122 STEPS IN SPECIALIZATION 



E. The most characteristic method of reduction of the wing-veins 

 of the preanal area being by coalescence outward. 

 F. Anal veins of the fore wings tending to coalesce at the tip. 



Wings usually clothed with hairs Trichoptera 



FF. Anal veins of the fore wings not tending to coalesce at the 

 tip. Wings clothed with scales Lepidoptera 



EE. The most characteristic method of reduction of the wing- 

 veins of the preanal area being by coalescence from the margin 

 of the wing inward. 



F. With only one pair of wings Diptera 



FF. With two pairs of wings Hymenoptera 



LIST OF ORDERS 



Orthoptera 



Isoptera 



Neuroptera 



Ephemerida 



Odonata 



Plecoptera 



Corrodentia 



Embiidina 



Thysanoptera 



Homoptera 



Heteroptera 



Dermaptera 



Coleoptera 



Strepsiptera 



Mecoptera 



Trichoptera 



Lepidoptera 



Diptfera 



Hymenoptera 



