VI 



PAGH 



Suborder Cyclorrhapha 175 



Division Acroptera 175 



Division Aschiza . . . . : 175 



Division Schizophora 176 



Characters of the pupa? 177 



Suborder Orthorrhapha 177 



Division Nematocera 177 



Division Brachycera 178 



Suborder Cyclorrhapha 178 



Divisions Acroptera, Aschiza, and Schizophora 178 



Keys to suborders: — 



Larva? 179 



Pupa? 179 



Imagines 180 



Suborder Orthorrhapha 180 



Keys to divisions: — 



Larvag 180 



Pupa? ISO 



Imagines ....". 181 



Division Nematocera 182 



Tabular arrangement of families 182 



Keys to families: — 



Larva? 183 



Pupa? 1S5 



Imagines 188 



Tribe Polyneura 190 



Tipuloidea 190 



Tipulidae 191 



Keys to subfamilies 193 



Ctenophorina? 194 



Tipulinae 195 



Principal papers on North American Tipulida? 206 



Limnobiida? 207 



Keys to subfamilies 208 



Cylindrotomina? 210 



Limnobiina? 212 



Pediciina? 216 



Limnopliilina? 220 



Rhamphidiina? 2H6 



Eriopterina? :li'~ 



Hexatominrc 232 



Trichocerina? , 234 



Papers on the Biology of North American Limnobiida? 238 



Pty'chopteridae 238 



Rhyphida? 241 



