THE ANIMAL KINGDOM. 



here and elsewhere need not claim our attention, the only Mammals except 

 Marsupials and Monotremes are a certain number of Rodents belonging to 

 the family Muridce, and the Australian wild dog, or dingo. New Guinea, on 

 the other hand, possesses a pig, which may possibly, however, have been 

 introduced. 



When Celebes and the other Austro-Malayan islands are reached, Mono- 

 tremes are absent, and Marsupials form only a small moiety in the fauna. 

 This realm is the sole home, not only of the Monotremes, but likewise of the 

 typical Diprotodont Marsupials, 1 while the only other part of the world where 

 Marsupials are now found is America, where they are represented among other 

 forms by the opossums, which are quite unknown in Australia. As Marsupials 

 of extinct types inhabited the Northern Hemisphere during earlier epochs, it 

 is evident that the Notogseic realm received its Marsupial and Monotremes 

 fauna at a date when such creatures were the dominant forms in South-Eastern 

 Asia, which was then populated by but few other types of Mammalian life. 

 When these ancestral Marsupials and Monotremes had effected an entrance 

 into Australia and New Guinea, with the adjacent islands, they became more 

 or less completely cut off from the rest of the world, and were enabled to 

 develop apart from the competition of the higher forms of life. It is note- 

 worthy that some of the Australian Rodents present a marked similarity to 

 these of the Philippines, showing that the immigration has been from the 

 northward. Notogsea may be divided into several regions. One of these is 

 the New Zealand region, characterised by the absence of all terrestrial 

 Mammals, and the abundance of flightless birds, nearly all of which are now 

 extinct. Under the title of the Australian region may be included Australia, 

 Tasmania, New Guinea, the Am Islands, New Caledonia, New Britain, etc. ; 

 this region being characterised by the preponderance of Marsupials and the 

 presence of Monotremes. The Austro-Malayan region, which includes the 

 islands mentioned above, has, on the other hand, only a small number of 

 Marsupials among a preponderance of Placentals, so that this region forms a 

 transition between Notogsea and Arctogsea. 



Nearly as distinct from the rest of the world as the last, is the Neogaeic 

 realm, comprising South and Central America, together with the West 

 Indian Islands. Now, however, the distinction of this realm, as a primary 

 region, is much obscured by the union of South with North America, which 

 has allowed many essentially Northern types to migrate into South America, 

 while a certain number of Southern forms have penetrated into the Northern 

 half of the continent. There is evidence that during the Cretaceous Period, 

 or latest division of the Secondary Epoch, what is now Mexico was a sea, while 

 in the Middle, or Miocene division of the Tertiary Epoch, the same was the 

 case with Central America. It is thus evident that at two distinct periods, 

 North and South America were disconnected ; although it is quite possible 

 that during some other part of the Tertiary Period antecedent to the Miocene, 

 there may have been a temporary connection either by way of the Isthmus of 

 Darien, or by Florida and the West Indies. At the present day the Neogseic 

 realm is practically the sole home of the Edentates, 2 of the New World 

 monkeys (Cebidce) and marmosets (Hapcdidce), as well as of many peculiar 

 types of Hystricomorphous Rodents, such as the viscacha (Lagostomiis), coypu 

 (Myopotamus), carpincho (Hydroclicerus), cavies (C'avia), agutis (Daryprocta), 



1 This and other terms are fully explained in the sequel. 

 * A few of these and other groups range into Texas. 



