CLASSIFICATION OF INSECTS 



323 



G. Abdomen slender ; wings narrow ; antennae plumose 



in the males. Midges. (Fig. 456) CHIRONOMIDAE 



GG. Abdomen short and thick ; antennae shorter than the 



thorax, nonplumose. 



H. Wings very broad, anterior veins stout, the other 

 weak. The black-flies .... SIMULIIDAE 

 HH. Wings large but more normal in character ; legs 

 strong, front femora often thickened. 



BlBIONIDAE 



SB. Anal closed or distinctly narrowed, second vein never furcate ; antennae 

 usually with three joints, the third joint sometimes complex and com- 

 posed of numerous annuli . BRACHYCERA 



C. Third joint of the antennae with from 4- to 8-segmented annuli. 

 D. Squamae rather large; third joint of the antennae without a 



style or arista. Horse-flies TABANIDAE 



DD. Squamae small or vestigial. 



E. Costal vein does not extend beyond the tip of the wing, 

 longitudinal veins covered anteriorly ; posterior veins often 

 weak; tibiae without spurs. Soldier-flies. (Fig. 457) 



STRATIOMYIDAE 



EE. Costal vein encompasses the wing ; posterior veins strong ; 

 middle tibiae at least with distinct spurs ; antennae extremely 



variable . .- -. LEPTIDAE 



CC. Third joint of antennae simple, not composed of numerous annuli. 

 D. Antennae long, clavate, apparently 4-jointed ; palpi small or 



wanting. Mydas-flies MYDAIDAE 



DD. Antennae 3-jointed, often with a variable style or arista ; palpi 



always present, usually prominent. Robber-flies . ASILIDAE 



E. Antennae apparently 2-jointed ; anterior veins stout, the 



others weak and extending obliquely across the wing. 



Small hunch-backed flies PHORIDAE 



EE. Antennae 2- or 3-jointed ; head small ; squamae very large ; 

 abdomen inflated. Parasitic on spiders . . CYRTIDAE 

 F. Third antennal joint usually with a terminal style, pro- 

 boscis often prominent; body frequently covered with 

 long, delicate hairs. Bee-flies. (Fig. 460) BOMBYLIIDAE 

 FF. Third antennal joint without terminal style ; fourth vein 

 terminates at or before the tip of the wing. Window- 

 flies SCENOPINIDAE 



G. Small, for the most part bright-colored green or blue ; 

 second discal cell confluent with the discal cell ; arista 

 dorsal or terminal. Predacious. DOLICHOPODIDAE 



GG. Small, not brightly colored ; head small, eyes some- 

 times contiguous ; proboscis rigid. Predacious. 



EMPIDIDAE 



