28 
hairs; bristles on hind tibiæ rather small but distinet. Wings yel- 
lowish, veins yellow or pale brownish; costa about 0,42 of the 
wing-length, costal divisions proportionately about as 11—4—3; 
costal cilia long; fourth vein almost not curved in its first part, 
curved upwards towards the end and a little recurved at apex. 
Halteres yellow or pale yellow. — Female. Antennæ somewhat 
smaller; abdomen without the characteristical pale colouring; from 
the female of halterata it will be known by the want of dense 
bristles on the hinder part of the venter and the longer costa. 
Length 1,2—1,7 mm. 
This curious species is not uncommon here, Copenhagen, Erme- 
lund, Holte, Tisvilde and Bogø south of Sealand 25 A>— 3 % in 1917 
and 1918 (Th. Mortensen, the author); it is sometimes taken on 
Windows. 
32. A. plurispinosa n. sp. tf. 
Likewise near halterata but besides by other characters dis¬ 
ti nguished by a more bristly hypopygium. 
Male. Frons broader than long, greyish black; inner bristle of 
lower row a little lower than the outer and equally distant from 
it and from the upper supperantennal bristle; supraantennals small, 
unequal, the lower about half as large as the upper; the upper 
supraantennals slightly more approximated than the inner bristles 
of the middle row, the lower direct beneath the upper, almost not 
nearer together. Antennæ a little above ordinary size, black, 
arista very short pubescent. Palpi yellow, of ordinary size and ar¬ 
mature. Thorax black, slightly shining; mesopleura bare. Scutel- 
lum with two bristles. Abdomen somewhat robust, black, with 
narrow pale hind margins to the segments; the lateral margins and 
the last segment rather hairy; venter yellowish brown, the hinder 
part densely bristly as in halterata. Hypopygium somewhat small, 
greyish; on each side there is an oblique row of four bristles 
which are directed downwards, and above and behind them some 
smaller hairs decreasing in size upwards; anal tube yellowish, 
dusky towards base. Legs light brownish yellow, hind femora 
brown at tip, with a few longish hairs below the basal part; brist¬ 
les on hind tibiæ distinet but fine. Wings yellowish, veins brown, 
second vein somewhat thick; costa 0 , 4 o of the wing-length, costal 
