WILLISTON: NEW DIPTERA. 7 1 



when seen from behind, with a large oval spot, narrowly interrupted 

 by the suture, and a small spot behind; bristles moderately long, 

 two on the border of the scutelluni; the fan-like row of thin bris- 

 tles in front of the halteres white. Abdomen rather broad, thickly 

 light ochraceous pollinose, but very variable in different reflections, 

 showing a darker brownish color; before the middle of the second 

 segment and near the front of the two following segments with a 

 transverse row of finely punctulate spots; on the sides of the second 

 segment with a number of white bristles, on the following segments, 

 just in front of the smooth, bare, hind marginal band, with a row of 

 white bristles on each side, becoming successively shorter and extend- 

 ing further inward; hypopygium and ovipositor small, black or yellow. 

 Legs black with fine, close lying, white hair; a preapical ring on all 

 the femora, the front and middle tibiae, except the tip and a more or 

 less complete ring or spot on the basal third, and the base of the hind 

 tibiae, yellow; the metatarsi, except the tip, and the base of all the 

 joints also yellow. Wings hyaline, veins black; the large part of the 

 marginal and submarginal, all the posterior, discal and anal cells 

 densely microscopically pubescent, giving them, especially at the tip 

 of the wing, a distinct tinge; distal end of first posterior cell not as 

 wide as the end of the second submarginal cell, both branches of the 

 third vein sinuous. 



Length, 16-18 mm. 



New Hampshire, Massachusetts, Connecticut, South Dakota, and 

 Kansas. 



Asilus angustifrons. n. sp. 



Male. Face narrow, with a well-marked gibbosity on the lower 

 part, the concavity on the upper part being distinctly one-half of the 

 length of the face; thickly covered with light golden yellow pollen, on 

 the middle of the gibbosity with black, below and along the oral 

 margin with white hair. Antennae black, the first two joints with 

 black hair, t: e second more than half as long as the first, the third 

 about as long as the first two together; bristle as long as the third 

 joint. Front narrow, clothed with black hair and yellow pollen. 

 Occipito-orbital bristles chiefly white; beard rather abundant, silky 

 white. Thorax covered with dense silvery gray pollen; on the dorsum 

 ochraceous, leaving two dark brown stripes separated by a linear 

 interval and coalescent and narrowed before reaching the scutellum; 

 on each side with two spots separated, by the suture, and behind them 

 a small one; hair of the dorsum short, sparse, black, the bristles 

 moderately long but not stout; scutellum with two approximated bris- 

 tles; pleurae with white hair and i>ile. Abdomen black, not densely 



