420 Syrphidae. 



Male. Vertex and frons blackish, slightly pruinose; episloma a 

 little greyish pruinose but with a broad middle stripe and likewise a 

 broad lower margin black and shining; jowls black. Vertex and frons 

 yellow-haired, the latter with black hairs in front; epistoma with not 

 dense, yellowish grey hairs. The epistoma is almost not hollowed 

 below the antennæ, nearly straight down to the central knob, which 

 is placed rather downwards about in the height of the lower eye- 

 margin; below the knob epistoma retreats but it is only somewhat 

 descending. Occiput black with a somewhat broad, greyish white or 

 silvery eye-margin up to above the middle; the hairs are blackish 

 below, yellow above. Eyes with dense, dark brown hairs. Antennæ 

 orange, third joint somewhat square but with the upper corner rounded ; 

 arista bare. Thorax black or brownish black, slightly shining, clothed 

 with dense, reddish yellow hairs. Scutellum yellow or orange with 

 reddish hairs. Pleura with long, dark brown or black hairs. Abdomen 

 black with a large, reddish yellow side spot on second segment, 

 occupying about the whole length at the margin and produced 

 triangularly towards the middle; third segment with larger or smaller 

 basal corner spots, often very small, almost or quite wanting; hind 

 margins of second, third and fourth segments yellow; abdomen is 

 duUish but shining on the spots and on a connecting line between 

 them, and on the middle of third and fourth segments; it is densely 

 clothed with longish, yellow hairs, darkest on second segment, paler 

 on third and fourth; on the hind part of second and especially on 

 third segment, sometimes also on fourth, they may be more or less 

 mixed with black hairs. Venter black with pale incisures, and with long, 

 pale hairs, dark in the middle at the hind margin of fourth segment. 

 Legs orange or yellowish red, anterior femora black to beyond the 

 middle or to nearer the apex, hind femora black at base or in the 

 basal third ; tarsi with the two last joints blackened ; hind tibiæ some- 

 what compressed and curved, hind metatarsi not dilated. Legs haired 

 as usual, the hairs on femora mainly black but more or less yellow 

 on middle femora at the apex and also above the hind femora ; these 

 latter with only a few bristly hairs below the tip; tibiæ yellow-haired, 

 on the posterior side of front tibiæ more or fewer black hairs about 

 the middle. Wings hyaline but yellowish at the base and along the 

 anterior margin, with a brownish cloud from the stigma down over 

 the base of the cubital cell. Stigma elongate, pale brownish. Squa- 

 mulæ blackish brown with a brownish or brownish yellow fringe. 

 Halteres brownish, the knob more orange. 



Female. Frons broad, black or bluish black, with a whitish 

 pruinose stripe at the eye-margins on each side of the antennæ; the 



