134 Proceedings of the Biological Society of Washington. 



considerable proximad of middle of frons; head higher than in male; para- 

 facial distinct but not as wide as the slender third antennal joint; palpi 

 broad. Otherwise as male. 



Length, 5-6 mm. Type, male, Plummer's Island, Md., August 28, 1912. 

 Allotype, Little Falls, D. C, August 22, 1915 (W. L. McAtee). This 

 species very closely resembles Hebecnema nigricolor Fallar, a European 

 species, which I supposed it to be until I obtained authentic European 

 specimens of that species. 



Hylemyia montana, sp. n. 



Male. — Black subopaque, densely brownish gray pruinescent. Head 

 yellowish testaceous, occiput fuscous, gray pruinescent; antennae black, 

 second joint brown; arista pale except at base; palpi fuscous. Thorax in- 

 distinctly trivittate. Abdomen with a poorly defined dorso central dark 

 vitta; hypopygial forceps yellowish, tips yellow. Coxae and all femora 

 largely fuscous, tarsi black. Wings yellowish, veins pale. Calyptra and 

 halteres yellow. Eyes separated by a little more than width of anterior 

 ocellus; arista with its longest hairs a little less than as long as width of 

 irregularly 2-rowed, sternopleurals 1:2. Abdomen slender, depressed; 

 fifth sternite with long narrow processes, each of which has some long bris- 

 tles along the middle directed slightly laterad and caudad, and 4 or 5 

 short equal sized closely placed setae at apex on inner margin directed 

 mesad and sometimes cruciate; inferior forceps long, thick at base, tapered 

 to a slender point, each with a few short hairs at tip on inner side. Fore 

 tibia usually with a median posterior bristle, the apex with a long curved 

 blunt black bristle on posterior side at apex ; fore tarsus compressed, about 

 as long as tibia; mid tibia with 3 or 4 very short setulae on posterior sur- 

 face ; mid tarsus very much shorter than its tibia ; hind femur with a com- 

 plete series of strong bristles on antero-ventral surface and a series of 

 closely placed short bristly hairs on postero-ventral ; hind tibia with 3 or 4 

 antero-ventral, 3 to 5 antero-dorsal, and 3 postero-dorsal bristles, the 

 posterior surface with a few setulose hairs on basal half; tarsus very little 

 and shorter than tibia. Costal thorn short; outer cross-vein nearly straight. 



Length, 5-6 mm. Type, Denver, Colo., June 15, 1916 (E. C. Jackson). 



Paratypes, Denver, Colo., July 19, 1914 (O. E. Jackson); Crow agency, 

 Montana, July 10, 1916 (R. Kellogg); Bozeman, Mont., July 3, 10, 15; 

 Florence, Mont., June 22, 1912; Armstead, Mont., July 3, 1913; Miles 

 City, Mont., July 15-16, 1915. 



Differs from coarctata Fallen in having the hind femora with postero- 

 ventral setulose hairs and the forceps differently shaped. 



