168 Annals Entomological Society of America [Vol. IV, 



hairs anteriorly and longer black hairs and bristles posteriorly, a tuft of 

 yellowish hairs before the scutellum in well preserved specimens, scu- 

 tellum with numerous yellow hairs and a few black bristles; legs mostly 

 yellowish red although usually there is a black or blackish area on the 

 front side of each femur; hairs of the legs yellow, bristles black; wings 

 with a pale brownish tinge, shadow in the first submarginal cell plainly 

 evident, a little more than a third of the width of the cell at the widest 

 part, ground color of the abdomen black, uniformly clothed with rather 

 short yellow hairs all over. 



The long hypopygium is clearly distinctive in this species. 

 It is nearly twice as long as in any other species I have seen. 



Numerous specimens from Clay County, Kansas, collected 

 by Prof. J. H. Schaffner. Aldrich catalogues it from Nebraska, 

 Missouri, Kansas, Connecticut and Florida. 



Promachus albifacies Williston. 



Total length 22 to 28 millimeters. Mystax and beard white, at 

 most only a few black hairs on the oral margin; palpi with many black 

 hairs and usually with some scattering white ones among them; rear of 

 the head with white hairs and a few black bristles above. Thorax 

 brown pollinose with the usual stripes above, a tuft of white pile in 

 front of the scutellum largely surrounded by black bristles, scutellum 

 with numerous white hairs and black bristles; wings nearly hyaline, 

 gray shadow in the first submarginal cell less than one-third as wide as 

 the cell at the widest point; legs largely black but somewhat variable, 

 often the femora are red posteriorly and the same may be said of each 

 tibia at base. Abdomen pure black in ground color, distinctly brown 

 pollinose on the venter and sides and on each side of each segment are 

 numerous white hairs which tend to reach across the dorsum and form a 

 very narrow hind border to the segment. Hypopygium small, short 

 and clothed above with abundance of silver white pile. 



The species is known from California, Colorado, Arizona, 

 New Mexico and Mexico. 



Promachus princeps Williston. 



Total length 27 to 32 millimeters. Mystax white with a few black 

 bristly hairs on the oral margin, beard white, palpi with numerous 

 black hairs and a few white ones, rear of the head with white hair and 

 some black bristles above; thorax gray pollinose, wings hyaline, gray 

 shadow in the first submarginal cell very narrow and usually not sharply 

 defined, legs approaching black, each femur posteriorly and each tibia 

 at the base more or less dark reddish; abdomen black in ground color, 

 gray pollinose on the sides and venter, with an area of white hairs on 

 each side of each segment and these tend to approach each other and 

 unite and thus form a band across the posterior margin of the segment. 

 The abdomen is somewhat variable when different specimens are 

 compared on account of the area covered with white hair. 



