NORTH AMERICAN DIPTERA 67 



tarsi chiefly dark red. Wings hyaline, costa beyond the tip of auxiliary vein con- 

 spicuously thickened ; furcation of third vein be^nd the base of second basal 

 cell. 



9. Abdomen deep black, with a posterior, rather narrow, pnllinose posterior 

 margin to each segment; the lateral margins of the segments more broadly pol- 

 linose, costa of wings simple. 



Two specimens, New Mexico (Gr. F. Gaumer). 



Erax latruiiciiliis n. sp. 



9. — Length 15-19 mm. Facial gibbosity prominent, the concavity below the 

 antennas short and rather deep. Gibbosity clothed chiefly with white hair, but 

 the oral margin and the middle of the convexity intermixed with black. Front 

 and face on the sides thickly clothed with whitish pollen. Antennfe black, the 

 first two joints with short white hair, and below usually with one or two black 

 bristles. Front and occiput with white vestiture, the former only with two bris- 

 tles, usually black, near the ocelli. Thorax strongly convex, somewhat com- 

 pressed in front, along the middle with a rather thin row of black pile and hair, 

 mane-like, beyond the suture it widens into a patch of longer black bristles, in 

 the middle of which in front is continued the row of black or white pile; on the 

 posterior part in front of the scutellum and on its dorsum there is sparser white 

 pile. The dorsu-m of the thorax in front on the sides with sparse short black, the 

 pleurse with very thin white, pile. The thoracic dorsum has brownish dust; the 

 pleurse rather thickly grayish dusted; bristles of the dorsuin and border of the 

 scutelfum moderately stout, mostly black. • Abdomen black, with white pile, not 

 long nor abundant; second, third and fourth segments on the sides, and rather 

 broad posterior cross-bands, white pollinose; fifth, sixth and seventh segments 

 wholly silvery-white pollinose, except a black spot in the middle of the fifth seg- 

 ment in front; hypopygium of medium size, shining black, chiefly black pilose, 

 the pile not long nor abundant. Femora black, legs elsewhere red. Wings 

 hyaline, the costa a little dilated beyond the tip of auxiliary vein; anterior cross- 

 vein beyond the middle of discal cell, the furcature of the third vein beyond the 

 •outer end of the discal cell. 



9 . Segments of the abdomen broadly grayish pollinose on the side and behind ; 

 wings not dilated on the outer costa. 



Hah. — Arizona, ^lontana. Twelve specimens (Professor Comstock). 



Eras furax n. sp. 



%■ — Length 16-19 mm. Head wholly clothed with white pile and hair, very 

 rarely a few black hairs near the ocelli. Face in profile only moderately concave, 

 densely white pollinose ; the pollen of the front a little yellowish. Thorax densely 

 gray pollinose, the dorsum often brownish; the median stripes not distinct, con- 

 fluent posteriorly ; dorsum in front clothed with very short black hairs, posteriorly 

 with sparse, slender, black, sometimes white bristles and shorter sparse white 

 hairs. Upper surface of the scutellum with sparse white hair, its border with 

 weak black or white bristle. Pile of the pleuriB wholly white, very thin. Dorsum 

 of the abdomen rather thickly grayish pollinose ; second segment on each side 

 rarely immaculate, usually with a brownish or brown spot, sometimes with a black 

 spot ; the spots on the third, fourth and fifth segments successively larger, nearly 

 always confluent on the fifth, and often confluent or nearly so on the fourth; fifth 

 segment with a narrow silvery hind border ; sixth and seventh segments wholly 



