58 OSBORN. 



or Indo-Malayan region, and that this accounts for the marked 

 community of fauna between this region and the Ethiopian as 

 obsen^ed by Blanford and Allen. 



Against the prevalent theor)^ of Oriental origin of these ani- 

 mals are : first, the fact observed by Blanford and Lydekker 

 in the Bugti Beds (Sind) that the Oligocene or lower Miocene 

 fauna of the Orient is markedly European in type ; second, that 

 if these animals had originated in Asia some of them would 

 have found their way to North America ; third, the fact that all 

 these animals appear suddenly and without any known ancestors 

 in older geological formations. These are the main facts in 

 favor of the Ethiopian migration hypothesis. 



In the meantime the unification of the North American and 

 Eurasiatic regions was proceeding by intermigration. In the 

 lower Oligocene the giant pigs or elotheres, the tapirs and 

 peculiar amphibious rhinoceroses known as amynodons, found 

 their way from America to Europe, while Europe supplied us 

 with a few anthracotheres, both Anthracotherium and Hyopot- 

 amus. In the Miocene Europe sent us the true cats and we 

 supplied Europe with the destructive sabre tooth tigers ; in the 

 upper Miocene Europe sent us our first deer and cattle or Ccr- 

 vidce and Bovidce, also probably the mastodons en route from 

 Africa. In the Pliocene we supplied Europe with the rabbits 

 and hares, and possibly with the raccoons, if the Panda belongs 

 to this family. In the Pleistocene the camels wandered into 

 Asia from America, while the bears passed them en route to 

 America. These are a few instances out of many which are 

 already well known. 



On the other hand certain families had an exclusi\'ely Eurasi- 

 atic history, so far as we know. These are, among animals re- 

 lated to the horse and tapir, the palseotheres and Lophiodon ; 

 among ruminants the traguline deer and muntjacs ; among in- 

 sectivores the hedgehogs ; among primates, the anthropoid apes 

 and the lemurs. The latter are peculiar to the Malagas)^ and 

 Ethiopian regions. At the same time America exclusively 

 raised the titanotheres, the HyracodontidcE or cursorial rhinoc- 

 eroses, the pouched rodents or Geoinyidcs, all the early families 



