248 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



cally, yellowish, but black on upper edge and at apex; last three 

 joints black, third and fourth of nearly equal width, fifth about half 

 as long and wide as fourth, somewhat round in outline; second, third, 

 and fourth joints fringed above with black hairs. Hind tarsi black 

 from the tip of the first joint. Calypters and halteres yellow, the 

 former with black cilia, which often appear reddish in certain lights. 



Wings (fig. 181) tinged with brown on anterior half, more grayish 

 on posterior half; costa with an elongated enlargement at tip of first 

 vein, which is as long as the cross-vein; last section of fourth vein 

 bent near its middle; hind margin of wing a little indented at tip of 

 fifth vein; anal angle rounded. 



Female. — Face wide, of the usual length, silvery white; femora with 

 the same three bristle-like hairs before the preapical bristle as in the 

 male; middle tibiae with a bristle a little longer than the others near 

 its middle; their tarsi plain, slightly shorter than their tibiae, black 

 from the tip of first joint; still the second sometimes a little yellow- 

 ish; three middle joints slightly compressed; costa without an en- 

 largement at tip of first vein. 



Redescribed from specimens from Brookings, South Dakota; 

 August 12; Wisconsin, August; Moscow, Idaho (Aldrich), July 22; 

 Franconia, New Hampshire; Pullman, Washington (Melander), June 

 30; Lewiston, New York, August 11; Ithaca, New York, July 22; 

 Grange Island, New York, August 8; Yellowstone Lake, Montana 

 (Melander), August 9; Three Forks, Montana, August 1; Quebec, 

 Canada, August 10; Clayton, British Columbia, August 9; Ottawa,. 

 Canada, September 8; Ridgeway, Ontario, August 8, September 6. 



Type locality. — Red River of the North. Aldrich reports it from 

 South Dakota, Wyoming, Connecticut, and Wisconsin; Wheeler from 

 Wisconsin and Illinois; Melander and Brues from Massachusetts and 

 Pullman, Illinois. 



No. 182. DOLICHOPUS ALDRICHII Wheeler. 



Hygroceleuthus aldrichii Wheeler, Proc. Calif. Acad. Sci.. vol. 2, 1897, p. 3, 

 pi. 1, fig. 1-3.— Melander and Brues, Biol. Bull., vol. 1, 1900, p. 129, figs. 



Male. — Length 3.5-5 mm.; of wing 4-4.5 mm. Face rather nar- 

 row and long, not reaching the lower corner of the eye, yellowish 

 white, sometimes nearly pure white. Front shining green. Antennae 

 black with the first two joints yellow on the lower inner side; first 

 joint long and with long black hair; third joint oval, short, a little 

 pointed at tip, not much longer than wide; arista rather thick. Lat- 

 eral and inferior orbital cilia yellowish, about ten of the upper cilia 

 on each side black. 



Thorax green with bronze reflections and rather abundant gray 

 pollen on the dorsum. Abdomen green with coppery reflections on 



