PHYSIOGRAPHY OF . I f 'STR. I/.. IS/, l. 



'35' 



SOME NEW ZEALAND 1IIKDS. 



Australian fauna and flora. Meanwhile, the eastern division had not remained thus 



isolated ; but had been connected with New Guinea, and, indirectly, with a mass of land 



represented in modern times only by New Zealand, 



but at that time much more extensive, and probably 



having temporary and indirect relationships with South 



America. Eastern Australia had in this way received 



accessions of plants and animals from other regions, 



and thus, though some of the peculiar Australian 



families may have been evolved in this region from 



the primitive secondary forms, yet it is reasonable to 



suppose that, in the presence of invading forms 



from without, the primitive animals and plants 



originally, perhaps, less abundant than in the west 



flourished less than there, and perhaps in many 



instances became extinct. The union subsequently, 



in the tertiary or early quarternary periods of the 



eastern and western divisions, brought about a con- 

 dition of things from which the modern fauna and 



flora have been derived. Tasmania became separated 



from the main-land of Australia, and the connection with New Guinea was broken off ; 



New Zealand its connection with Eastern Australia being lost long before attained its 



present restricted size, and isolated position, by the submergence of the mass of land of 



which it previously formed but a relatively insignificant portion. 



The special features of the present Australian fauna, as regards the Vertebrate or 



Back-boned Class, which can alone be touched upon here, have been well summarized 



by Wallace in his " Geographical Distribution of Animals." The chief peculiarities of the 



Mammalia may be briefly stated as follows : The 

 mammals are represented in the Australian fauna 

 almost exclusively by the marsupials an order 

 represented in other regions only in America, and 

 there only by one family. In addition, the Australian 

 region is characterized by the presence of a remark- 

 able order of mammals the Monotremes the lowest 

 of the class, and not represented in any other 

 part of the world. The remainder of the indig- 

 enous mammals are very few, comprising only a few 

 bats and flying-foxes, a limited number of species 

 of rats and mice, and the Dingo or native dog. 



The marsupials, then, are the characteristic 

 Australian mammals. For though, as remarked 

 above, marsupials are not entirely confined to the 

 Australian region there being one family of marsu- 

 pials, the Didclphidcr, or American opossums, inhabit- 

 ing America yet they reach here by far their greatest development in numbers and 



THE WOMIiAT AND THE PLATYPUS. 



