THE AUSTRALIAN REGION 41 



MwridcV, all of them restricted to the Sub-region. One of 

 these, remarkable for its peculiar and probably prehensile 

 tail, is found only in the mountains of New Guinea, and 

 has been placed in a new genus {Chiuromys). Among the 

 Rodents also there is one very obvious intruder from the 

 west; this is the Javan porcupine (Hystrix javanica), 

 which in this Sub-region is found only in Timor, but is 

 very widely distributed throughout the Oriental Malayan 

 Islands. 



Finally, the Papuan Sub-region, with its luxuriant 

 vegetation and tropical forests, seems to be extremely 

 favourable to the presence of Bats, of which there are 

 more than sixty species known to occur within its limits. 

 More especially is this the case with the large fruit-eating 

 bats of the genus Pteropus, since about twenty out of the 

 forty known species of this genus are found within this Sub- 

 region. This genus {Pteropus) has a remarkable area 

 of distribution, which it is difficult to account for satis- 

 factorily. Its range extends from Madagascar and the 

 neighbouring Mascarene Islands through the Seychelles to 

 India, Ceylon, Burma, and the Malayan Archipelago, and 

 includes even Southern Japan ; thence it is continued over 

 all the Papuan Sub-region into Australia and most of the 

 Polynesian Islands. This genus, it may be noted, seems 

 to have a special propensity to peculiar development in 

 insular areas. Out of about forty species of Pteropus as 

 yet known, only two {Pteropus medius from India, and 

 Pteropus edulis of the Malay Peninsula) are found on the 

 main continental mass ; all the other species are confined 

 to islands, and in many cases to very small limits. For 

 instance, one species (P. livingstonii) is restricted to the 

 Comoro Islands in the Indian Ocean, three others to single 



