Winthemia. 371 



Tab. III, Fig. 59 (Chaetolyga). — 1907. Kat. palåarkt. Dipt. III, 233. — 1921. 

 Baer, Zeitschr. f. angew. Ent. VII, 142. — 1924. Stein, Arch. f. Naturgesch. 

 90, 6, 60, 5. 



Male. Frons above aboiit half as broad as the eye; cheeks less 

 than half the frons. Orbits and cheeks pale yellow, the former dark 

 upwards and black above; jowls greyish yellow; frontal stripe velvet 

 black. Ocellar and inner and outer verticals all somewhat small. 

 Frontal bristles reaching to the end of second antennal joint, small 

 upwards, all crossing. Vibrissæ scarcely ascending, Orbits and cheeks 

 with black hairs, the hairs on cheeks stopping a little before lower 

 end; jowls with dense black hairs. Occipiit yellowish grey, yellow 

 along eye-margin downwards, with bright yellow hairs. Eyes yellow- 

 hairy. Antennæ black, a little reddish at base of third joint, the 

 latter about thrice as long as second; arista thickened in nearly 

 basal half. Palpi yellow, darkened at base. Thorax black, somewhat 

 shining, yellow pruinose only on humeri and at the sides; two very 

 narrow, diill, black stripes are seen on the front part, outwards to the 

 acrostichals; sciitellum brownish, darkest at base. Thorax with 

 dense, black hairs. Two sternopleural bristles. Abdomen pale yellow, 

 and whitish yellow, almost silvery, or pale yellow pruinose; second 

 segment except a side spot, a narrow middle line, and most of fifth 

 segment above black; the middle line is broadest on third, very 

 narrow on fourth segment, the pruinosity on both sides of it grey; 

 hind margin of fourth segment black. Venter yellow, black along 

 the middle. Abdomen black-haired, with bristles only as a marginal 

 row on fourth segment and on apical half of fifth; at most besides 

 a pair of weak marginal on third segment. Fifth sternite cleft beyond 

 middle; upper forceps black, elongated triangular, incised at base, 

 with a strong, median longitudinal keel, stretching to near apex, 

 which is curved strongly inwards; arms of lower forceps red, triangu- 

 larly rod-like, not as long as upper forceps. Legs black; hind tibiæ 

 with a rather dense, anterodorsal row of equal bristles; claws and 

 pulvilli strongly elongated. Wings somewhat brownish tinged, especi- 

 ally at base and anterior margin ; veins blackish brown ; first posterior 

 cell distinctly open, ending rather near apex of wing. Squamulæ 

 yellow. H alteres brownish yellow. 



Female. Somewhat differing; frons broader, but scarcely as 

 broad as the eye; two upper reclinate frontal bristles. Thorax yellow 

 pruinose, with four black stripes, the median abbreviated behind 

 the suture, the lateral interrupted at the suture. Abdomen with 



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