FUNGUS GNATS OP NORTH AMERICA. 255 



h. Intermediate antennal joints closely sessile ; an- 

 nular or torus like ; tibiae stout, noticeably en- 

 larged at the ends, the setae moderate ; base of 

 fork of the cubitus proximad of the proximal 

 y^^ end of the R-M crossvein ; subcostal vein end- 



ing in Ri; wing sometimes with markings. 

 (Fig. 229). 21. Brachypesa. 



hh. Antennal joints usually subcylindrical ; and other- 

 wise not with the above combination of charac- 

 ters; wings unmarked except in Telmaphihis. 

 i. Cubitus forks proximad of the fork of the media, 

 j. Anal vein very stout and ends abruptly, usual- 

 ly a little beyond the fork of the cubitus, 

 angle between the branches of cubitus very 

 acute at the base, the lower branch beyond 

 its middle suddenly diverging from the up- 

 per branch, base of fork at or proximad of 

 proximal end of the R-M crossvein. (Fig. 

 230). ^ 22. Rhyinosia. 



'}'}. Anal vein slender (Fig. 238) (including 

 Brachycampta). 23. Allodia. 



ii. Cubitus forks distad of the fork of the media, 

 j. The media forks distad of the end of the 

 basal cell R : costa extends very little be- 

 yond end of the radial sector ; ocelli 3, 

 middle one very small, 

 k. Wings hyaline; subcosta less than i length 

 of basal cell. 24. Phronia. 



kk. Apex of wings more or less clouded or 

 smoky; subcosta end free beyond middle 

 of basal cell. 25. Tehnaphilus. I 



]]. The media forks proximad of tlic end of the 

 basal cell R, the subcosta ends free; middle 

 ocellus present or absent. (Fig. 242). 



'' 26. Exechia. 



gg. Posterior basal seta of hind coxa absent; the ranges 



of seta; on the hind tibiae conspicuously stout, setae 



at least twice as long as the diameter of the tibiae; 



crossvein usually with dark spots, wing often 



fasciate. 



h. Subcostal vein ends in Ri, branches of the cubitus 



noticeably divergent; usually three ranges of 



setre on bird tibiae; middle ocellus usually 



absent. 27. Dynatosoiiia. 



hh. Subcostal vein ends free. 



i. Hy.popygium of the male conspicuously large 

 and husk like; female with a fringe of long 

 setfe on ventral side of sixth abdominal seg- 

 ment; middle ocellus present; branches lof 

 cubitus subparallel at end. 28. Opistholoba 



