496 Syrphidae. 



Male. Vertex black, almost not pruinose; frons shinlng black 

 With a distinct, longitudinal furrow, it is only narrowly pruinose just 

 at the eye-margins; epistoma whitish pruinose with very broad, black 

 and shining lower lateral parts. Vertex has long, yellow hairs, frons 

 only a few pale hairs at the eye-margins; epistoma likewise with only 

 few, white hairs at the sides and on the eye-margins, the black lower 

 parts are bare; the epistoma is shaped as in the preceding species 

 but it is much more descending. Occiput yellowish pruinose, the hairs 

 long and white below, yellow above. Antennæ brownish, the basal 

 joints blackish. Thorax brownish or yellowish grey, a little shining, 

 densely clothed with long, erect, deeply yellow or tawny pile. Scutel- 

 lum yellowish pruinose, with siniilar hairs as on thorax. Pleura with 

 long, pale yellow hairs. Abdomen elongate, not broader than thorax 

 but distinctly longer, somewhat flat; it is dull brownish black on the 

 disc, shining bluish at the sides; the dull parts are shaped as broad 

 triangles with the sides sloping outwards towards the hind corners; 

 the first segment is grey pruinose at the sides; abdomen is clothed 

 with short, decumbent hairs, which are dark yellow or brownish yel- 

 low on the middle or on most of the dull parts, but black on the 

 shining side parts; the fourth segment is pale yellow-haired ; at the 

 basal corners of second segment is a conspicuous tuft of long, pale 

 yellow hairs; the sides are black-haired except on the yellow-haired 

 fourth segment. Venter black, grey pruinose, fourth segment shining; 

 it is clothed with long, whitish hairs. Legs black, all tarsi paler or 

 darker brownish or yellowish with the last or two last joints blackish ; 

 the hairs on femora somewhat long and dense, especially on the 

 posterior femora; on the anterior femora the long hairs on the posterior 

 side are white, but the short hairs on the anterior side darker, and 

 blackish above, and the hairs on hind femora somewhat similarly 

 coloured; the hairs on tibiæ are yellow, more or less mixed with 

 black, on the hind tibiæ are a few longer hairs below in the middle; 

 the anterior femora have a slight channel or flat space below the 

 apical part, and on the middle femora there are here fine, bristly 

 hairs; the hind femora have dense, somewhat bristly hairs below. 

 Wings yellow tinged and yellow at the base, with the same middle 

 and subapical clouds as in the preceding species, but more distinct. 

 Squamulæ brownish with a yellow fringe. Halteres yellow. 



Female. Vertex and frons moderately broad, widening down- 

 wards; vertex black and from it a middle line stretches down to a 

 large, black, shining space above the antennæ, the sides yellow pruinose ; 

 the hairs yellow, the space above the antennæ bare. Abdomen 

 broader than in the male, with a large, yellow pruinose spot at the 



