THE DIPTEROUS GENUS DOLTCHOPUS IN NORTH AMERICA. 247 



also in having the cilia on the hind femora longer and mo^'e delicate. 

 The Loew specimen differs from the others in having the front 

 violet and the face white; the bend in the fourth vein is greater, 

 almost broken. I do not think there is any doubt of its being the 

 same species. 



No. 181. DOLICHOPUS LATIPES Loew. 



Hygroceleufhus latipes Loew, Neue Beitr., vol. 8, 1861, p. 5; Mon. N. Amer. 

 Dipt., pt. 2, 1864, p. 17.— Aldrich, Kansas Univ. Quart., vol. 2, 1893, pp. 

 24 and 155-, pi. 1, fig. 26.— Wheeler, Proc. Calif. Acad. Sci., vol. 2, 1897, p. 

 2.— Melander and Brues, Biol. Bull., vol. 1, 19G0, p. 128, fig. 



Male.— Ijength 5.5-6 mm.; of wing 5 mm. Face moderately 

 narrow, long, reaching the lower corner of the eye, of nearly equal 

 width, silvery white, slightly tinged with yellow just below^ the 

 antennae. Front dark shining green. Antennae yellow; first joint 

 long; third with the apical half blackened, oval, scarcely pointed at 

 tip, about one and a half times as long as wide. Lateral and inferior 

 orbital cilia yellowish white, four or five of the upper cilia on each 

 side black. 



Thorax dark shining green with a little gray pollen on the anterior 

 part of the dorsum; pleurae dulled with white pollen. Abdomen dark 

 shining green, sometimes with bronze reflections; the white pollen 

 on its sides moderately abundant. Hypopygium black with green 

 reflections; its lamellae rather small, somewhat quadrilateral but 

 with the apical margin broadly rounded, whitish with a black border 

 on the apical margin, which is jagged and bristly. 



Fore coxae yellow with a few minute yellow hairs on their anterior 

 surface and usually with a few black ones on inner edge near the base; 

 middle and hind coxae black with yellow tips, sometimes the latter 

 mostly yellow, blackened only on the basal half of outer side; femora 

 and tibiae yellow; middle and hind femora each with one preapical 

 bristle, the latter without cilia below, but they have three bristle- 

 like hairs on upper outer edge; these are scarcely in a row with the 

 preapical bristle, and increase in length apically; middle tibiae with a 

 bristle on upper side near the middle which is nearly twice as long as 

 the other bristles on these tibiae, and with two large bristles below, 

 one near basal and one near apical third. Posterior tibiae but little 

 thickened, their bristles longer than usual; on their inner surface 

 there is a glabrous stripe just inside of the inner row of large bristles, 

 which is often of a darker color. Fore tarsi a little longer than their 

 tibiae, black from the tip of the first joint, which is nearly as long as 

 the remaining four taken together; fifth joint a little longer than the 

 fourth; middle tarsi (fig. 181a) scarcely longer than their tibiae; 

 first joint normal, about as long as the three following joints taken 

 together, without a bristle above, yellow or whitish with extreme 

 tip black; last four joints compressed; second joint widening api- 



