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THE POPULAR SCIENCE MONTHLY 



Bridal Veil Falls, Gavett's Leap, in the Blue Mountains of New South Wales, show- 

 ing the characteristic block faulting seen along this part of the Australian coast. 



There are, however, parts of the Great Barrier Eeef region which 

 are afflicted periodically by hurricanes and the reefs in these regions 

 consist of large coral heads quite far apart instead of great numbers 

 of small ones close together. Moreover, the pure ocean water of the 

 Murray Islands is fairly free from silt, whereas that of Thursday Island 

 bears a vast amount of mud in suspension and this, also, is fatal to corals 

 and buries the small heads more readily than the large, and thus the 

 reefs of Thursday Island are not rich, but the coral heads are of large 

 size and are widely separated. 



It is interesting to see how the 40 or more species of corals that grow 



