60 NORTH AMERICAN DIPTERA 



KEY TO GENERA 



1. Wings with cell 1st M2 present. (Anisopodinse) 2 



Wings with cell 1st M; open by the atrophy of basal section of M3 3 



2. Wing-membrane with macrotrichia (14*; also 1); posterior tibia with a 



comb of spinous setae Anisopus Meigen 



Wing-membrane without macrotrichia; posterior tibia without spinous 

 comb; tropical (2) Olbiogaster Osten Sacken 



3. Wings with vein R3 present as a nearly transverse element, connecting 



with vein R1+2 at margin (15*); eastern (Axymyiinse) . .Axymyia McAtee 

 Wings with vein R3 lost by atrophy, there being only two branches of 

 Rs (16*) ; north temperate (Mycetobiinje) Myeetobia Meigen 



The most important paper: 



Edwards, F. W. 



1928. Diptera. Fam. Protorhyphidse, Anisopodidse, Pachyneurida;, Tri- 

 choceridse. Genera Insectoruni, Fasc. 190, pp. 1-41, 2 pis. 



* Plate II, Tipuloidea. 



