CHAPTER I 



INTRODUCTION 



HISTORICAL. 



In his subdivision of the Class Insecta, Linnaeus placed all the 

 Dragonflies known to him in the single genus Libellula, forming 

 the family Libellulidae of the very heterogeneous Order Neuroptera. 

 His pupil Fabricius, in re-arranging the Orders of Insects by the 

 structure of their mouth-parts, constituted the Dragonflies as a 

 separate Order under the name Odonata 1 , because of the form of 

 their mandibles. His general scheme quickly fell into disuse. But 

 the name Odonata persisted, and has been adopted by all subse- 

 quent writers. Latreille merged the Odonata with the May-flies 

 (Ephemeridae) in his Order Subulicornia, based on the form of the 

 antennae. To these Gerstaecker added the Stone-flies (Perlidae) 

 forming a group Orthoptera Amphibiotica, characterized by the 

 possession of aquatic larvae. Erichson, in splitting up the old 

 Order Neuroptera, formed an Order Pseudoneuroptera to comprise 

 the Odonata, Ephemeridae, Psocidae and Termitidae. Later 

 workers have almost unanimously rejected these unnatural 

 groupings, and have regarded the Odonata as a distinct Order. 

 The name Paraneuroptera has been suggested by Dr Shipley as 

 a substitute for Odonata, with a view to maintaining the termina- 

 tion "-ptera" for all Orders of Winged Insects. 



Recent work on the morphology and phylogeny of the Dragon- 

 flies has not only tended more and more to confirm the view that 

 they form a distinct Order of Insects, but has even gone so far as 

 to increase our sense of their isolation. Thus Handlirsch [67], on 



1 Greek 68ovs a tooth, stem 65<W-. The word should therefore more correctly 

 be Odontata. 



