16 presibent's address. 



large river conducts the rain-fall to another coast. Europe, 

 Asia, Africa and the larger islands all belong to the first 

 class, while examples of the second are to be found in the 

 Americas and Australia. 



Professor Gregory writes*: "The whole of the noi'thern, 

 western and southern coasts of the [Australian] continent 

 are, to use Professor Suess' term, of the 'Atlantic type.' The 

 eastern coast of Queensland and New South Wales and 

 apparently the eastern coast of Tasmania, are a variety of 



the Pacific type in which the motmtains and the 



trend of the rocks are parallel to the shore .... The eastern 

 coast of Australia is, however, a less normal representative 

 of the Pacific type than is the western coast of America." 



So that in Australia where the Atlantic type of coast 

 occurs there is radial drainage, biit where the Pacific type 

 prevails there is marginal drainage. In some districts the 

 drainage is more intensely marginal than in others. This 

 variation is associated with variation in the submai'ine con- 

 tour opposite each. Where the continental shelf is broadest, 

 there the rivers reach the deepest into the land, conversely 

 the narrowest shelf fronts the shallowest watershed. 



The greatest development of the continental shelf in 

 Eastern Australia is attained about the tropic of Capricorn, 

 there it extends for a breadth of eighty miles. This I regard 

 as a fragment left of a wide shelf which formerly continued 

 along the whole coast, but which in the south has been de- 

 stroyed by the Thomson Deep and in the north by the Car- 

 penter Deep. Sir J. Hector inferred, "That an extensive 

 terrigenous shelf must indicate a long continued period of 

 stability."! The tooth print of destruction is plain on the 

 gnawed border of this continental shelf. 



A great bight occurs between Eraser's Island and Swain's 

 Reef. A very remarkable instance of the recent retreat of 



Gregor}', "Compendium of (Geography," Australia i., 1907, p 85. 

 t Hector, Rep. Aust. A.s.soc. Adv. 8ci. vii., 1898, p.67U. 



