X PREFACE 



who know how rich and varied the Australian Dragonfly-fauna is, 

 will look upon this rather as an advantage than otherwise. While 

 care has been exercised in selecting, for general description, well- 

 known genera of wide distribution, yet there has been no hesitation 

 in making use of the more archaic Australian forms, when these 

 latter could throw new light on the phylogeny of the Order. 



Throughout the book, the names Gomphus, Aeschna, Calopteryx 

 and Agrion are used in the Selysian sense. In common with 

 practically all other students of the Order, I regard these names 

 as nomina conservanda. Their alteration would not only lead 

 to immense confusion, but would in a sense vitiate the whole of 

 the classical or Selysian literature. Odonatologists are more 

 concerned than anyone else in the retention of these names, and 

 they will never consent to their arbitrary removal by committees 

 formed of men who know little, and care less, about the require- 

 ments of this very special branch of entomology. 



The MS. of this book was completed on March 19th, 1915, and 

 was forwarded to Cambridge in July, 1915, with the Bibliography 

 brought up to that date. During the first correcting of proofs, 

 opportunity was taken to bring the work on the Respiratory 

 System (Chapter IX) into line with the recent researches of Calvert 

 and myself; but it was not considered practicable to add any 

 new records to the Census and lists of genera. The Additional 

 Bibliography on p. 373 was added in July, 1916, when the first 

 proofs were returned to Cambridge. The sending of the original 

 MS., figures and plates, three sets of galley-proofs and three sets 

 of page-proofs (involving in all a total of some fifty packets and 

 letters), to and fro between England and Australia in these 

 troublous times, without the loss of a single item, is an achieve- 

 ment which I cannot let pass without offering my grateful thanks 

 to all who were responsible for it. 



In conclusion, I desire to acknowledge with very sincere 

 thanks the help received in the preparation of this work. My 



