89 



7. First submarginal cell short, not more than half the length of the 



second. ... ...... 8 



First submarginal cell more than half the length of the second, n 



8. Marginal cross-vein present. ....... 9 



Marginal cross-vein absent (7) Goniomyia. 



9. Second submarginal cell in contact with the discal cell, the ante- 



rior cross-vein obsolete. . . . . . . .10 



Anterior cross-vein present, the first posterior cell intervening be- 

 tween the submarginal and the discal cells. . Empeda. 



10. Seventh longitudinal vein very short; no empodia (26). 



Mongoma. 



Seventh longitudinal vein not unusually short; empodia present. 



Paratropesa. 



u. Seventh longitudinal vein conspicuously bisinuate (21). Helobia. 

 Seventh longitudinal vein straight. . . . . . 12 



12. Length of the auxiliary vein beyond the cross-vein at least twice 

 that of the posterior or great cross-vein (8) . . Trimicra. 

 The cross-vein situated near the end of the auxiliary vein (1O) . 



Gnophomyia. 



UMNOPHIUNI. 



1. Discal cell open; antennae apparently 2S-jointed in the $ (28). 



Polmera. 

 Discal cell closed. ......... 2 



2. Marginal cross- vein wanting. .... Phyllolabis. 

 Marginal cross-vein present. ....... 3 



3. Wings pubescent, Ulomorpha. 



Wings bare. .......... 4 



4. Seventh vein very short, abruptly incurved toward the anal angle 



(5) Trichocera. 



Seventh vein not unusual. ....... 5 



5. A supernumerary cross-vein between the auxiliary vein and the 



costa (p. 80, 5) Epiphragma. 



No such .supernumerary cross-vein (1, 9, 19)*. Limnophila. 



* A wingless form has recently been referred to this genus, with 

 doubt, by Mr. Coquillett. 



