

 feet were considerably smaller than the fore, but had similar 

 claws. 



Many suggestions have been offered as to the manner in 

 which these great claws were employed. The teeth demon- 

 strate that these animals could not have had predaceous habits, 

 but must have been inoffensive plant-feeders. As no such 

 herbivorous creatures are living now, it is impossible to reach 

 a definitive solution of the problem, which is further compli- 

 cated by the fact that in two other orders of hoofed mammals, 

 Artiodactyla and fToxodontia, a more or less similar trans- 

 formation of hoofs into claws took place, and among the eden- 

 tates the large, herbivorous fground-sloths (fGravigrada) had 

 enormous claws. It is inadmissible to suppose that these 

 great fchalicotheres could have been burrowers, or tree- 

 cUmbers, or that they pursued and slaughtered prey of any 

 kind, for, aside from the character of the teeth, such heavy and 

 slow-moving beasts would have been utterly inefficient at 

 work of that sort. No doubt, the claws were used, to some 

 extent, as weapons of defence, as the existing South American 

 Ant-Bear (Myrmecophaga jubata) uses his formidable claws ; 

 probably also some, if not all, of these clawed ungulates would 

 employ the fore feet in digging for roots and tubers, as is done 

 by the bears generally. Many years ago, the late Sir Richard 

 Owen suggested with reference to the. fground-sloths that the 

 principal use of the fore feet, other than that of locomotion, 

 was to draw down within reach of the long tongue and pre- 



