I2( 



CLASS MAMMALIA. 



cranium is low and elongated ; and, especially in the type species 

 (fig. 1 1 68), approximates to that of the Myrmecophagidce. The 

 length of the nasals is subject to great variation in the different 



Fig. 1168. — Frontal aspect of the cranium of Scelidotherium leptocefihalum ; from the 

 Pleistocene of South America. One-sixth natural size. 



species. The structure of the feet shows a marked deviation from 

 that of Megatherium ; and the humerus was usually provided with 

 a foramen. The figure of the skeleton is taken from a specimen 

 in the museum at Bologna. The genus Mylodon (fig. 1169) corn- 



Fig. 1169. — Mylodon robnstus ; from the Pleistocene of South America. Much reduced. 



prises another group of large Ground-Sloths, which has been split 

 up by some writers into the genera Lestodon^ Pseudolestodon, Grypo- 

 therium, &c, according to certain not very important differences in 



