THE DIPT^EROUS GENUS DOLICHOPUS IN NOETH AMERICA. 181 



size, somewhat triangular in outline, with the outer part rounded, 

 whitish with a narrow black border on apical margin, jagged and 

 bristly on the lower half of the rounded apical margin, upper half 

 with delicate brown hairs, fringed on the lower edge, which is nearly- 

 straight, with a few delicate little pale hairs. 



Fore coxae yellow, with little black hairs on inner half of anterior 

 surface; these hairs sometimes cover the whole of the apical half and 

 do not always reach the base of the coxae; middle coxae blackish 

 on outer surface except at tip; hind coxae usually wholly yellow, 

 sometimes a little blackened on outer surface. Femora and tibiae 

 yellow. Middle and hind femora each with one preapical bristle, 

 the latter nearly glabrous below, except for a row of minute yellow 

 hairs -on lower inner edge. Posterior tibiae slightly thickened, 

 blackened a little at tip, but sometimes only slightly so. Fore tarsi 

 (fig. 126a) one and a fourth times as long as their tibiae, J[irst three 

 joints dark yellow, fourth and fifth black, a little compressed, upper 

 edge of fifth fringed with stiff black hairs, fourth nearly as wide at 

 tip as long, about half as long as fifth; first joint about as long as the 

 three following taken together. Middle tarsi about one and a third 

 times as long as their tibiae, black from the tip of the first joint, 

 still the base of the second joint often yellowish, their basitarsi with 

 a bristle above; middle tibiae with three bristles below, one pair at 

 apical tliird and one bristle at basal third. Hind tarsi wholly black, 

 one and a third times as long as their tibiae. Calypters and halteres 

 yellow, the former with black cilia. 



Wings (fig. 126) grayish, usually slightly brownish along the veins 

 and sometimes in front; costa not thickened at tjp of fu'st vein; 

 last section of fourth vein bent at right angles before its middle and 

 with a stump of a vein; frequently the upper bend is also a right angle 

 and may even have a stump ; hind margin of wing a little indented 

 at tip of fifth vein; anal angle prominent. 



Female.- — Face a little wider than in the male, antennae nearly 

 wholly yellow ; fore tarsi colored about as in the male, but the fourth 

 and fifth joints are not compressed; otherwise about as in the male. 



Redescribed from numerous males and females from the followins: 

 locations: Custer, South Dakota; Brookings, South Dakota, June 12 

 (Aldrich) ; Lawrence and Baldwin, Kansas ; Riley County, Kansas, 

 Sept.; Lafayette, Indiana, June 6-Oct. 13; Fargo, North Dakota; 

 Ohio; Woods Hole, Massachusetts; Hanover, New Hampshire; 

 Ames, Iowa; western New York, June 13-Oct. 6; Cliicago, Illinois; 

 Fort Erie, Ridgeway, Toronto, Kearney, and Sudbury, Ontario, 

 June 22-Aug. 8; Montreal, Quebec, June 15. 



Type localities. — Chicago, Illinois, and Nebraska. Aldrich (in 

 Biologia Cent. Amer.) reports it from Cuernavaca, Mexico, much 

 farther south than any other true Doll cho pus has been found; John- 



