BY T. GRIFFITH TAYLOR. 



521 



present Blue Mountain Divide did not deflect to any great extent 

 the course of many of the rivers. I refer to the Nattai gorge 



Fig.2. — Geological sketch map of the Great Permo-Carboniferous Geo- 

 syncline of New South Wales. The older Palceozoic rocks are hatched 

 diagonally, the Goal Measures are not hatched. The later Triassic Hawkes- 

 bwif Ssries is hatched with horizontal lines. The figure shows the peripheral 

 expose 1 portions of the Coal Measures in which the chief phenomena 

 discussed in the paper have occurred. 



at Mittagong, where the stream leaves the broad triangular 



valley in which Mittagong is situated, and abruptly flows into a 



37 



