vi Preface. 



As many as possible of the full-grown nymphs have 

 been described, and one at least of each sub-family 

 has been figured. There are still, however, several 

 species almost or quite unknown in the earlier stages. 

 For the description of six nymphs, and figures of two, 

 I am indebted to Mr. L. Cabot's papers on the 

 " Immature State of the Odonata," contained in the 

 Memoirs of the Museum of Comparative Zoology, at 

 Harvard College, U.S.A., and for them I desire to 

 express my obligation. 



So far as the Synonym}' is concerned, reference has 

 been made to all such authors as are likely to be 

 consulted by ordinary readers, and, in addition, to such 

 others as were found responsible for any of the 

 Synonyms. In connection with the descriptions it may 

 be well to state that those points which are similar in 

 both sexes have been omitted in the case of the female. 

 In all Dragonflies a knowledge of the immature, or 

 teneral, condition is important, but, unfortunately, details 

 concerning it are not often obtainable or, in many 

 instances, easily observed. In this we have another 

 important branch of the subject which requires more 

 extended investigation. The reputed species have 

 designedly been relegated very much to the back- 

 ground, their claims to being considered British being 

 so slender. In attempting to popularise the subject 

 with a view to increasing the number of workers in the 

 same field, it is hoped that no sacrifice of the purely 

 scientific side has been made. 



I wish to record my indebtedness to the many 

 entomologists who have so ungrudgingly given me 

 the benefit of their experience. Notes of occurrences, 



