256 CALIFORNIA ACADEMY OF SCIENCES [Paoc. 4th See. 



Abdomen shining black with pollinose posterior borders, 

 complete on second, narrowly interrupted on first, third, 

 and following segments. Pile entirely whitish, longer and 

 tuft-like on the sides of the first three but more or less cov- 

 ering all the segments, including the genitalia. Legs entirely 

 black, including the ungues. Femora and basal two-thirds 

 of tibiae white pilose. First three joints of tarsi white pilose, 

 especially long and tuft-like on the middle pair. Most of 

 the bristles of the legs black but with a few white ones inter- 

 mixed. Wings hyaline, the veins black; anterior cross vein 

 a little before the middle of the discal cell. 



Female : Resembling the male in many respects. White 

 pile of face much thinner, the antennal arista a little longer 

 and more slender and pointed. Thorax more thickly pol- 

 linose and the markings more distinct, the two dorsal vittae 

 interrupted some distance from the scutellum by gray pollen; 

 pollen distinctly visible on the disk of the scutellum. Hal- 

 teres reddish yellow. Second, third and fourth segments of 

 abdomen with a complete pollinose band, the fifth inter- 

 rupted, the following entirely shining black. Segments fol- 

 lowing the third with very short, sparse white pile. 



Holotype, male, No. 836, and allotype, female, No. 837, 

 Mus. Calif. Acad. Sci. ; B. G. Thompson, collector, May 

 1919. These types are on the same pin and were taken in 

 coitu. 



Type locality, Burns, Oregon. 



The species is quite a distinct one and is in the group 

 which has the scutellum flattened and pollinose; it runs to 

 couplet 17 in Back's synoptic table but is quite different from 

 evidens. 



326. Cyrtopogon varipennis Coq. 



Parkdale, VI-8 (Cole). 1904, Proc. Ent. Soc. Wash. 

 VI, p. 184. 



327. Lasiopogon bivittatus Loew 

 Hood River, V-15 to VI-24 (Cole). 



