34 THE GEOGRAPHY OF MAMMALS 



are two genera of Rodents (Hydromys and Uromys), and 

 one Bat (Nyctophilus). Seventeen genera which are 

 found in Australia extend beyond the limits of the Region, 

 to the Oriental, and in some cases range even into the 

 Ethiopian and Pakearctic Regions. Of these the greater 

 number (fourteen) are Bats; one is a Marsupial (Phalanger), 

 of which two species occur in Celebes ; another is the 

 widely spread genus Mus, which is found throughout the 

 Old World ; and the last is a Carnivore (Canis), of which 

 the Australian representative is the Dingo. Canis is 

 spread over the whole of the rest of the world, both 

 Old and New. 



Turning now to the distribution of the genera within 

 the continent of Australia itself, it will be found that out 

 of forty-three genera (of Monotremes, Marsupials, and 

 Rodents), twenty are fairly represented throughout the 

 whole area, thirteen are confined to the east (several of 

 these ranging north into New Guinea), seven are re- 

 stricted to the western and central parts of the continent 

 (these latter are chiefly desert forms such as Perogale, 

 Choeropus, and Notoryctes), and the three remaining 

 genera are found only in Tasmania. These are Thylacinus, 

 Dasyurus, and Mastacomys. 



If now Ave reconsider the list, counting only Mono- 

 tremes, Marsupials, and Rodents, it will be found that out 

 of 130 species, thirty-five range from west to east to 

 greater or less extent; forty-nine are confined to the 

 eastern part of Australia, in many cases extending to 

 Tasmania; and thirty-six are peculiar to Western Australia 

 while ten species out of the whole Mammal-fauna are 

 peculiar to Tasmania. 



