13 
the same distance from each other as the inner bristles of the 
middle row or slightly more approximated, and the lower pair al¬ 
most not more approximated than the upper. Antennæ black, 
rather large, in profil reaching to the middle of the eye, arista 
very short pubescent. Palpi black, somewhat large, with long 
bristles. Thorax black; mesopleura bristly, the bristles of uniform 
size. Scutellum with two bristles. Abdomen black, the hairs at the 
hind margin of sixth segment distinet but not long, only at the 
sides longer. Hypopygium small, black, shining above at the very 
base; there are no bristles but downwards on the sides there are 
short, somewhat dense hairs and at the basal corners a little longer 
hairs; ventral plate dusky yellow, short, triangularly rounded ; anal 
tube of medium size, deep black. Legs quite black, only front 
tibiæ and tarsi a little paler; front tarsi not really thickened but 
distinetly stout, the three last joints as broad as long; the pulvilli 
somewhat large; hind femora on the basal half below with a fringe 
of somewhat short but rather dense and strong bristles, shortest 
but strongest towards the base; bristles on hind tibiæ distinet, but 
relatively small. Wings somewhat brownish tinged, veins dark 
brown to black, thick veins rather strong and also the thin veins 
somewhat strong, seventh vein nearly as strong as the others; 
angle at fork not small; costa well beyond middle, costal divisions 
proportionately about as 15—10 — 4; costal cilia long; fourth vein 
evenly and not mueh curved at the base and for the rest nearly 
straight. Halteres black. — Female. Similar to the male, antennæ 
smaller, front tarsi a little less stout; hind femora withouth fringe. 
Length 1,8 to fully 2 mm. 
Geel Skov 19 A—Vs 1915 (Th. Mortensen, the author), on fresh 
somewhat exsudating stubs of Acer; one male and eight females. 
15. A. hypopygialis n. sp. <f. 
This interesting species belongs to the group with subpleuralis 
Wood, but it is at once distinguished alone by its hypopygium. 
Male. Frons greyish black, rather broad but not twice as 
broad as long; bristles strong, inner bristle of the lower row about 
in the same height as the outer and nearer to it than to the upper 
supraantennal, these six bristles forming a nearly straight trans- 
