154 THE CANADIAN ENTOMOLOGIST. 



SO long as the face, first joint very short, black ; second joint much longer, 

 yellowish ; third joint not twice as long as the second, blackish ; arista 

 black, almost naked, only very short pubescent ; vibrissas black, strong ; 

 proboscis black, stout ; palpi elongate, club-shaped, light yellowish or 

 reddish, bristly, terminal bristles usually black ; occiput convex, cinereous 

 brown, black bristly on the sides above, gray hairy below ; cheeks and 

 face lighter, sometimes light silvery yellow. Thorax cinereous brown on 

 the sides and below, pubescent on the sides ; darker above, not pubescent, 

 but with black bristles that are longer behind, and four longitudinal, 

 brown, dorsal lines, the outer two sometimes obsolete ; scutellum con- 

 colorous, with four black marginal bristles. Abdomen brownish cinereous, 

 black bristly on the borders of the segments, and black hairy on the 

 whole surface. Legs reddish or yellowish ; femora not much enlarged, 

 short bristly, usually largely cinereous ; tibiae with strong black bristles, 

 especially the hind pair ; tarsal claws black, moderately long. Wings 

 subhyaline, the costal portion slightly tinged with yellowish, especially near 

 the base, the anterior and posterior transverse veins clouded with black ; all 

 the veins blackish, at least toward the apex of the wing, delicate, except 

 the thickened first longitudinal and transverse humeral veins ; tegulse not 

 large, nearly circular, glassy, with a light brownish border and a long 

 fringe of light hair ; halteres yellowish. 



$ . Differs from the female in the front being narrower, but consid- 

 erably more than one-third the width of the head ; and the abdomen 

 thinly woolly or pilose, without bristles. 



Length of body 6 mm. ; of wing 6 to 6^ mm. 



Described from one female and three male specimens. District of 

 Columbia. 



Larva (full-grown). Dirty yellowish white, long, cylindrical, of equal 

 thickness, tapering slightly at the posterior extremity, more markedly so 

 at the head, composed of 12 segments including the cervical and anal, 

 each segment transversely wrinkled. Head small, corneous, one-half the 

 width of middle segments, irregularly very short ovate in outline from 

 above, light brownish above and below, with a dark brown margin 

 posteriorly both above and below ; above with two light dividing lines 

 diverging from the centre of the posterior margin outward to the antennae, 

 which appear as short, minute, raised points of a darker color, apparently 

 3-jointed ; mouth parts dark brown, nearly black. Second segment 



