106 DIPTERA OF NORTH AMERICA. 



pectinated bristle, but otherwise resembling that species so much 

 that it is commonly confounded with it. Grayish-brown. Front- 

 opaque yellow near its anterior border, remainder yellowish-ferru- 

 ginous ; the ocellar triangle and the lateral stripes reaching 

 beyond the middle of the front are yellowish-gray. Antennae 

 yellowish-ferruginous, with the bristle dark brown, yellowish- 

 brown at the base, and having black hairs of moderate length. 

 Face yellow. Upper side of the thorax, with the exception of 

 the lateral borders, more brownish than gray, with darker brown 

 longitudinal lines, the two intermediate ones being darker and more 

 distinct, the lateral ones doubled behind the suture. Scutellura 

 flat, yellowish-brown, pollinose with grayish-yellow. Pleura? dark 

 brown, with a broad, more chestnut brown longitudinal stripe 

 running from the shoulder to the base of the wing, aud having 

 underneath a hardly distinct longitudinal stripe formed by paler 

 pollen. Legs rather dark brown, especially the anterior ones. 

 Tips of the fore and hind tibiae black ; tarsi blackish towards the 

 end. Wings grayish-brown, clouded with rather smoky brown 

 near the costal border ; transverse veins clouded with blackish- 

 brown ; the posterior transverse vein is slightly oblique and 

 straight. 



Ilab. Illinois. (Kennicott.) 



3. S. pnl)era, Loew. % — Fusco-cinerea, seta antennaruin breviter 

 plurnata, inetatarso antico albo, venis alarum transversis fusco-liinbatis. 



Grayish-brown, the antennal bristle brevi-plumose, the first joint of the 

 anterior tarsi whitish, and the transverse veins clouded with blackish- 

 brown. Long. corp. 0.21. Long. al. 0.21. 



Front opaque, sordid yellow near the anterior border, remainder 

 more yellowish-ferruginous, with the ocellar triangle and the late- 

 ral stripes brownish-gray, the latter reaching to the middle of the 

 front, the foremost bristle wanting. Antenme ferruginous, bristle 

 brown, with a short pubescence. Face pollinose with white. 

 Upper side of the thorax grayish-brown, with but little distinct 

 darker brown longitudinal lines. Scutellum flat, a little paler 

 than the upper side of the thorax. Pleurae rather dark brown, 

 pollinose witli whitish, without distinct longitudinal stripes. 

 Ground color of the abdomen almost brownish-black ; on each 

 segment there is a large triangular, not pollinose, spot, its tip 

 reaching as far as the hind border of the segment, the remainder 



