18 



GUIDE TO THE FOSSIL MAMMALS AND BIRDS. 



Table-case Jaws and liiiib-ltones of the desman {Myogale onoschata), au 

 ^*" animal now confined to sonth-east TJussia, are sliown from 

 the Xorfolk Forest Bed. 



Table-case 

 2a. 



Order IV.— CHIROPTERA. 



Fossil skeletons discovered in France prove tliat the bats 

 were as completely formed in the Upper Focene as tliey are 

 at the present day ; Ijut there are only imperfect skulls and 

 jaws in the collection of the ]\lnseum (Tahle-case 2a). 



Pier-eases 



6 10. 



Table-cases 



4, 5. 



Pier-cases 



6-8. 



Table-case 



4. 



Order V.— UNGULATA. 



As the hoofed animals are traced l)ackwards through 

 geological time, the fossils gradually lead to small marsh- 

 dwelling or forest-dwelling predecessors, which were adapted 

 to live on succulent vegetation. The existing tapirs, pigs, 

 peccaries, hippopotamus, and chevrotains, are the least 

 altered survivors of this ancestry ; while the rliinoceroses, 

 horses, cattle, giraffes, deer, and elephants, with effective 

 grinding teeth, are the highest and newest meml»ers of tlie 

 Order. 



Sub-order 1. — Perissodactyla. 



It seems proV)ahle that at the dawn of the Eocene period 

 all the hoofed animals were five-toed ; liut most of them 

 soon Ijcgan to exhibit a tendency towards the reduction of the 

 spreading foot. In one gi'oup comprising the existing tapirs, 

 rhinoceroses, and horses, the whole weight of tlie body 

 gradually became concentrated on the middle toe, so that 

 this gi'ew stout at the expense of the other toes. Thus arose 

 the uneven-toed hoofed animals or Perissodactyla. The 

 tapirs retain four toes on the fore foot, three on tlie liind 

 foot ; the rhinoceroses, three toes on each foot ; and the true 

 horses, only one toe on each foot (see Fig. 9). 



The rhinoceroses, which are restricted to Africa and 

 the Indian region at the present day, wandered far from 

 tropical climes during the Pleistocene j^eriod and ranged 

 over nearly the whole of Europe and Asia, being common 

 even within the Arctic Circle. The northern species 

 (Ehinoccros antiquitatis or B. tichorhinus) seems to have 

 been most closely related to the nearly extinct sqnare-nosed 

 rhinoceros {E. shmis) of Africa. It is commonly known as 



