AMERICAN DIPTERA. 265 



men concolorous with the scutellum, black-pilose. Legs wholly black, with 

 short black pile ; the anterior metatarsi of the male oblong, incrassate. Wings 

 blackish gray, the stigma dark fuscous. 



District of Columbia (Osten Sacken). 



Hilara uiiicolor Loew. 

 Cent, ii, 37. 



Head black, with black pile, the occiput cinereous-black, antennae and palpi 

 black, the proboscis very short. Thorax cinereous-black, opaque, covered with 

 rather close black pile. Scutellum concolorous with the thorax. Abdomen 

 black -cinereous, opaque, with black pile. Legs wholly black, with short black 

 pile, the hind tibise covered with somewhat longer black pile ; the front meta- 

 tarsi (male) thickened. Halteres black. Wings pale cinerascent, stigma black. 

 3 ujm. 



Maryland (Osten Sacken), Massachusetts (G. deN. Hough). 



Hilara nigriveutris Loew. 

 Cent, ii, 38. 



Head black, with black pile, antennse concolorous, occiput cinereous. Palpi 

 yellowish, fuscous at base. Proboscis almost equal to the head. Thorax black- 

 cinereous, closely black-pilose. Scutellum concolorous with the thorax. Abdo- 

 men black, shining, with black pile. Anterior coxte yellowish, fuscous at base, 

 posterior coxse generally wholly black, often testaceous at the tip. Legs black, 

 with short black pile, the base and the very tips of the front femora always yel- 

 lowish, the base of the middle femora less often testaceous ; front metataisi of 

 the male oblong, incrassate. Wings very pale cinerascent, stigma black. 2.6 mm. 



Pennsylvania (Osten Sacken). 



Hilara triTittata Loew. 

 Cent, ii, 39. 



Subopaque, black -cinereous. Head black, the frontal triangle larger than in 

 the other species, it and the face cinerascent. Antennae black. Palpi black, sub- 

 cinerascent. Proboscis a little shorter than the head. Thoracic dorsum opaque, 

 with fusco-cinereous pollen, three almost complete fuscous vittse present, the 

 black pile very short. Scutellum and pleurte coiicolorous. Abdomen subopaque, 

 with fusco-cinereous pollen, clothed with very pale subfuscous pile. Legs black, 

 the pile very short. Wings cinereo-hyaline, stigma dark fuscous. 4.3 mm. 



Illinois (Le Baron). 



This species is very common in central Texas during the very 

 early part of spring. For an account of its habits see antea, p 200. 



Hilara mutabilis Loew. 

 Cent, ii, 40. 



Black. Head black, antennae and palpi black, proboscis a little shorter than 

 the head. Thoracic dorsum clothed with rather long black pile, and covered 

 with cinereous pollen, so that seen from the side it is wholly cinereous, viewed 

 from above it seems marked with three black vittte, the middle one complete the 

 side ones much shortened. Scutellum concolorous with the thorax. Abdomen 



TRANS. AM. ENT. SOC, XXVIII. (34) AUGUST, 1902. 



