THE DIPTEROUS GENUS DOLICHOPUS IX XOETH AMERICA. 211 



of the usual glabrous line on lower edge. Posterior tibiae sometimes 

 a little infuscated at tip, only a little thicker than the others, the two 

 rows of large bristles on upper surface are placed so close together 

 that the usual glabrous stripe between them can scarcely be traced. 

 Fore tarsi (fig. 151o) one and a third times as long as their tibiae; 

 second joint about three-fourths as long as first; first four joints 

 yellow, third scarcely one-third as long as second, fourth a little more 

 than half as long as third, scarcely as long as wide, a little com- 

 pressed; fifth black, much compressed, about as long as second, not 

 quite as wide near the tip as it is long, fringed above with little black 

 hairs. Middle tarsi a little longer than their tibiae, black from the 

 tip of the first joint, which has a large bristle above near apical 

 fourth. Hind tarsi wholly black, sometimes the first joint is more 

 dark reddish brown or even yellowish. Calypters and halteres 

 yellow, the former with black cilia. 



Wings (fig. 151) grayish, tinged with yellowish brown in front of 

 third vein and along the posterior veins; costa scarcely enlarged at 

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

 middle; hind margin of wing slightly indented at tip of fifth vein, 

 with a small sinus before and after the tip of sixth vein so as to leave 

 a slight lobe at tip of sixth vein and at the anal angle, which is 

 prominent; wing of somewhat equal width, still a little narrowed at 

 root. 



Perrtale. — ^Face wide, covered with gray pollen; fore tarsi plain, a 

 little longer than their tibiae, infuscated almost to their base, but 

 scarcely black even at tip, first joint scarcely longer than the two 

 following taken together, fifth a little longer and wider than fourth; 

 middle tibiae with four bristles below, one pair at apical third, one 

 bristle at basal third, and one halfway between these; wings more 

 evenly rounded than in the male, a little narrowed at root, anal angle 

 a little prominent. 



Described from 7 males and 4 females, taken by J. M. Aldrich, at 

 Mono Lake, CaUfornia, July 21-23. 



Type.—Msile, Cat. No. 23042. U.S.N.M. 



No. 152. DOLICHOPUS ^RATUS, new species. 



Male. — Length 5-6 mm.; of wing 4.75-5 mm. Face wide, a little 

 narrowed below, yellowish gray. Front mostly coppery with grayish 

 poUen. First antennal joint yeUow, sometimes with a blackish line 

 on upper edge; second and third joints black, third about as long as 

 wide, rounded at tip. Lateral and inferior orbital ciha yellowish, 

 about six of the upper cilia on each side black. 



Thorax bronze brown with a little green along the edges of the dor- 

 sum, which has coppery reflections and is covered with thick brown- 

 ish poUen; pleurae dulled with grayish white pollen. Abdomen 

 green with more or less coppery reflections; the white pollen on its 



