410 



GENERAL ZOOLOGY. 



and the eastern Malay archipelago. These regions are 

 not all equivalent. The Australian is most markedly 

 separated from the rest, while the Nearctic and the Palse- 

 arctic are closely similar; indeed, are often united as a 

 Holarctic region. 



The Australian region is characterized by the mono- 

 tremes and by the great abundance of the Marsupials, 



FIG. 177. Main geographical regions of the earth. Horizontal lines Palse- 

 arctic; vertical lines, Nearctic; coarse oblique, Ethiopian; fine oblique, 

 Neotropical; cross-lined, Oriental; dotted, Australian. 



forms which occur nowhere else, except a few species in 

 America. The absence of all other mammals, except 

 those which might have drifted there or have accom- 

 panied man, is noticeable. 



The Neotropical region contains the platyrrhine apes, 

 numerous rodents and edentates, and has an almost entire 

 absence of insectivores. The llamas and alpacas are 

 noticeable, while numerous families of birds, among them 

 the humming-birds and the toucans, are characteristic. 



The Ethiopian region u marked by the presence of the 



