122 PROCEEDINGS OF THE NATIONAL MUSEUM. vou. 62. 
lowish gray pollinose, with long black pile in the median portion; 
face gray pollinose, largely black pilose, the pile in the middle por- 
tion yellow. Palpi yellowish with yellow pile. Pile of the occiput 
and cheeks yellowish and not very dense. 
Thorax yellowish gray pollinose, with two faint vittae of paler 
color; pile of mesonotum yellowish white, with a few black hairs 
intermixed. Scutellum, pleura, and coxae thickly gray pollinose, the 
pile whitish. Halteres yellowish, base of knob brown. 
Abdomen black, with narrow yellow posterior margins to segments 
two, three, four and five; densely gray pollinose, with sparse, rather 
long erect yellow pile. Venter as above. Genitalia reddish yellow, 
with rather long yellow pile, a few black hairs above and on seventh 
segment. (Fig. 153 for structure.) Femora blackish, more or less 
yellowish toward apex, the pile largely vellowish white, some black at 
the apex; tibiae and tarsi yellowish, darkened apically. Wings yellow- 
ish and gray hyaline, the stigma pale brown, most of the veins yellow, 
but brown in certain sections, as the at tips of the veins, the fork of 
Rs and the cross veins; cell M-3 narrowly open. 
Female.—Length 9.5 mm. Resembles the male. Pile of face 
shorter and all yellowish, as on the cheeks and occiput; a few black 
hairs on the frons. The frons has two shining black hemispherical calli 
near the middle; pollen of frons and vertex golden yellow, that on 
the face and lower occiput white. 
Thorax with sparse erect black hairs and reclinate yellowish pile. 
Mesonotum largely pale brownish gray, the two vittae and lateral mar- 
gins paler brownish gray. Base of the scutellum broadly brownish. 
Abdomen black in ground color, posterior margins of the third to the 
last segment yellowish gray and yellow pollinose; posterior margin 
of the second segment whitish; the yellow color of the fifth broad, 
the segments beyond the fifth and the genitalia reddish yellow. Pile 
of the abdomen yellow, reclinate on the first two segments, erect on 
others; seventh segment and genitalia shining, with more or less black 
pile on the dorsum. Femora largely yellowish, darker above, the 
pile much shorter than in the male. Wings more brownish in color, 
the veins darker. 
Type localities.—Holotype, male, collected at Brigham, Utah, 
July 4, 1911 (J. M. Aldrich), and allotype, female, taken at Salt 
Lake City, Utah, July 18, 1917 (J. M. Aldrich), [U. S. National 
Museum]. 
Type.—Male, Cat. No. 25944, U.S.N.M. 
The holotype was taken on parsnip flowers, three male paratypes 
being taken at the same time. 
Paratypes.—The distribution according to five males and four 
females is: 
