SYNOPSIS OF NORTH AMERICAN SYRPHIDiE. 185 



Helophilus groenlandicus. 



Tahanus groenlandicus O. Fabriciiis, Fauna Groenlaud., 208, 170. 

 Helophilus arctieua Zetterstedt, Ins. Lapp., 595,2; Dipt. Scaud, 678,2; Staeger, 

 Kroyer's Tidsskiif. N. R., i, 359, 24; Loew, Stett. Ent. Zeit.,vi, 119, 1843. 



Habitat. — Greenland, Lapland (Lw.) ! 



^ , 9 . Length, 11 to 12™™. Face below the autenu{« lightly excavated, 

 below only a little produced, the tubercle slight, in profile nearly per- 

 pendicular ; the lower line of the head forms with the occiput but little 

 more than a right angle; in the middle of the face with a shining black 

 stripe, which in well-preserved examples does not reach quite to the 

 antennae ; elsewhere on the face, as also on the greater portion of the 

 front, covered with whitish-yellow, sometimes somewhat darker, pollen; 

 cheeks shining black. Antennae black, immediately above their base 

 with a shining black spot ; a median stripe of the front and the region 

 of the vertex dark, nearly blackish ; pile of the front black, at the ver- 

 tex yellowish. Thorax opaque black, the usual light colored stri])e8 

 nearly whitish, the lateral ones only distinct at the humeri, behind in- 

 distinct; the median ones very narrow, linear, very distinct, in all the 

 specimens broken off' before reaching the scutellum; the pile of the 

 thorax is yellow, blackish only on the posterior part of the dark stripes. 

 Scutellum brownish, shining, in front with black, behind with yellow, 

 pile. Abdomen black opaque, only a little shining on the hind margins 

 of the segments, successively a little broader towards the hind part ; on 

 the second segment with a large, yellow, nearly a three-cornered spot on 

 each side, the inner angles of which are usually whitish and approach 

 each other moderately near; on the third segment there is on each side 

 a narrow, yellowish-wliitish curved semi fascia which terminates in a 

 small yellow spot in the anterior angle of the segment, which often in the 

 male has a greater extent ; on the fourth segment are seen the same yel- 

 lowish-whitish semi-fasciie but no trace of the yellow spots; on the last 

 segments the spots are smaller and less fasciate. The pile in front of the 

 hind margin of the fasciae is yellowish, from thence to the hind margin 

 of each segment blackish ; on the lateral margins the yellow pile ex- 

 tends somewhat farther back, the hind angles, however, always more or 

 less black ])ilose. Femora black, hind pair moderately dilated ; front 

 pair at the extreme tip brownish-yellow, on the hind pair there is a trace 

 of the same color on the under side of the tip; tibiae black, with the base 

 brownish-yellow ; hind pair moderately bent and not thickened at the 

 extremity ; tarsi black througliout. Wings hyaline with a grayish- 

 brownish tinge; stigma light brown, darker at its beginning; distal 

 portion of sixth vein moderately strongly arcuate, its terminal portion 

 strongly bent. 



Helophilus borealis. 



He}ophih(.s borealis Staeger, Kroyer's, Tidskrift, N. R., i, 359, 25. Loew, Stett. 

 Ent. Znt., vi, 1843, p. 12.3. 



ndbitat, — Greenland (Lw.) ! 

 5 . Length, 12 to 13™™. Face strongly excavated in profile below the 



