BY K. J. TILLYaHD. -259 



covery. Fortunately, species of all four genera occur, tliou^^h 

 not commonly, within 100 miles of Sydney. I have, therefore, 

 while not neglecting less interesting forms, paid as much atten- 

 tion as possible to these, and have achieved a fair measure of 

 success wMth them. In the first part of this paper, then, I offer 

 the results of my observations upon that remarkable denizen of 

 the Blue Mountain region, Petalura gigantea. 



The apparent rarity of this huge dragonfly made me almost 

 despair of ever discovering anything about it. During my first four 

 years in Sydney I never saw a single specimen on the wing, though 

 I received on an average about one a year from friends who visited 

 different localities in the Blue Mountains. Mr T. Steel, who has 

 been kind enough to send me from time to time dragonflies from 

 vaiions localities, assured me that he had seen this insect fairly 

 commonly one year in an open sp ice near the Katoomba railway 

 station. This remark put me on the right track. I determined 

 to spend much of my spare time last season in the vicinity of 

 Katoomba For this purpose I selected the small creek running 

 over the Leura Falls, and nearly every Saturday during November 

 and early December, 1908, I made the journey up to Leura and 

 spent all day on the creek. Careful dredging of the weeds and 

 sandy bottom of the clear running stream yielded few larvae of 

 any kind, the creek being little more than a rocky cataract in 

 most places. Working up, however, away from the Falls, the 

 source of tlie stream is reached in little over a mile, and consists 

 of a large teatree swamp, at the head of which there is nothing 

 but vile mud and decaying vegetable matter, of an average depth 

 of one foot or more. On November 21st, 1908, just as I had 

 decided to give up for the day, I found m}^ first pair of Petalura 

 exuviae clinging to grass stems above a small mud hole of filthy 

 mud and water that had clearly been made by a post, since 

 removed. During the weeks that followed, I found many exuvioe, 

 several just transforming, in tlie teatree stems and clumps of 

 sedge in this muddy swamp. The matted s^ems of decayed 

 vegetation made it quite impossible to use the net here to find 

 living larvse; nor was it possible to turn over large quantities of 



