NORTH AxMERICAN DIPTERA. 63 



is scarcely apparent, or only a brownish spot is present. Hypopygium densely 

 covered above with close-lyinsj silky-white pile. Legs black, with short white 

 hair and black bristles; the femora on their upper surface and the base of the 

 tibise red. Wings elongate, pure hyaline. 

 Six specimens, Washington Territory. 



Fromaclius albifacioj^ n. sp. 



'^ , 9- — Length 25-2S mm. Closely resembles I^. princeps,h\it differs in the 

 front, which is a little narrower above, in the third joint of the antennse being 

 more slender and spindle-sliaped, in the hair of the face more abundant (some- 

 times slightly tinged witli yellow) ; the dorsum of the thorax in the middle shows 

 three slender brown stripes, separated by two narrow grayish ones; the whole 

 thorax has a more reddish cast, and the bristles on the scutellum are more abun- 

 dant and sometimes intermixed witli more or less black pile. Abdomen as fol- 

 lows: first segment black, but little siiining, with short black pile, a little longer 

 on the sides, where there are some black bristles intermixed with long white pileJ 

 second segment black like the first, with short, not abundant, black pile, long and 

 more abundant toward the side in front, the sides of the segment rather broadly 

 chestnut-brown pollinose, extending further inwards behind (about a third of the 

 width of the segment;, clothed except in front with moderately long, recumbent 

 white hair; third, fourth and fifth segments similar, the black becoming less in 

 extent and more triangular in shape, so that on the fifth segment the brown pol- 

 linose, white-haired spots nearly touch each other at their tips; sixth segment 

 with only a small black spot; in the female the brown pollen does not extend so 

 far inwards on the posterior segments. Hypopygium smaller than in P. princeps, 

 thickly clothed above with reeumiient, silvery-white pile. Legs black, with white 

 pile (except on the hind tarsi) and black bristles; all the femora above broadly, 

 and the tibise, except the tips, especially of the hind pair, red, base of the tarsal 

 joints also red. Wings as in P. prtiiceps. 



Twenty-four speciuifn^, Arizona (^Prof. Comstock). 



Proiuacliiis BaMtafdii. 



Trupanea Ba.siardii Macquarl, iJipl. Exot. i, 2, 104, 30. 



Asilus laevinua Walker, Li^t, eu;., ii, Z'i2 (Type compared by Osten Sacken). 

 ^ Promachus PhUailelphicus Schiner, Verh. Z. B. Ver. xvii, 389 (Type compared 

 by Osten Sacken). 



Trupanea rubiyinis Walker, i ij'r. Saiind., 123 (Type compared by Osten Sacken). 



Asilus ultimus Walker. Dipt. Sauud., 136. — U. S. 



Promachus Bastardii Oaten Sacken, Cat. Dipt. 78. 



%^ , 9 . — Length 22-26 mm. Head rather thickly clothed with light yellow pile 

 and hair, the occipito-orbital bristles chiefly black (there are no bristles on the 

 face). Antennae deep brownish red, the third joint small and more or less blackish, 

 palpi chiefly black bristly. Tiiorax with light grayish and brownish dust on the 

 dorsum, the markings showing but feebly, on the pleurae more distinctly brownish 

 dusted; dorsum in front clothed with short black hair; behind, on the scutellum 

 and on the pleurse, with white lone; pile. Scutellum with numerous black bris- 

 tles, as also on the back part of the dorsum of the thorax. Abdomen black ; venter 

 deep densely chestnut-brown pollinose, which color encroaches on the sides of the 

 dorsal segments, forming a trapezoidal spot, becoming successively larger, and 

 which is clothed with white hair, bushy on the anterior segments, sparser and 



