n NOTOGAEA, NEOGAEA, AND ARCTOGAEA 85 



the realm of Notogaea), and Madagascar ; and finally, the realm 

 of Antarctogaea or Atheriogaea, which embraces New Zealand, 

 the Antarctic continent, and a series of islands such as South 

 Georgia and Kerguelen, and possibly even the extreme south of 

 Patagonia. This latter quarter of the globe will need no further 

 reference, as it has no truly indigenous terrestrial mammalian 

 inhabitants. We cannot include the Bats in this statement, as 

 their distribution is due to different powers of extending their 

 range, and to different barriers from those which govern the 

 range of other groups of mammals. 



(1) Notogaea. 1 This realm is characterised by the exclusive 

 possession of the Monotremes : that is to say, one of the two 

 primary divisions of the Mammalia is absolutely restricted to 

 this area. It contains, moreover, the vast majority of the 

 Marsupials. Further, the realm of Notogaea is to be dis- 

 tinguished by the entire absence of the higher mammals, with 

 the exception of a few small Eodents. (The Bats are ignored 

 for the reasons stated, and the Dingo is believed to have been an 

 importation.) It cannot be disputed that this is a very distinctly- 

 marked area of the earth's surface. 



(2) Neogaea. The continent of South America has no 

 Monotremes and only a few Marsupials, all of which, with the 

 exception of Caenolestes, belong to the Polyprotodont division of 

 that order, and to a peculiar family, Didelphyidae. The recent 

 discovery of other fossil Marsupials, however, to some extent 

 favours Huxley's view that Neogaea and Notogaea form one 

 realm as opposed to the rest of the world. Besides this, 

 Neogaea possesses the Edentata, which are found nowhere else ; 

 that is, the division of the Edentata to which the name is 

 now restricted by some authorities. It is also characterised by 

 the nearly entire absence of the important order of Insectivora ; 

 and, as minor marks of distinction, by the absence of Antelopes, 

 Oxen and Sheep, of the Ichneumon tribe, of Horses, and of Lemurs. 

 It has the exclusive possession of the Hapalidae and Cebidae, 

 and of several families of Eodents. 



(3) Arctogaea. This vast realm is clearly capable of sub- 

 division into four regions, which will be considered in detail 

 later. In the meantime the points of likeness between these sub- 

 divisions is more marked than are either the resemblances or the 



1 This term is sometimes used in a wider sense ; cf. vol. viii. p. 74. 



