6l4 MANUAL OF ZOOLOGY. 



temperate climate, and, like the Mammoth, possessed a thick 

 covering of mixed wool and hair. This has been demonstrated 

 by the discovery of a frozen carcass in Siberia. 



Of the Hippopotainidce, the earliest-known species is the 

 Hippopotamus major of the Pliocene period. This form agreed 

 in all essential respects with the living 'H. ampKibius of Africa, 

 but it must have ranged over the whole of Southern Europe. 

 Hexaprotodon, of the Tertiary deposits of the Sivalik Hills of 

 India, is closely allied to Hippopotamus, but had six lower 

 incisors. 



Of the Suida, or Pig tribe, various extinct forms are known 

 from the Eocene and Miocene rocks, where the family is 

 represented by the genera Charopotamus, Anthracotherium, 

 Hyopotamus, and Hippohyus. 



As regards the past existence of the Ruminants, the Cervida, 

 or Stag tribe, is represented, for the iirst time in the Miocene 

 period, by the genus Dorcatherium. The best-known species, 

 however, of this family is the Megaceros Hibernicus, or so-called 

 Irish Elk (fig. 241), which is not a true Elk, but is intermediate 



Fig. 241.— The Irish Elk {Megaceros Hibernicus). 



between the Fallow-deer and Reindeer. A fossil Camel (C 

 Sivalensis) has been discovered in the Tertiary deposits of the 

 Sivalik Hills of India. Of the Giraffe family — represented at 

 the present day by a single African species — a form has been 

 discovered in the Pliocene rocks of Greece, and has been 

 described under the name of Helladotherium. Somewhat 



