10 Families and Genera of 



4. A complete diseal cell present; ocelli present; empoflia devel- 

 oped pulvilliform, pulvilli rudimentary. RhyphidjE 

 No discal cell 5 



5. Wings with only a few longitudinal veins, and i^ cross-veins ; 



coxae not elongate, tibia; without terminal spurs, legs not thick- 

 ened; ocelli present or absent; small or minute, delicate, 

 mostly gall-proilucing flies. . . . Cecidomyid>e 



Not suL'h flies, wings usually many-veined. ... 6 



6. Ocelli present. 7 



Ocelli wanting (compare My ce tophi lidae.) . 9 



7. Wings broad, bare, characteristically marked by numerous folds 



between the veins, giving a netted, spiderweb-like appear- 

 ance Blepiiauocerid.e 



Wings not so marked ; no entire transverse suture. . 8 



8. Coxae much elongated (moderately so in Sciarinae); antennae 



often elongate, the joints constricted; three or two oaelli (in 

 the latter case situated near the eyes, and often hardly per- 

 ceptible); all the tibiae with spurs. . Mvcetophilid.e 

 Coxae short, the thorax rounded, not humped, above ; antennae 

 shorter than the thorax, thickened, the joints closely united 

 without marked constrictions; legs strong, the front femora 

 often thickened ; empoiia pulvilliform, the pulvilli sometimes 

 absent; eyes of male large. ... Bibionid.e 



9. The costal or marginal vein does not extend beyond the tip of 



the wing. ......... 10 



The marginal vein encompasses the entire wing. . . • . 11 



10. Antennae slender, the joints more or less constricted, and often 



bushy plum:)se; legs slenier, hinl tibiae and metatarsi never 

 dilated; body and abdomen slender; wings narrow. 



ClIIRONOMID^E 



Antennae shorter than the thorax, the joints broadly and closely 

 united, without marked constrictions, and never hairy or pi- 

 lose; legs strong, hind pair mjre or less dilated; body thick- 

 set, abdomen ovate ; wings broad, bare, the anterior veins 

 stouter, the posterior ones weak. Black-flies, buffalo-gnats. 



SiMULIDiE 



11. Wings distally, with ten longitudinal veins, without cross-veins, 



broad, pointed, veins strongly hairy ; tibiae without terminal 

 spurs; small, lepidoptera-like flies, the wings, when at rest, 

 folded roof-shaped. Psychodid.*: 



