564 Syrphidae. 



margin; they are long and a little stronger at the margin. Pleura 

 with yellow hairs in front and below, black behind, Abdomen dull 

 black with three dark yellow bands, narrowly interrupted in the 

 middle; the first band is about on the middle of the segment, the 

 second and third near the front margins, the third nearest; the third 

 band is often only indistinctly or not at all interrupted in the middle ; 

 the hind margin of the fourth segment is broadly orange, most broadly 

 in the middle, and the second and third segments have narrow, 

 orange, often indistinct hind margins; the abdominal bands are evenly 

 widened towards the sides as their hind margin slopes backwards 

 from the middle to the sides ; the bands are generally separated from 

 the sides, but the side margins may be yellowish on the last segments 

 and then here confluent with the bands. Abdomen is clothed with 

 short hairs which mainly follow the ground colour but are quite or 

 almost quite yellow on the whole fourth segment and long at the 

 hind margin of this segment; at the side margin the hairs are yellow 

 and a little longer than on the disc, and they are long at the basal 

 corners. Genitalia reddish with long, yellow hairs. Venter reddish, 

 with larger or smaller, black, transverse spots on the segments, first 

 segment black; the hairs are long and yellow. Legs red with about 

 the basal half or more of the femora and the last, or sometlmes the 

 two last tarsal joints black; on the front femora the black colour 

 often continued forwards below and on hind femora sometimes present 

 only on the anterior side; hind fernora slightly thickened and some- 

 what curved, hind tibiæ slightly curved ; the legs have moderately 

 long hairs, the femora, especially the hind femora, have long, bristly 

 hairs below ; the hairs vary in colour, on the femora from extensively 

 yellow, only behind front femora black, to all black; the hairs on 

 tibiæ yellow, often more or fewer black on the front side of middle 

 tibiæ, and on the hind tibiæ are some black hairs above and also 

 often on the front tibiæ. Wings more or less brownish or yellowish 

 tinged, especially towards the anterior margin; stigma dark yellow. 

 Squamulæ yellow with darker margin and fringes. Halteres with the 

 peduncle yellow, the knob blackish brown. 



Female. Vertex and frons broad, widening downwards, black 

 with a brownish pruinose cross-band a little above the antennæ; the 

 hairs black. Abdomen with the second and third bands generally not 

 interrupted, the fifth segment yellow with a more or less visible 

 blackish base; it has, like the hind margin of fourth segment, long, 

 yellow hairs. Hind femora not thickened. 



Length 13—17 mm. 



S. horealis is rather common in Denmark; Ordrup Mose, Bølle- 



