156 DISTRIBUTION OF EXTINCT ANIMALS. [part 11. 



they flourished in Europe during the Miocene age — animals as 

 large (in some species) as a rhinoceros, and most allied to living 

 African forms. In North America no trace of Edentata has been 

 found earlier than the Post-Pliocene period, or perhaps the Newer 

 Pliocene on the west coast. Neither is there any trace of them 

 in South America in the Eocene formations ; but this may well 

 be owing to our very imperfect knowledge of the forms of 

 that epoch. Their absence from North America is, however, 

 probably real ; and we have to account for their presence in the 

 Old World and in South America. Their antiquity is no doubt 

 very great, and the point of divergence of the Old World and 

 South American groups, may take us back to early Eocene, or 

 even to Pre-Eocene times. The distribution of land and sea may 

 then have been very different from what it is now ; and to those 

 who would create a continent to account for the migrations of 

 a beetle, nothing would seem more probable than that a South 

 Atlantic continent, then united parts of what are now Africa 

 and South America. There is, however, so much evidence for 

 the general permanence of what are now the great continents 

 and deep oceans, that Professor Huxley's supposition of a con- 

 siderable extension of land round the borders of the North Pacific 

 Ocean in Mesozoic times, best indicates the probable area in 

 which the Edentate type originated, and thence spread over much 

 of the Old World and South America. But while in the latter 

 country it flourished and increased with little check, in the 

 other great continents it was soon overcome by the competition 

 of higher forms, only leaving a few small-sized representatives 

 in Africa and Asia. 



