1011] Promachus and Proctacautlnis 171 



pollinose with white hairs. Hypopygium rather wide and clothed 

 above with silvery hair, posterior ventral margin of the eighth segment 

 with black and white hairs. 



There is some variation among the different specimens. 

 The hair on the posterior part of the mesothorax may be largely 

 white, the legs may vary in the extent of the white or black 

 hair present, although the bristles are always black, and in the 

 male the margin of the eighth ventral segment may be furnished 

 entirely with black hairs. 



The distinct limitation of the black and white areas on the 

 dorsum of the abdomen so as to form bands, together with the 

 entirely black legs characterize the species. 



The male type and seven other males and females taken at 

 Albuquerque, New Mexico, by J. R. Watson. 



Promachus aldrichii n. sp. 



Total length 28 to 30 millimeters. Mystax and beard white, oecipito- 

 orbital bristles mostly black, palpi black with white hairs, only a few 

 black ones above. Dorsum of the mesothorax mainly with black 

 hairs, and bristles, but there is some rather long white hair on the scu- 

 tcllum and before it, prothorax gray pollinose, usual markings present 

 but they are not very plainly shown; legs black, clothed with black and 

 white hair and black bristles; wings clear hyaline, no shadow in the first 

 submarginal cell ; abdomen black in ground color, gray pollinose on the 

 sides and venter and clothed everywhere with rather short hair which 

 is almost all white, then being only a very few short black hairs on the 

 anterior dorsal part of each segment. In the male the posterior ventral 

 margin of the eighth adbominal segment is furnished with a fringe of 

 white hairs and the hypopygium is silvery pilose above. 



The most characteristic thing about the species is the uni- 

 form distribution of the white hairs on the abdomen so that 

 this part does not appear evenly banded as in nigripes. 



The male type and one female from Utah, and received 

 from J. M. Aldrich of Moscow, Idaho. 



Promachus minusculus n. sp 



Total length 24 to 2(i millimeters. Mystax and beard pure white, 

 palpi black with some black and some white hairs, occipito-orbital 

 bristles largely pale although there are always a few black ones inter- 

 mixed. Thorax gray pollinose, thoracic dorsum with the markings not 

 very distinct, clothed with black and white hair and black bristles, 

 bristles of the seutellum partly white and partly black, wings pure 

 hyaline, veins brown. Legs dark reddish in general coloration, femora 

 darkest anteriorly, tibiae red, tarsi nearly black, all the parts clothed 

 with reclining white hairs and black bristles. Abdomen rather dull 

 black in general coloration, venter, sides and posterior part of the dor- 



