THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 85 



Female. — Like the male, except that the face is a little wider and 

 more white than silvery; the hind femora are without cilia, and the 

 costa is not enlarged at tip of first vein. 



Redescribed from 4 males and 3 females in the collection of J. M. 

 Aldrich, 4 of these are from Colorado and were taken by C. F. Baker, 

 and 3 from Mount Washington, New Hampshire, taken by Mrs. 

 Slosson. 



Type locality. — Sitka, Alaska. Coquillett reports it from several 

 places in Alaska. 



No. 45. DOLICHOPUS ALBICILIATUS Loew. 



Dolichopus albicilmtus Loew, Cent., vol. 2, 1862, No. 59; Mon. N. Am. Diptera, 

 pt. 2, 1864, p. 31.— Wheeler, Psyche, vol. 5, 1890, p. 338.— Aldrich, Kan- 

 sas Univ. Quart., vol. 2, 1893, p. 9; Cat. N. Amer. Diptera, 1905, p. 299.— 

 Melander and Beues, Biological Bulletin, vol. 1, 1900, p. 148. 



Male. — Length 4.5-5 mm.; of wing 4-4.5 mm. Face narrow, sil- 

 very white, a little yellowish just below the antennae. Front blue 

 green. Antennae wholly black; third joint scarcely longer than wide, 

 somewhat conical in outline, a little pointed at tip. Lateral and in- 

 ferior orbital cilia white, a few nearest the black cilia yellowish ; the 

 black cilia descend nearly to the middle of the eye height. 



Thorax shining blue green; pleurae dulled with gray pollen. Ab- 

 domen green with black incisures and sometimes with distinct cop- 

 pery reflections; the white pollen on its sides is not very abundant. 

 Hypopygium black; its lamellae (fig. 45a) rather large, nearly or- 

 bicular in outline but narrowed into the stem, whitish with broad 

 black border on apical portion, which shades into the white, a little 

 jagged on apical margin with one or two branched bristles at lower 

 corner, otherwise fringed on apical edge with long, bent black hairs 

 and on lower edge with short delicate brown hairs. 



Coxae and femora black with yellow tips. Fore coxae with white 

 pollen and little black hairs on the anterior surface. Middle and 

 hind femora each with one preapical bristle, the former with short 

 delicate hairs below and the latter ciliate with long black hairs on, 

 their lower surface, the longest of these hairs longer than the width 

 of the femora. Tibiae yellow; posterior pair a little thickened, black 

 on inner side and at tip on outer side for one-fourth their length. 

 Fore tarsi a little longer than their tibiae; black from tip of first 

 joint; first joint as long as the remaining four taken together. Mid- 

 dle tarsi longer than their tibiae, black from the tip of the first joint. 

 Hind tarsi wholly black. Calypters and halteres yellow, the former 

 with black cilia. 



Wings (fig. 45) grayish; costa with a small knotlike enlargement 

 at tip of first vein; last section of fourth vein a little bent at its 



