5 
of the posterior row directed more obliquely towards the apex; 
hind tibial bristles distinet but rather small. Wings clear or 
nearly so, veins brown or yellowish brown ; costa to near the 
middle (0,47), costal divisions proportionately as 11—7—2; angle 
at fork of medium size; costal cilia long, fourth vein evenly curved. 
Halteres yellow (in one specimen the halteres darkened and at the 
same time the anal tube being brown with only apex yellow). 
Length about 1,7 mm. 
The armature of the hind femora reminds one of Beckeri Wood, 
but besides by many other characters the present species is dis- 
tinguished already by the yellow halteres. 
Holte, Hillerød (Th. Mortensen), Ry in Jutland (the author), 
*%— 15 /7 in 1917 and 1918; five males. 
5. A. insons n. sp. tf. 
Likewise nearly related to albipennis Wood, but smaller and 
without the fringe below hind femora characteristical for that species. 
Male. Frons grey, about l 1 /*'times as broad as long; inner 
bristle of lower row somewhat below the outer and in about the 
same distance from it as from the upper supraantennal; supra- 
antennal bristles not large, approximated, the lower ones rather 
close to the upper and a little smaller. Antennæ black, arista dis- 
tinctly pubescent. Palpi yellow, ordinary. Thorax black; meso- 
pleura bristly, with two (in the single specimen) somewhat large 
bristles below. Scutellum with two bristles. Abdomen black. Hypo- 
pygium not large, partly withdrawn, but with some bristles on each 
side in an ascending line, and with a large, yellowish ventral 
plate, broadly rounded at the end; anal tube thin but of medium 
length, brownish with the apex yellow. Legs brownish, hind femora 
without any special clothing below, though with the short hairs 
more dense towards the base than usual; bristles on hind tibiæ 
small and delicate. Wings clear or nearly so, veins brownish ; 
costa 0,46 of the wing-length, costal divisions proportionately about 
as 4—2—1; costal cilia long; fourth vein evenly curved. Halteres 
yellowish, somewhat dusky. Length 1,2 mm. 
Holte 2 % 1917 (Th. Mortensen); one male. 
