OSTEN SACKEN ON WESTERN DIPTERA. 247 



Male. — Frontal triangle black, with short, erect, black pile ; face with 

 a dense covering of short snow-white pile ; antennae black ; occiput 

 black, with appressed white hairs along the orbits 5 thorax grayish - 

 black, with a dense covering of delicate, downy, whitish-gray pile, which 

 in an oblique light looks altogether white ; the few bristles on the ante- 

 scutellar callosities and on the scutellum are whitish, almost colorless; 

 abdomen black, with the same covering of grayish-white pile, which is 

 longer here on the sides. Halteres whitish ; knob brownish. Legs black, 

 densely clothed with white scales ; spines on femora and tibiae whitish- 

 yellow. Wings, including the costal cell, of a pure hyaline ; veins, ex- 

 cept at the root, black ; costal and first longitudinal brown. 



Female. — Like the male, but the front is slightly brownish pruinose, 

 and has, besides the erect, black pile, some short, recumbent, yellowish 

 hairs. The hind margins of the abdominal segments are beset with 

 some short, appressed, whitish hairs, forming cross-bands. 



Hal). — I have a single male, which I took near the Salt Lake, Utah, 

 August 1. One of the females is from Sonoma County, California, July 

 6; the other from the Shasta district (H. Edwards, July, 1875). 



Oncodocera. 



Oncodocera leucoprocta Wiedemann, i, 330 {Mulio)) male (syn. 

 Oncodocera dimidiata Macq., D. E., ii, 1, 84, female). — Middle and 

 Southern States ; Illinois ; Wisconsin. 



Leptochilus modestus Loew, Centur., x, 40. — Texas. ^ I do not know 

 Aphcebantus cervinus Loew, Centur., x, 39. — Texas, j these species 



BcmBYLius. 



The species from the Atlantic States may be grouped as follows : — 



1. Anterior half of the wings brown, with a well-defined, sinuous, pos- 



terior limit of that color : 

 fratellus Wied., i, 583. 



Syn. — vicinus Macq., ii, 1, 98. 



albipectus Macq., 5e suppl., 82. 



cequalis Harris {nee Fabr.), 3d edit., 604. 



major Kirby, Fauna Bor.-Am., 312. 



2. Wings brown at base, and with brown spots on the posterior half : 



pulcliellus Loew, Centur., iv, 47. 

 pygmcew Fab., Wied., i, 351. 



3. The brown of the basal half of the wings is gradually evanescent 



posteriorly : 

 atriceps Loew, Centur., iv, 49. 

 mexicanus Wied., i, 338. 



SYX.—fulvilasis Macq., 5e suppl. ) Synonymy on the authority of Mr. 



philadelphicus Macq., ii, 1, 99. $ Loew, in litt. 



variiis Fab., Wied., i, 335. 

 validus Loew, Centur., iv, 48. 



