220 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



augle; annulate portion rather abru^^tly attenuated, as long as the body 

 of the joint. Thorax brownish-black: pleurae and pectus black, with 

 long black pile. Abdomen black, moderately shining. Legs black. 

 Wings slightly tinged with gray; costal cell and stigma brownish; 

 first posterior cell hardly coarctate. 



Sah. — Oaliforuia (H. Edwards). A single female. 



In its general appearance and coloring the species is not unlike T. 

 nigrescens, from which it is easily distinguished by the absence of browu 

 spots on the wings and other characters. It probably belongs in the 

 same group, especially if the shape of the head of the as yet unknown 

 male and the coloring of the eyes are like the same characters in T. 

 7iigrescens and pimctifer. 



7. Tabanus vv'NGIIF^e.r {Tabamis piincfifer O&ieu Sacken, Prodrome, 

 etc., ii, 453, 29). 



Sab. — Colorado, Utah ; Sonora, California ; not rare in the valleys of 

 the Coast Kange in June and July. 



Cheysops. 



The female specimens of the species described below may be tabu- 

 lated as follows : — 



Apex of the wing beyond the cross-band more or less infuscated; 

 first basal cell altogether, or to a considerable extent, infus- 

 cated : 

 Second basal cell infuscated on its proximal third or beyond : 



Prevailing color of the body black; palpi bla ik 1. noctifer. 



Prevailing color of the body brownish yellow ; palpi red- 

 dish 2. fulvaster. 



Second basal cell hyaline : 



The black facial callosities small, not converging anteriorly, 



separated by a broaJ, ferruginous interval 3. proclivis. 



The black facial callosities large, converging anteriorly, sepa- 

 rated by a narrow ferruginous interval 4. surdus, 



1. Chrysops noctifer n. sp. — Female, — Cheeks and the converge 

 ing facial and the large frontal callosities black, shining; between 

 them, the usual yellowish-gray pollen; antenuse black, reddish at 

 base. Thorax* black, shining, with vestiges of grayish pollen, form- 

 ing a faint, broad, geminate stripe anteriorly; scattered whitish pile 

 on the dorsum, more dense above the roots of the wings and on the 

 pleurie. Abdomen black; sides of segments 1 and 2 red, this color 

 occupying about one-lialf of the breadth of the dorsum; a faint, 

 appressed, whitish pubescence on the red ; similar whitish hairs on 

 the hind margins of the segments (in very well preserved specimens 

 these hairs form very faint triangles on segments 2 and 3). Legs 

 black; four hind tarsi brownish at base. Wings: — costal cell, two- 



