222 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



cross-band from the apical x)ortion of tlie wing 5 another subhyaline 

 elongated spot at the distal end of both basal cells. Length G"^"". 



i?a&.— Denver, Colo., August 5 (P. E. Uhler); Utah ( J. D. Putnam). 

 This seems to be the common species in those regions. The coloring of 

 the body is variable, but the design on the wings will be easily recog- 

 nized. Five females and one male. It is not possible to identify G.fiil- 

 vasier with C. quadrivittatus Say, although it is rather singular that the 

 latter should never have turned up as yet in any of the western col- 

 lections. 



3. Chrysops proclivis n. sp. — Female. — Facial tubercles black on 

 the cutside of the dividing furrow only, thus leaving a broad fer- 

 ruginous interval between them ; cheeks black, shining ; the intervals 

 between cheeks, facial tubercles, eyes, rontal tubercle, and antennje 

 are filled out with stripes of pale fulvous pollen. Antennte black ; 

 underside of first joint reddish (sometimes the red is more extended). 

 Thorax black, moderately shining, clothed with yellowish pile ; a 

 stripe of gray pollen each side between the scutellum and the humerus 

 is more densely overgrown with yellow pile ; the same pile on the 

 pleur£e. Abdomen black; the sides of segments,! and 2 yellow, 

 leaving an elongated black square in the middle, slightly coarctate 

 on the hind margin of segment 1, and dovetailed on the hind margin 

 of segment 2, by the insertion of a yellow triangle; near the same 

 hind margin, 'ou each side, there is a more or less developed black 

 dot; segment 3 is black, with a yellow hind margin and three 

 more or less distinct longitudinal lines, breaking up the black in 

 four portions; segment 4 black, with a yellowish hind margin, some- 

 times expanded into a triangle in the middle ; the following segments 

 black, with narrow yellow margins; all the yellow portions, including 

 the hind margins, are beset with short yellow hairs. Yenter likewise 

 variegated with black and yellow. Front legs black ; base of tibiiE red- 

 dish : on the posterior pairs, the prevailing color is red, with more or 

 less black on the joints and at the base of the femora. Wings :— costal 

 cell and first basal cell brown, the latter with a small hyaline space at 

 the distal end crossed by a brown line ; second basal, anal cell, anal 

 angle, and fifth posterior cell hyaline; the cross-band reaches the hind 

 margin and fills out the fourth posterior cell ; apical spot narrow, en- 

 croaching but very little on the second submarginal cell; the hyaline 

 triangle enters the marginal cell, but is separated by a brown shade from 

 the costa ; distal margin of cross-band slightly protruding toward the 

 base of the second submarginal cell. Length 8-9-°™. 

 Hob, — Marin County, California. Four females. 

 As usual in species of this kind of coloration, the extent of the yel- 

 low on the abdomen is somewhat variable. 



