30 THE NOTOGyEIC REALM. [CHAP. 



are restricted to Australia, with Tasmania ; and New Guinea, with 

 the adjacent islands, such as the Aru group. 



The Notogaeic realm, as denned above, may be conveniently 

 divided into four distinct regions, as follows. Firstly the Australian 

 region, comprising Australia, Tasmania, New Guinea and the adja- 

 cent Papuan islands; characterised by marsupials and monotremes 

 forming by far the predominant element in the mammalian fauna. 

 Secondly the Austro-Malayan region, embracing Lombok, Celebes 

 and the other islands lying between them and the Australian region; 

 this area being characterised by the absence of monotremes and by 

 the marsupials (all of which belong to the diprotodont division of 

 the order) forming only a small minority of the mammalian fauna. 

 Thirdly, there is the Hawaiian region, including only the Sandwich 

 Islands; and, lastly, the Polynesian region, which maybe taken to 

 include all the islands, save those last named, lying to the eastward 

 of the Coral Sea, together with New Zealand, and is characterised 

 by the general absence of terrestrial mammals. There is some 

 difficulty in deciding whether the islands of the Solomon group 

 should be included in this region, or classed with the Papuan 

 division of the Australian region, seeing that, in addition to a 

 considerable number of bats, they have four species of mice, and 

 one diprotodont marsupial (Phalanger) 1 . When, however, the 

 poverty of this fauna as compared with that of Papua is taken 

 into consideration, and it is also borne in mind that Mr C. Hedley 2 

 has come to the conclusion that the Solomon Islands, together 

 with the New Hebrides, New Caledonia, Fiji, and Norfolk Island, 

 are closely connected by means of their flora with New Zealand, 

 and have but little in common with Australia and New Guinea, it 

 seems preferable to include the former group in the Polynesian 

 region. On the same grounds, New Zealand is regarded, in 

 accordance with the views of Heilprin, as also forming a portion 

 of the same zoological region, and not as the representative of a 

 separate region by itself. The fauna of the Solomon Islands has 

 doubtless been derived directly from that of the Duke of York 

 group, which clearly belongs to the same region as New Guinea, 

 and shows a much more strongly marked Papuan facies, having 

 three species of mice, and four marsupials. 



1 See Thomas, Appendix, No. 30. 2 Appendix, No. 16. 



