186 Annals Entomological Society of America [Vol. XI, 



to the arista. Occiput often with a poUinose band on the lower 

 orbits including the cheeks excepting their lower margin, 

 usually with sparse short hairs, typically a pair of ocellar and 

 one of vertical bristles present, rarely two or three pairs of 

 vertical and an additional pair of post-vertical bristles present, 

 sometimes an oral bristle on the back part of the cheeks. 



Thorax robust, polished, nearly bare to pubescent, dorso- 

 central bristles usually limited to a pair of prescutellars, humeral 

 and posthumeral bristles present or absent, notopleural bristles 

 present but variable, scutellum with two or four marginal 

 bristles, the lateral ones always shorter; pleurae bare, rarely 

 with pollinose streaks following the sutures. Abdomen with 

 eight segments, the first segment laterally inflated, the fourth 

 segment usually large and more heavily chitinized than the 

 others, its sides often pollinose and bearing scimiter-shaped, 

 glistening setulas, the fifth segment short; pygidium varying 

 from small to large, closed to widely open, asymmetrical, the 

 right side usually with a broad, curved, furcate valve. Legs 

 rather stout, the front femora a little the strongest, usually the 

 anterior femora with a basal flexor hair and with a preapical 

 bristle on the outer side, the hind femora with one to three 

 preapical bristles on the anterior face, hind tibiae with extensor 

 bristles and more or less produced as an apical tooth-like spur, 

 the anterior tibiae with a pair of apical bristles; sometimes the 

 legs are devoid of all bristles; pulvilli broad; in those species 

 with broad tibial spur the inside of the hind metatarsi and of 

 the end of the hind tibiae spongy pubescent. 



Wings with anal angle more or less developed, except very 

 rarely the first basal cell shorter than the second which is 

 always fused with the discal cell, five simple longitudinal veins, 

 anal cell completely wanting, at most a short trace of the anal 

 vein present toward the hind margin but the anal cross-vein 

 always lacking, usually the entire margin of the wing uniformly 

 short-ciliate, sometimes the hairs of the first section of the costa 

 are longer, no stigma and no definite color pattern. 



The species of Drapetis are included in the following 

 subgenera : 



1. Drapetis Meigen, sens. str. Type species, exilis Meigen. Rather 

 small, bristleless, black species, with short antennae directed somewhat 

 upward, the second joint without a conspicuous seta beneath, the third 

 joint oval, with long, subterminal arista; legs without strong bristles. 



