174 ERNEST A. BACK. 



of the occiput of the same color. Antennae yellow; style black. 

 Thorax reddish-brown, light grayish pruinose except a wide median 

 and two lateral stripes which are polished and range from deep testa- 

 ceous to black. Abdomen black, brownish pruinose; the first seg- 

 ment and both ends of the following segments grayish pruinose. Legs 

 ranging from pale yellow to deep testaceous, front and middle pairs 

 with a dark line along the anterior side of the femora and tibiae. Hind 

 femora somewhat incrassate, a broad band before the apex and the 

 apical half of the hind tibise brown; apices of all the tarsal segments 

 yellowish-brown; empodia about half as long as the claws. Wings 

 hyaline, at apex narrowly gray; fourth posterior cell with a long 

 peduncle. 



Type. — U. S. N. M., Cat. No. 7,945. Type series consists 

 of three female specimens. 



Habitat. — Delaware Co., Pa. (C. W. Johnson); D. C. (June 

 22) ; Carolina (Macquart) ; Tex. (Belfrage). The type material 

 is from Washington, D. C, and Texas. 



Prof. C. W. Johnson has in his collection two females and 

 a male and female in coitu — all from Delaware Co., Pa. — and 

 there is one female without label in the collection of the Am. 

 Ent. Soc. of Phila. They show a variation from a nearly 

 testaceus mesonotum to one with a single large black vitta, 

 up to those with three stripes on the mesonotum; the stripes 

 ranging from deep testaceous to black. 



DASYPOGONIN^. 



TOAVNSENDIA. 



Townsendia Williston, Kans. Univ. Quart., iv, 107, 1895. 

 Townsendia Williston, Biologia, Dipt., i, 307, 1901. 



" Very small species. Head broad, much broader than high. 

 Front very broad above, about three-fourths the width of 

 the head; narrow below, the sides gently convex, only mod- 

 erately excavated, nearly bare, with some bristles at the 

 vertex and on the ocellar tubercle. Faces narrow, with par- 

 allel sides, flat, much receding, not at all visible in profile; 

 with a thin row of bristles on the oral margin, otherwise wholly 

 bare. Antennae not as long as the head, situated near middle 

 of head in profile; segment 1 shorter than segment 2, the 

 latter about as broad as long, segment 3 longer than the first 

 two taken together, gently tapering from near its base; style 



