8 PROCEEDINGS OF THE, NATIONAL MUSEUM. vol.63, 



hind ones with one veiy small preapical bristle, their hair short, 

 except a few longer hairs at base above. Fore and middle tibiae 

 brown at base, apical half yellow, their bristles long, middle ones 

 with a row of four bristles on lower anterior edge. Hind tibiae 

 black at base and tip, still mostly yellowish, sometimes only the 

 extreme base infuscated, their bristles rather strong. Fore tarsi a 

 little longer than their tibiae; first joint a little enlarged at tip and 

 extending beyond the base of second joint, which is slightly com- 

 pressed, except at tip, of about equal width, three-fourths as long as 

 lirst; fourth and fifth of about equal length and taken together 

 about as long as third. Middle tarsi black from the tip of the first 

 joint, still sometimes the second is yellowish at base. Hind tarsi 

 wholly black, with the first and second joints of about equal length. 

 Calypters, their cilia, and the halteres pale yellow. 



Wings grayish, veins brown or yellowish; third vein bent back- 

 ward, at tip it is a little recurved forward; last section of fourth 

 vein bent beyond its middle, nearly parallel with third toward its 

 tip, ending in the apex of the wing ; last section of fifth vein nearly 

 one and one-third times as long as the cross-vein. 



Female. — Face broad, its pollen coarse and yellowish ; suture near 

 the center of its length, lower portion with oral edge rounded, and 

 with the metallic green groimd color sliowing through the pollen. 

 Antennate small, third joint not longer than wide. Beard white, 

 rather abundant on the sides. Thorax with the posterior part of the 

 dorsum more or less coppery red. Hairs on the dorsum of the ab- 

 domen mostly whitish, those on the sides of first and second seg- 

 ments moderately long, white. Fore coxae with white hairs. Fore 

 femora black or green with their tips broadly yellow, and sometimes 

 yellow below, their posterior surface with rather long white hair and 

 several small black bristles near the tip. Middle and hind femora 

 yellow, the latter more or less blackened at tip, at least above, and 

 with one small preapical bristle; middle ones with two or three pre- 

 apical bristles on each side. All tibiae yellow ; posterior ones black- 

 ened a little at base and tip ; middle ones with two bristles on anterior 

 surface. Fore tarsi as long as their tibiae, darkened toward their 

 tip, last joint black, second joint a little more than half as long as 

 first, last three joints of about equal length, still the fourth a little 

 the shortest. Middle tarsi blackened from the tip of the first joint, 

 which is as long as the three following taken together ; fourth shorter 

 than fifth. Hind tarsi wholly black, first and second joints of equal 

 length. 



Described from seven males and seven females. Five males were 

 taken at Fairbanks, July 1-4; one at Nenana, June 28, and one at 

 Anchorage, June 15; five females were taken at Anchorage, June 

 13-28; one at Skagway, June 4, and one at Nenana, June 28. 



r2//)e.— Male, Cat. No. 25959, U.S.N.M. 



Type and allotype were taken at Nenana, Alaska, June 28. 1921. 



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