52 NORTH AMERICAN DIPTERA 



111. Wings with vein Cui nearly straight, its distal section not swinging 



cephalad toward wing-tip; cell 1st M; small, less than one-half the 

 distal section of M1+2; terminal three segments of antennae smaller 



than the remainder of flagellum Trimicra Osten Sacken 



Wings with vein Cui having its distal section slightly deflected at 

 apex toward wing-tip; cell 1st M.., when present, elongate, subequal 

 to or longer than the distal section of M1+2; flagellar segments 

 becoming progressively smaller to outer end (44) (Erioptera) 112 



112. Wings with vein 2nd A arcuated so cell 1st A at midlength is as 



broad as, or broader than it is at margin; cell 1st M: opening into 

 cell 2nd M- by atrophy of m; (44); chiefly temperate. 



Erioptera: Erioptera Meigei' 

 Wings with anal veins divergent, cell 1st A being widest at margin; 

 cell 1st M2 generally closed 113 



113. Wings with cell 1st M. open 114 



Wings with cell 1st M2 closed, the basal section of M3 greatly ex- 

 ceeding m in length 115 



114. Wings with cell 1st Mj opening into cell M3 by atrophy of basal sec- 



tion of Ms; where closed, the elements closing outer end not greatly 

 disproportionate in length, m being one-half or more of M3; chiefly 



tropical Erioptera: Mesocyphiona Osten Sacken 



Wings with cell 1st M2 opening into cell 2nd M2 by atrophy of m; 

 northern and western Erioptera: Psiloconopa Zetterstedt 



115. Wings with a spur from the basal section of vein M3, jutting basad 



into cell 1st M2 Erioptera: Hoplolabis Osten Sacken 



Wings with no such spur as described Erioptera: Ilisia Rondani 



SUPPLEMENTARY KEY TO THE SUBAPTEROUS TIPULID^ 



1. Frontal prolongation of head with nasus (Tipulinse) Tipula Linnjeus 



Frontal prolongation of head (or rostrum) without nasus 2 



2. Eyes with numerous short erect setai between ommatidia (Pediciini). 



Tricyphona Zetterstedt 

 Eyes without setae 3 



3. Tibial spurs present. (Hexatomini) Limnophila Macouart 



Tibial spurs lacking. (Eriopteriui) Chionea Dalman 



TYPE SPECIES OF THE NEW GENERA AND SUBGENERA PROPOSED 



Dicranota: Eudicranota; type, Dicranota notabilis Alexander. 

 Dicranota: Paradicranota; type, Dicranota rivularis Osten Sacken. 

 Archilimnophila; type, Limnophila unica Osten Sacken. 

 Limnophila: Idiolimnophila; type, Limnophila emmelina Alexander. 



