172 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



Calypters and halteres yellow, the former with black cilia, still they 

 appear yellowish in certain lights. 



Wings grayish; costa without an enlargement at tip of first vein; 

 last section of fourth vein bent at its middle; third vein very nearly 

 parallel with fourth beyond the bond in fourth and widely separated 

 from it; hind margin of wing not indented at tip of fifth vein, evenly 

 rounded, the anal angle not at all prominent. 



Female. — Wings, coxae, and -bristles of middle tibiae and basi- 

 tarsi as in the male. Face wide, white; third antennal joint smaller; 

 fore tarsi plain, a little longer than their tibiae, brownish from the 

 base, but only the fifth joint black, second joint a little more than 

 half as long as first, third a little shorter than second, fourth and fifth 

 together as long as second, fourth a little longer than fifth; middle 

 tarsi as long as their tibiae; hind femora without cilia below; pos- 

 teria tibiae only a little thickened and a little blackened at tip, but 

 they could not be said to be black at tip; calyp teres with black cilia. 



Redescribed from 1 male taken at Kukak Bay, Alaska, July 4, and 

 1 female from Europe. 



Type. — In the University of Lund, Sweden. 



No. 120. DOLICHOPUS POLLEX Osten Sacken. 



Dolichopus pollex Osten Sacken, Western Diptera, 1877, p. 314. 



Male. — ^Length 4.7-6 mm.; of wing 4.2 mm. Face wide, a little 

 narrowed below, silvery gray, tinged with yellow. Front reddish 

 copper}', sometimes edged with green. Antennae wholly black, 

 third joint but little longer than wide, obtusely pointed at tip. 

 Lateral and inferior orbital cilia yellowish, about eight of the upper 

 cilia on each side black. 



Thorax green with reddish coppery reflections on the dorsum, 

 sometimes mostly coppery, at others with three narrow coppery 

 vittae; not very shining; pleurae dulled with white pollen. Abdomen 

 green with coppery reflections, which are most conspicuous on th(» 

 apical segments, somewhat dulled with white pollen. Ilypopygium 

 black; its lamellae rather large, nearly one and a half times as long as 

 wide, oval, whitish, sometimes tinged witli brownish yellow, with a 

 black border on upper and apical margins, a little jagged r.nd bristly 

 on apical margin, especially at lower corner, fiinged above with 

 black hairs. 



^Vll coxae black; fore and middle paiis with yellow tips, their 

 anterior surface covered with little black hairs. Femora and tibiae 

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

 latter ciliated on lower inner edge with black hau"s, the longest of 

 which are neaily as long as the width of the femora. Posterior tibiae 

 blackened at tip for more than one-fourth their length, a little thick- 

 ened, their bristles large with about eight in a row; the glabrous stripe 



