AMERICAN DIPTEKA. 267 



tarsi dark brown, front metatarsi of the male oblong, incrassate, not provided 

 with longer pile. Halteres black. Wings nearly hyaline, stigma dark brown. 

 3 mm. 



Pennsylvania (Osteu Sacken). 



Hilara basalis Loew. 

 Cent, ii, 45. 



Black, almost shining. Head black, occiput subcinerascent. Anteunte black. 

 Palpi yellowish. Proboscis shorter than the head. Dorsum of thorax subcinera- 

 scent, with very fine whitish pollen, clothed with black pile. Scutellem same 

 color as the thorax. The basal half of the abdomen testaceous or a little fuscous, 

 the apical half black, very faintly cinereous-poUinose. Legs yellowish, tarsi 

 except the base fuscous, the first joint of the fore tarsi of the male strongly 

 thickened ; the front tibife and the front metatarsi possess somewhat longer 

 blackish pile above. Halteres yellowish brown. Wings gray, stigma dark 

 brown. 3.3 mm. 



Illinois (Le Baron). 



Hilara uiaeroptera Loew. 

 Cent, iii, 32. 



Dark gray, opaque. Head concolorous, black-pilose. Antennae black, the first 

 two joints dark brown. Palpi piceous, provided with some longer black hairs. 

 Proboscis black, rather thick, shorter than the head. Dorsum of the thorax not 

 vittate, provided with rather long black pile. Ahdomen black, opaque, black- 

 pilose. Legs pale yellow, black-pilose, the outer half of the tibise and the whole 

 of the tarsi black ; the front metatarsi of the male moderately thickened, and 

 the front tibife bearing very long black hair above. Halteres yellowish. Wings 

 very large, distinctly grayish, subhyaline, pale yellowish at the base, veins sub- 

 fuscous, pale yellow at the base, stigma elongate, cinereous, very faint. 2.7 mm. 



District of Columbia (Osten Sachen). 



Hilara Intea Loew. 

 Cent, iii, 33. 



Yellow, opaque, clothed with short and sparse black hair. Head blackish 

 cinerascent, with whitish pollen. The basal joints of the antennae fuscous (the 

 third joint wanting). Palpi yellow; proboscis black, thick, shorter than the 

 head. Pleurse faintly marked with grayish spots. Abdomen marked with basal 

 blackish fascia on each segment. Legs paler than the rest of the body, the very 

 tip of the tarsi fuscous, and the fore metatarsi of the male incrassate. Halteres 

 pale yellow. Wings almost hyaline, pale grayish yellow, veins yellow, posterior 

 ones suhfuscous, second longitudinal recurved towards its apex, the front branch 

 of the third vein obliquely ascending, 2.5 mm. 



District of Columbia (Osten Sacken). 



Hilara tristis Loew. 

 Cent. V, 62. 



Wholly black, black-pilose, opaque, antennae, head, hypopygium, halteres and 

 legs concolorous, the pedicel of the halteres and the knees testaceous. Front 

 wholly velvety. Dorsum of the thorax sprinkled with very sparse, pale cinere- 



TRANS. AM. ENT. SOC, XXVIII. AUGUST, 1902. 



