MATTHEW. CLIMATE AMJ EVOLUTION 



187 



rea-ion includes most ol' the United States and northern Mexico; the 

 corresponding sul^region in the western lialf of the Old World is the 

 Mediterranean, including Europe south of the Alps and Pyrenees, part 

 of southwestern Asia and Africa north of the Sahara desert. 



The Oriental region corresponds in the eastern part of the Old World 

 to the Mediterranean and Sonoran subregions, but, partly because it in- 

 cludes the great East Indian islands and partly because of the barrier 

 interposed by the Himalayan ranges, it is more clearly differentiated 

 from the Holarctic and may best be regarded as a region of itself. 



Fig. .5. — Characterislic features of the mammal faiince in different zooloyical regions at 



successive epochs of the Cenozoic 



Austromalaya is the debatable ground between the Oriental and the 

 very distinct Australian region; but the consensus of opinion classes it 

 by preference with the Australian. It includes Celebes, the Moluccas, 

 Timor and smaller islands and is separated from the Oriental region by 

 "Wallace's Line." 



The Australian region includes Australia, Xew Guinea and Tasmania 

 and is the most remote and archaic of all the great (continental) regions 

 of the globe. New Zealand is included in the Polynesian (island) region. 



The Ethiopian region is connected with the Holarctic by the Mediter- 

 ranean sui^region. It is perhaps more distinct than the Oriental, cer- 



