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ORDER PLECTOPTERA. 



(May-Flies.) 



These are delicate little insects with beautiful 

 lace-wings. (Plate ii, Fig. 7.) The hind pair is 

 usually much smaller than the fore pair, and in 

 some species is absent. The mouth parts are rudi- 

 mentary. There are three long thread-like tails at 

 the end of the abdomen. 



The life of the may-fly is very short. Reaumur 

 considers that in some species the adult emerges at 

 dusk and never sees the sun — living but for a 

 few hours. However some species are said to live 

 three or four days. 



The larvae of these insects are aquatic and are 

 well known by those interested in water animals 

 and insects. The habits and life histories of Aus- 

 tralian may-flies are not well-known yet, and we 

 will give a brief outline of the life as recorded else- 

 where. The eggs are laid in water — usually just 

 dropped by the mother, and left to drift in the 

 stream. In another case the mother creeps down 

 into the water and lays her eggs under stones, etc. 



The larva emerges and is fitted for a life in the 

 water, for plate-like gills are gradually developed. 

 These gills may be fringed or may be simply plate- 

 like. In most larvae there are long caudal setae or 



