538 DEVELOPMENT OF THE N.O. MYRTACE^, 



During this period, the continent appears to have been co-exten- 

 sive with New Guinea and Tasmania, and to have extended for a 

 considerable distance southward of Tasmania. 



In late Tertiary time, Eastern Australia was affected by a topo- 

 graphical revolution, during which, the low-lying land, near the 

 sea, was disturbed and raised to form the plateaus of New Guinea, 

 Queensland, New South Wales, Tasmania, and South Australia, 

 as also that of Western Australia. The climate thereby became 

 changed. 



The central plains of Eastern Australia, which had been initi- 

 ally formed in the earlier and middle Tertiary, were much enlarged 

 by the late Tertiary sedimentation, following upon the uplift. 



In the Pleistocene came the general lowering of temperature 

 over the whole world, and withit, the gradual desiccation of Central 

 Australia, as is evidenced by the present process of the choking-up 

 of the old stream-channels with waste. This may be seen well in 

 such districts as that of Cobar. 



The Geographical Distribution of Myrtace^e. 



The authorities consulted in this connection were Index Kewen- 

 sis and the three Supplements thereto. For the Australian distri- 

 bution of Myrtacese, von Mueller's Census for 1889 was used, as 

 also Bentham's Flora Australiensis. With a very few exceptions, 

 the terminology employed is that adopted in the Flora Australien- 

 sis(1866). 



For the purposes of the accompanying lists of species, Jambosa 

 and Syzygium are considered as included under Eugenia, as sug- 

 gested by Bentham and Hooker. Lecythidese is considered as a 

 separate family, the reasons being assigned in a subsequent chap- 

 ter. 



Mr. Cambage has supplied the list of Eucalypts known in 

 Eastern Australia, and Mr. Cheel the distribution in Australia of 

 Callistemon. 



All the other lists are only approximate. 



