THE DIPTEROUS *GENUS DOLICHOPUS IN NORTH AMERICA. 277 

 No. 203, DOLICHOPUS SEXAKTICULATUS Loew. 



Bolichopus sexarticulatus Loew, Mod. N. Amer. Dipt., pt. 2, 1864, p. 62. — 

 Melander and Brues, Biol. Bull., vol. 1, 1900, p. 148. 



Male. — Length 5-6 mm.; of wing 4.5-5.5 mm. Face rather wide, 

 a little narrowed below; yellowish white, more yellow above. Front 

 green with bronze reflections, sometimes more blue-green, a little 

 dulled with yellowish pollen. Antennae yellow; third joint infus- 

 cated at tip, about as long as wide, pointed. Lateral and inferior 

 orbital cilia yellowish, about four of the upper cilia on each side black. 



Thorax green with bronze reflections and a median coppery vitta 

 on the dorsum, which is dulled with yellowish pollen, this pollen is 

 more gray along the front; pleurae dulled with white pollen. Ab- 

 domen green with coppery or bronze reflections; the white pollen on 

 its sides abundant and extending upon the dorsum. Hypopygium 

 with its basal portion metallic green, its apical half more yellow; 

 lamellae of moderate size, somewhat triangular, but rounded at 

 apex, whitish with a narrow black border which shades into the white ; 

 jagged and bristly at lower apical corner, otherwise fringed on apical 

 margin with little black hairs. 



Coxae yellow; middle and hind pairs with one large and one small 

 black spot on the outer surface; anterior surface of fore coxae with 

 white pollen and minute yellow hairs. Femora and tibiae yellow. 

 Middle and hind femora each with one preapical bristle, the latter 

 nearly bare on their lower half, which has only a few minute yellow 

 hairs. Middle tibiae with two large bristles on lower anterior edge, 

 their basitarsi with one rather small bristle near apical third of upper 

 edge. Posterior tibiae thickened, especially on basal half; the 

 usual glabrous stripe on upper surface broad but broken by the 

 irregular placing of the large bristles and a few hairs; inner surface 

 excavated on basal half, which is glabrous and covered with yellow 

 pollen. Fore tarsi (fig. 203a) twice as long as their tibiae, the first joint 

 being four-fifths as long as the tibia; first three joints rather slender, 

 yellow, second joint half as long as the first, third a little shorter 

 than the second; last two joints compressed; fourth nearly three- 

 fourths as long as third, about half as wide at apex as long, wholly 

 black, fringed above with little black hairs and with two long hairs 

 at upper apical corner; fifth joint formed of two parts, the basal 

 portion about as long as the fourth joint and a little wider, base deep 

 black, a Httle more than apical half white, claws placed near the 

 middle of this basal portion on its lower edge, attached to the upper 

 apical corner of basal part is the second part, an appendage which is 

 narrow at its base, widening apically, somewhat spatulate, deep black 

 for a httle more than half its length, with the apical part white; this 

 appendage has the appearance of a sixth joint, it is much smaller 

 than the basal portion, being little more than half as long and much 



