THE DIPTEEOUS GENUS DOLICHOPUS IN NORTH AMERICA. 249 



the hind margins of the segments; the white pollen on its sides 

 conspicuous. Hypopygium black; ^^ ^^^^^ ^ ".^^ ; ^^.^ 

 what triangular, yellowish with a brown border, which is more 

 rotpicuol'whe;!^ from below, scarcely at all jagged, frmged 



with httle yellowish hairs. 



Fore coiae vellow with a green stripe on outer posterior edge, 

 .interior surface with silvery pollen and minute delicate white hairs 

 Middle and hind coxae black with yellow tips. Femora and tibae 

 yellow. Middle and hind femora each with one preapical tnstle the 

 latter without ciUa below. Posterior tibiae a little thickened, blacteh 

 at tip, but the black not well defined, with a row of five large bristles 

 on h lower outer edge, their inner surface with a glabrous stripy 

 which is widest at their base. Fore tarsi plain, no* as l°ng as tto 



tibiae, stout, black from the tip of '^e A-' '»'"'• ,";t"!/Z fet 

 182a) about as long as their tibiae, black from the tip of *e f^rst 

 joint, which is mostly whitish, without a bristle ^>ove; -^°f ' ^'^f 

 ind fourth joints a httle compressed, but rather thick, fringed on both 

 Xs with black hairs. Hind tarsi black with the base of the first 

 Joint a little yellowish; calypters and halteres yellow, the former with 



lonsr black cilia. , . , ■,...] 



Winc^ (fi- 1S21 grayish, darker in front of third vein; costa a httle 

 thickened Tt tip of first vein, but this thickening is cylmdrical and 

 more readily seen from the front of the wing; last sedition of ourth 

 vein considerably bent near its middle; third vein hent backwaro 

 at tip; hind margin of wing a little indented at tip o fifth, bilobed 

 at the anal angle, which is cut off very straight at the base ot the 

 wine, not rounded as usual. 



FmaZe.-Face wide but rather long, yellowish white; antennae 

 and fore and hind tarsi about as in the male; fore coxae covered with 

 black hairs on the anterior surface; middle tarsi slightly compressed, 

 colored about as in the male; wings with the hmd margin evenly 

 rounded; costa without an enlargment. 



Redescribed from 8 males and 4 females from Colorado and Moscow, 

 Idaho (Aldrich); one of the latter was taken Aug. 23; 1 ^^^^ ^^^^ 

 Pulhnan, Washington, July 12; and 1 female taken at Umta National 

 Forest, Utah, Aug. 29, on Currant Creek, at 8,000 feet elevation. 



Tiive localities.-Uoscow, Idaho, Wyoming; Melander and Biues 

 report it from Idaho, Wyoming, and Colorado. 



Type.-^ln American Museum of Natural History, New 1 ork City. 



No. 183. DOLICHOPUS BOLSTERI, new species. 



Fig. 1, page 3. 

 il/aZ6.-Length, 5 mm.; of wings, 5.5 mm. Face wide scarcely 

 narrowed below, silvery gray. Front shining green Antennae 

 wholly black; third joint about as long as wide, somewhat triangulai, 



