INTRODUCTION 



THE zoogeography of Australia, for all practical 

 purposes, comes under two heads. It has a 

 fauna on the northern and eastern coasts in con- 

 junction, or it extends over the greater portion of 

 the continent. The climatic conditions are so 

 slightly variable, yet so many, as to make innumer- 

 able races. 



There is the coastal zone map 1, 1 — 5, 6, 8, 9, 

 with clearly marked species, while within two 

 hundred miles of the coast these species begin to 

 change in shade of colour, and show a collateral 

 zone (7* — 7®). It is the action of a dry hot 

 atmosphere on them and their surroundings, giving 

 an inner circle of bird life; a ring of races. 



This second continuous band fuses with — and is 

 parent to the lessened life of Central Australia. 

 The outer ring 1 — 6, 8, 9, so far as most of its land 

 forms are concerned, appears to have begun its 

 existence in area 3, on receipt of its early life from 

 New Guinea. Its extension went outwards 2 to 

 1, and 2 to 8. From 4 the birds gradually travelled 

 to 5 and to 9. 



