NORTH AMKRICAN ODONATA. 153 



IP^K.T I. 



A GENERAL ACCOUNT OF THE ODONATA. 



Names and Definition. 



The insects technically known as the Odonata have received the 

 popular English names of Dragonflies, Darning-needles, Bad-man's- 

 needles, Devil's darning-needles, Snake doctors. Mosquito hawks and 

 Horse-stingers. Some of these names testify to that widespread, but 

 quite unfounded belief in the harmfulness of these creatures to man, 

 which is by no means yet extinct. 



Philip Andreas Nemnich, in his Allgemeines Polyglotten-Lexicon der Natur- 

 geschichte, article Libellula, has brought together many popular names of the 

 dragonfly in various languages, especially from the German. A selection is 

 added: German, Wassernympfe, Wasserjungfer (water maiden); French, demoi- 

 selle; Spanish, Nadadora ; Portugese, Mosca qne da grandes picadas (fly with the 

 great stings) ; Italian. Cevettone, Saetta (arrow) ; Dutch, Juffer, Scherpstel-endevUeg 

 (sharp-sticking-fly) (McLachlan) ; Danish, Guldsmed ; Swedish, Trollslanda. 



In the classification of Linnaeus, the dragonflies appear as the 

 genus Libellula of the order Neuroptera. Fabricius was the first to 

 apply to them the name Odonata* (Eut. Syst. ii, p. vi, 373, 1793), 

 to designate his fifth ' Classis' of the Insecta. Subsequent writers 

 have variously regarded the group as a family or as a suborder, 

 either of the Neuroptera or of the Pseudoneuroptera, retaining the 

 Fabrician name. Still other, and for the most part later authors 

 regard the Odonata as an order of the Ametabolous, Hemiuietabo- 

 lous or Homonjorphous series of Insects. 



The zoological characters of the Odonata are : 



Insects with an incomplete metamorphosis. Alimentary canal 

 Avithout c?eca. Seven pairs of abdominal ganglia. Malj^ighian 

 tubules numerous (50-70). 



Imago. — Head of conspicuous size, its prothoracic articulation 

 very mobile ; antennae short, awl-like (subulate) ; eyes large ; three 

 ocelli ; biting mouth-parts, labium proportionately large. Prothorax 



* Greek 'OSous, oSovtos (odous, odontos), a tooth, referring presumably to the 

 toothed mandibles. 



TRANS. AM. ENT. SOC. XX. (20) JULY, 1893. 



