Phi/siofjrd/t/t 1/ of Y(irra, etc. 473 



Creeks, whose valleys are broad open ones, due to the com- 

 paratively slight elevation of the country above sea-level, and 

 the mature state of the Yarra where these streams junction. 

 Farther east, the Mullum-Mullum, Anderson's, and Narrmeian 

 Creeks possess narrow, deep valleys, consistent with the Yarra 

 itself at their various points of entrance. The five tributaries 

 just mentioned all have accordant junctions, and are all essen- 

 tially Silurian streams. 



The next valley to the east, that of the Brushy Creek, offers 

 a striking contrast to its immediate neighbours, the Narr- 

 meian. Anderson's and Mullum Mullum Creeks. The Brushy 

 Creek valley is a broad, open, flat-bottomed one, with a slug- 

 gish stream meandering through its own alluvium, while fur- 

 ther east the streaaiis running in a northerly direction towai^ds 

 the Yarra, such as the Olinda Creek and other small water- 

 courses in the parish of Yering, do not reach the Yarra, but 

 lose themselves in the broad, marshy flats bordering the 

 Upper Yarra. The valleys of these streams before entering the 

 flats are bounded by low hills with gently sloping sides. 



Beyond the flats again to the east, another nest of closely 

 related streams occurs, including the Woori Yallock Creek, 

 Hoddle's Creek, and the Little Yarra. These are fairly well 

 developed, chiefly in silurian country, and possess the normal 

 characteristics already noted of other similar streams. 



At Warburton, as above remarked, mountain torrents exist 

 on both sides of the river. 



Farther to the east again, the southern tributaries appear 

 to be generally similar to those entering from the northern 

 side, and are chiefly in silurian country. 



The basin of the Dandenong Creek oft'ers in several respects 

 a marked contrast to that of the Yarra. The latter is much 

 larger than the former, which is generally at a low elevation, 

 and is fed by ground of little height, with the exception of 

 some drainage from the Dandenong Mountains. The result is 

 that the main stream^ — the Dandenong Creek — is very small, 

 and its tributaries, with the exception of the Blind and Cor- 

 hanwarrabul Creeks, are quite insignificant. A further result 

 is that the valleys are generally wide, shallow and tending 

 to flat Ijottoms, with alluvial flats. These characteristics are 



