THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 255 

 No. 187. DOLICHOPUS DAKOTENSIS Aldrich. 



Dolichopus ddkotensis Aldrich, Kansas University Quarterly, vol. 2, 1893, p. 11, 

 pi. 1, fig. 1. 



Male. — Length 6 mm.; of wing the same. Face narrow, golden 

 yellow, a little more whitish below. Front shining green. Antennae 

 wholly black or nearly so; third joint scarcely longer than wide, 

 somewhat conical in outline, obtusely pointed at tip. Lateral and 

 inferior orbital cilia yellow, four or five of the upper cilia on each 

 side black. 



Thorax green, with considerable white pollen on the front of the 

 dorsum, the pollen on the center of the dorsum is more brownish and 

 leaves a rather broad median vitta which is more shining and some- 

 times coppery; pleurae dulled with white pollen. Abdomen green, 

 with black incisures and coppery reflections; the white pollen on its 

 sides abundant and extending upon the dorsum. Hypopygium 

 black; its lamellae (fig. 187a) large, somewhat elliptical, twice as long 

 as wide, whitish with rather \vide black apical border, jagged and 

 bristly at lower corner, otherwise fringed with yellowish hairs. 



Fore coxae yellow, anterior surface with minute yellow hairs. 

 jVIiddle and hind coxae black vnih. yellow tips. Femora and tibiae 

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

 latter ciliated with rather scattering whitish hairs for nearly their 

 entire length, the longest of which are scarcely as long as the width 

 of the femora. Posterior tibiae thickened, inner surface with a broad 

 glabrous space, extending from the base nearly to the tip. Fore 

 tarsi (fig. 187&) twice, or sometimes more than twice, the length of 

 their tibiae; second joint scarcely two-thirds as long as first, third 

 and fourth of nearly equal length, each about two-thirds as long as 

 second, and three-fourths as long as fifth; first and second, slender, 

 yellow; third and fourth compressed, silvery white, widening from 

 the base of third to tip of fourth; fifth much compressed, black, 

 two-thirds as wide as long. Middle tarsi longer than their tibiae, 

 infuscated from the tip of the first joint, still with the bases of the 

 second and third ones paler, only their tips black. Hind tarsi black 

 from the tip of the first joint, but sometimes colored like the middle 

 ones. Calypters, their cilia, and the halteres yellow. 



Wings (fig. 187) grayish; costa distinctly enlarged at tip of first 

 vein, this enlargement tapering into the costa, but not reaching half 

 the distance to the tip of second vein; last section of fourth vein a 

 little bent near its basal third; hind margin of wing scarcely indented 

 at tip of fifth vein, a little fiattened from the apex of the wing to the 

 tip of the fifth vein, expanding basally from fifth vein, then narrowing 

 to tip of the sixth vein; anal angle prominent. 



Female. — Face mde, white; fore tarsi plain, last two or three joints 

 black, fifth joint longer than fourth, nearly as long as third; hind 



