302 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



pile beiug only perceptible. The thorax is more densely pollinose than 

 in the male ; a grayish pollen forms a Y-shaped figure posteriorly, the 

 apex of which rests on the scutellum, the ends branch off on each side 

 along the thoracic suture; the geminate grayish stripe is longitudinally 

 divided by a more yellowish line ; the usual brownish shadows in the 

 humeral region. Length 9-10 mm . 



Hal). — Webber Lake, Sierra Nevada, California, July 22. A male and 

 female ; in excellent preservation. It will not be difficult to recognize 

 this remarkable species. 



7. Cyrtopogon princeps n. sp., $ . — Front tarsi remarkably long, once 

 and three-quarters the length of the tibia; their whole upper side beset 

 with a dense fringe of silvery pile ; hind femora, tibiae, and tarsi on the 

 upper side with a similar, but broader, covering of silvery pile. Face 

 and front with a brownish-yellow pollen; mystax pale yellow, black 

 only above the mouth and on the lower part of the face; lower part of 

 the occiput with white, upper part and vertex with black pile ; third an- 

 tenna! joint red, rather long and slender, the style black. Thorax 

 black, somewhat shining posteriorly, and somewhat brownish-pollinose? 

 especially about the humeri ; scutellum black ; thoracic pile black. Ab- 

 domen black, shining, with black pile ; segments 2-6 with yellowish- 

 gray pollen on the hind margins ; on the second segment, this pollen is 

 visible on the sides only ; on the third and fourth, it forms an interrupted 

 cross-band; on the two following segments, this cross-band is broader and 

 only subinterrupted by a deep emargination ; the sixth segment is entirely 

 covered with the gray pollen, except a small black triangle in front ; hy- 

 popygium black, with, black pile, and only a small fringe of minute yel- 

 lowish hairs at the extreme end. Legs black, ornamented as described 

 above ; ungues whitish, with black tips. Wings uniformly blackish • 

 veins normal ; fourth posterior cell hardly coarctate at all. Length 

 10.5 mm . 



Hal). — Webber Lake, Sierra Nevada, California. A single male. A 

 very remarkable species, easily recognizable by the blackish tinge of the 

 wings and the ornamentation of the front and hind legs. 



8. Cyrtopogon cretaoeus n. sp., 9 . — Thoracic dorsum rather evenly 

 clothed with a grayish- white pollen, completely concealing the ground . 

 color; the coloring of this pollen is rather uniform, a geminate median 

 stripe is hardly perceptible; ante-scutellar callosities black, shining; scu- 

 tellum black, brownish-pollinose at the base; pleurae with dense yellowish- 

 gray pollen. Abdomen shining black ; segments 2-5 each with a moder- 

 ately broad cross-band of yellowish- white pollen on the hind margins. Face 

 and front densely covered with yellowish-gray pollen ; mystax white above, 

 black below above the mouth ; vertex and upper part of the occiput with 

 black pile ; lower part with long white hair. Third antennal joint red or 

 reddish, the style black. Thorax with fine black erect pile on the front 

 part, and with whitish pile on the back part of the dorsum ; the base of 

 the scutellum with whitish pile, the remainder with long black pile. On 

 the pleurae, the fan-like fringe of pile in front of the halteres is mixed of 



