THE DIPTEROUS GEXUS DOLICHOPUS IjST NORTH AMERICA. 203 



Lateral and inferior orbital cilia white, about six of the upper cilia 

 on each side black. 



Thorax green with bronze reflections, which sometimes form a 

 median vitta on the dorsum; dorsum dulled with a little grayish 

 poUen; pleurae dulled with white pollen. Abdomen green with coj)- 

 pery reflections and black incisures; the white poUen on the sides 

 extends over the dorsum. Hypopygium black; its lamellae of mod- 

 erate size, somewhat oval, whitish with narrow black border on apical 

 and upper margins, jagged and bristly at apex, fringed above with 

 black, below with a few pale hairs. 



Fore coxae yellow, their anterior surface covered with silvery pol- 

 len and minute white hairs. Middle and hind coxae black with yellow 

 tips. Femora and tibiae yellow. Middle and hind femora each with 

 one preapical bristle, the latter without cilia, but with minute yellow 

 hairs below. Posterior tibiae a little infuscated at tip, especially on 

 inner side, scarcely thickened, the usual glabrous stripe on upper 

 surface distinct, but a little broken by a few little hairs; there is also 

 a glabrous line just inside of the inner row of large bristles; middle 

 and hind tibiae each with one bristle below. Fore tarsi (fig. 144a) 

 nearly twice as long as their tibiae, slender, first four joints yellow, 

 each more slender than the preceding one; first nearly three-fourths 

 as long as the tibiae, third and foiu'th of nearly equal length, each 

 a little shorter than the second; fifth joint compressed, black with 

 the extreme base white, nearly half as long as the fourth, oval, a little 

 longer than wide. Middle tarsi one and a fourth times as long as 

 their tibiae, infuscated from the tip of the first joint; first joint with- 

 out a bristle above. Hind tarsi wholly black, or sometimes the first 

 joint a little reddish at base. Calypters and halteres yellow, the 

 former with black cilia. 



Wings (fig. 144) grayish, sometimes with a slight yellowish brown 

 tinge in front of the third vein; costa slightly enlarged at tip of 

 first vein and tapering to its tip; last section of fourth vein a little 

 bent near its basal third; third and fourth veins distinctly approach- 

 ing each other toward their tips; hind margin of wing a little indented 

 at tip of fifth vein, and with a slight sinus near sixth vein; wing 

 slightly narrowed toward the base, still the anal angle rather prom- 

 inent, forming on account of the sinus a small lobe-like projection. 



Female. — E'ace wide, grayish white; third antennal joint only a 

 little longer than wide, pointed at tip; fore coxae with a few minute 

 black hairs along the inner edge; fore tarsi plain, a little longer than 

 their tibiae, first four joints dark yellow, fifth joint black, all the 

 joints of decreasing length; middle tarsi only a little longer than their 

 tibiae; hind margin of wing more evenly rounded than in the male, 

 the anal angle rounded; wing not narrowed toward the base. Other- 

 wise about as in the male. 



