224 A. L. MELANDER. 



those of scutellum longer than usual. A clear space present on pleurse in front 

 of the middle coxae. Abdomen of male cylindrical, a fringe on left side of hypo- 

 pygium consisting of white hairs. Legs including coxffi yellow; middle and 

 front femora subequal ; front tibife a little thickened ; spurs of middle trochan- 

 ters and of middle tibiffi black; tarsal joints sometimes faintly annulate; middle 

 femora with black setulse, and sparsely ciliate with yellow, middle tibise with 

 black setulse. Wings clear hyaline, veins pale yellow ; third and fourth veins 

 parallel, straight; second basal cell a little longer than first, its outer vein 

 oblique; anal cell nearly obsolete; anal angle rounded. 



One male and three females; Champaign Co., Illinois, and Brook- 

 ings, South Dakota. 



Platypalpus gilvipes Cuquillett. 

 Proc. Wash. Acad. Sci., 1900, p. 422. 



Black, first two joints of the antennae, palpi, halteres, legs and coxae yellow, 

 last joint of the tarsi brown ; third joint of the antennae about twice as long as 

 wide. Body polished, the front end of the pleurae to the posterior side of the 

 front coxae, also the lateral margins of the metanotum, encroaching slightly on 

 the pleurae, opaque gray pollinose. Wings hyaline, veins brown, the first and 

 second basals subequal. 2-3 mm. 



Popof Is., Alaska (Kincaid). 



TACHYDROMIA Meigen. 

 Rather small, slender flies, devoid of much pubescence, generally 

 black and with the wings more or less colored. Antennae short, 

 apparently two-jointed, the end joint with a long, outward-pointing 

 style. Proboscis at most as long as the head ; palpi with the bris- 

 tles on the underside sometimes as long as the proboscis. Eyes of 

 both sexes subcontiguous below the antennae. Abdomen length- 

 ened. Legs rather long, fore coxae more or less lengthened, fore 

 femora with small spines below. Wings as in Plaiypalpus, except 

 that the anal cell is completely wanting, or only the anal cross vein 

 in part present. 



Wings without cross-hands 2. 



Wings with two broad dark cross-bands 14. 



2. Thorax reddish Bacis Walker. 



Thorax black 3. 



3. Veins bordered with brownish 4. 



Veins not bordered 5. 



4. Cross-veins bordered ; third antennal joint dark inusta sp. nov. 



Antennae testaceous viltipeiinis Walker. 



5. Wings unicolorous •. 6. 



Outer part of wings more or less brown, clear at base 10. 



6. Femora and antennae wholly black 7. 



Part of the femora more or less yellow 8. 



