1918] Dipterous Genus Drapetis Meigen 189 



18. Hind tibiae without extensor bristles; second, third and fourth .sections of 



the costa, 2.5:1.6:1, middle segments of the abdomen with flat glisten- 

 ing setulse; base and apex of the front femora, front tibias and base of 



the front tarsi yellow; palpi yellow lata Coquillett 



Hind tibiae with a strong extensor bristle near the middle, legs uniformly 



brownish; costal sections, 1.6:1:8:1; palpi blackish. , .^/jec/a&j/u Melander 



19. Middle tibiae with a long extensor bristle at the basal third, hind tibiae 



with a bristle above and one below the middle, hind femora with a 

 preapical extensor bristle and with three preapical bristles on the 

 front side; five dorsocentrals; pygidium large; hairs of the mesonotum 



black, of the legs long and blackish medelera Melander 



Middle tibiae without an extensor bristle, hind femora without extensor 

 bristles, hind metatarsi not setulose; pygidium smaller 20. 



20. Hind tibiae without extensor bristles; antennas .short, the third joint ovate; 



veins coarse and brown or black 21. 



Hind tibiae with two short extensor bristles located at the middle and 

 near the end; antennae elongate, the third joint lanceolate; veins not 

 coarse and unusually pale 22. 



21. Hind femora d^ with a strong swelling beyond the middle bulging out the 



anterior side; vertex broadly polished; basal section of the fifth vein 



slightly longer than the evanescent outer section; legs brown 



cedimera, n. sp. 

 Hind femora not bearing an abnormal swelling; vertex subshining, the 

 occiput cinereous, the front and lower orbits white pruinose; sections 

 of the fifth vein subequal; legs mostly black parvicornis, n. sp. 



22. Front femora 6^ with a bunch of six black setulae in the middle of the 



upper side, represented in the 9 by one or two; no dorsocentrals, 

 dorsum of cT nearly glabrous, of 9 with white hairs; one preapical 



bristle on the front edge of the hind femora armata, n. sp. 



Front femora not setulose, two preapical bristles on the front edge of the 

 hind femora; five dorsocentrals scissa, n. sp. 



23. Thorax black 24. 



Yellow or reddish species; second joint of the antennae without a seta 



beneath 41. 



24. Under side of hind femora d^ armed with a pair of long curved black 



spinous bristles, legs otherwise bristleless; halteres black; third vein 

 curving away from the fourth; pleurae shining; palpi and base of 



antennae yellow bispina, n. sp. 



Femora not so armed; species differing from preceding also in two or 

 more other characters 25. 



25. Third vein curving forward, widely diverging from the fourth; pleurae 



opaque pollinose except the center of the sternopleura; halteres and 



fringe of calypteres yellow diver gens Loew 



Third and fourth veins at least subparallel toward their tip; pleurae shining 

 excef)t rarely on the sutures 26. 



26. Legs without bristles, at most weak hairs on the base of the front femora 



beneath and near the apex of the hind ones; no dorsocentrals 27. 



Femora and tibiae with bristles; halteres yellow 31. 



27. Discal cell long, the ultimate section of the fifth vein much shorter than 



the preceding, posterior cross-vein opposite the end of the first vein, 

 the anterior cross- vein at or before the middle of the discal cell; 



mesonotum pubescent 28. 



Discal cell small, sections of the fifth vein nearly equal, the posterior 

 cross-vein before the end of the first vein, the anterior cross-vein 

 beyond the middle of the discal cell, the second section of the costa 

 shorter than the third 29. 



28. Hind tibiae ciliate along the outer edge; halteres black; veins dark, the 



second section of the costa equal to the third latipennis Melander 



Tibiae not ciliate; halteres yellow; veins brown, the second section of 

 the costa shorter than the third discalis, n. sp. 



