678 . MANUAL OF ZOOLOGY. 



the animal to construct extensive burrows. The skin is very 

 thick, and is thinly covered with bristly hairs ; and the tail is 

 hairy. The head is elongated, and the mouth small devoid 



Fig. 375. Skull of Orycterofius capensis. 



of incisor and canine teeth (fig. 375), but furnished with a 

 number of cylindrical molars {^\ The crowns of the molars 



are flat, and they are composed of dentine traversed by nu- 

 merous dichotomising pulp-cavities, their cross-section resem- 

 bling a piece of bamboo cut across. The tongue is long, flat, 

 and slender, and is covered by a sticky saliva, by the aid of 

 which the animal catches insects. The head is long and 

 attenuated, the snout truncated and callous, and the ears large, 

 erect, and pointed. Other species of Orycteropus occur in 

 Senegal and Southern Nubia. 



As regards their distribution in time^ the oldest Edentates at 

 present known occur in Europe, in which country no members 

 of the order now exist. These are the Macrotherium and 

 Ancylotherium of the Miocene Tertiary, both apparently allied 

 to the Orycteropida, with affinities to the Manidce. The Plio- 

 cene deposits of North America have yielded to the researches 

 of Professor Marsh two large Edentates of the new genus Moro- 

 therium, and the Miocene deposits of the same country con- 

 tain remains of another Edentate type {Moropus}. It is, how- 

 ever, in the Post-tertiary deposits of the American continent, 

 and especially of South America the present metropolis of 

 the order that we find the most abundant and the most re- 

 markable remains of Edentate animals. Here, both in Post- 

 pliocene superficial deposits and in cave-earths of the same 

 age, we meet with the remains of numerous Edentates often of 

 gigantic size, but in the main representing the existing types. 



Thus the existing Sloths are represented in the Brazilian 

 bone -caves by a number of extinct genera of Bradypodidcz, 



