BY ROBERT HALL. 325 



There is still the feeblest kind of bridge in the broad 

 tract of southland between Eyre Peninsula and King 

 George's Sound. 



I think when the Diprotodon was being embedded in 

 the pleistocene limestone the conditions were favourable 

 to the passage of those genera now in the south-west, 

 and consequently not favourable to their return. I have 

 collected Diprotodon remains on the southern end of 

 Eyre Peninsula. These are now in the Tasmanian 

 Museum. The disturbances which formed the great 

 valley of South Australia rather dislocated the western 

 emigration course of the most southern birds from area 4. 



According to Professor J. W. Gregory (i) this is of 

 much later age than either the marine clays or desert 

 sandstone of the central plains of area 7. 



The Table I. shows ninety-nine species of Passerine 

 birds found in area 9. Of these, two-thirds are to be 

 found in area 7, as well as two-thirds in area 6, while 

 only one-quarter of them is to be found in area 8. The 

 same table show^s sixty genera. Excepting four genera 

 the whole of these are to be found in area 6, and the 

 whole of the same in area 7, excepting seven genera, 

 while in area 8 there are twenty genera absent. The 

 effect of an intervening desert on a fauna that is not a 

 desert fauna is clearly seen in these western areas. 



Looking at the western line of emigration in the 

 north, we find area i is the first western offshoot of the 

 southern part of the old Papuan sub-region. 



A reference to the relation of species with other areas 

 has been made, as above. Generically the position is a 

 similar one, there being only six of the fifty-four passerine 

 genera absent from area 2. By the time the passerine 

 genera of area i had populated area 8 no less than nine- 

 teen of these genera were found to be absent in area 8. 

 About one-third of the passerine genera of area i is 

 absent from area 7, as follows: — Poephila. Mumia, 

 Neochmia, Calornis, Eopsaltria, Monarcha, Piezorhyn- 

 chus. Arses, Poecilodryas, Oriolus, Sphecotheres, and 

 Chibia. Genera in area i other than passerine, and 



(i) "The Dead Heart of Australia." p. 241 (1909). See Year 

 Book Commonwealth 1910. Geological Map. 



