31 8 THE DISTRIBUTION OP AUSTRALIAN LAND-BIRDS. 



From the same data I find that area 8 received its 

 present genera and most of its species from area i, which 

 in its earHer turn received its forms from area 2. That is 

 the northerly Hne of westerly emigration. 



In considering the distribution of the present races of 

 the genera, it would appear very much as if Western 

 Australia had drawn its avifauna from Eastern Australia. 

 Lacustroica (i) is the only genus peculiar to 9, v/hile area 

 8 has only one genus pecuHar to it. Of Lacustroica there 

 are no external characters that lead one to see in it a 

 remaining form of an old fauna, and there is nothing on 

 the whole face of the avifauna of Western Australia to 

 indicate a western origin. 



Neither does the indication point to an Eyrean origin 

 in so far as genera are concerned. There is in area 7 not 

 a genus peculiar to it, all being eastern and south-eastern 

 genera. 



What the avifauna of 7 was like when the Thylacine 

 wandered about Lake Eyre I am not prepared to say, 

 except that I believe it originally came from the north- 

 east of the continent. 



It is the " dead heart " of Australia that has passed on 

 to area 9 the present fauna, assisted by area 6, portions of 

 which evidently have passed through the same trouble- 

 some period. 



The inferences drawn show the gradual blending of 

 the areas i — 9, directly or indirectly, into area 2, or less 

 remotely into areas 2 and 3 combined. 



We know that many of the Australian passerine 

 genera are also represented in other zoological regions — 

 the Zosteropidae, Dicasid^, etc. (2). 



A knowledge 01 the expansion of their areas would 

 be interesting. Zosterops, from an Australian point of 

 view, has four much deflected radii from the Papuan sub- 

 region— (a) the northern coast of Australia; (b) the 

 eastern coast of Australia, altering its course in area 4 to- 

 pass into area 9; (c) Japan via China; (d) South Africa 

 via the horn of Africa and India. The distribution of." 

 each radius, broadly speaking, is a continental fringe. 



(i) Emu. vol. ix., pi. 15 (igjo). 



(2) A.A.A.Sc, Brisbane (1909), pi. p. 748. 



