182 Orthorrhapha brachycera. 



than broad, the apex somewhat rounded, turned dorsally; the arista 

 with the basal joint about as long as the apical Thorax dark green, 

 almost not pruinose, shining; scutellum a little hairy above, and with 

 distinct, black hairs at the margin. Pleura greenish, greyish pruinose; 

 propleura with very few, small, dark hairs and a black prothoracic 

 bristle. Abdomen dark green, not pruinose; it is clothed with short, 

 black hairs, and has short hindmarginal bristles, longer on the first 

 segment. Venter greenish, grey pruinose, with yellow hairs. Hypo- 

 pygium somewhat short, black, slightly pruinose ; eighth segment with 

 black hairs; on the ventral side of the hypopygium the edge is prolonged 

 into somewhat claw-like, black posterior lobes; at the end there are 

 two pairs of somewhat styliform inner lamellæ, the lateral with two 

 spines at the apex, the median with a dilatation in the middle and a 

 thin styliform apex; the outer lamellæ are yellow, they are narrow and 

 bent somewhat angularly downwards at the base; at the apex they 

 are split into some bristle-like teeth, the dorsal being the longest, and 

 there are long hairs at the margin. Legs yellow, front coxæ a little 

 greyish at the base, posterior coxæ grey with yellow apex; hind 

 femorawith a small, dark spot at the apex above; hind tibiæ darkened 

 to blackish in the apical third or half; on the anterior tarsi the apex 

 of metatarsus and the four following joints brownish or blackish, 

 hind tarsi black, the metatarsus much shorter than the second joint, 

 not much more than half as long. The legs have short, black hairs; 

 posterior femora with one preapical bristle; tibiæ with few and small 

 bristles; front tibiæ with only one small bristle above near the base, but 

 none below; middle tibiæ with four or five dorsal bristles in two rows 

 (two or three in the anterior row); hind tibiæ with two dorsal rows, 

 and a row of very small ventral bristles. Wings yellowish or light 

 brownish tinged; veins brown or blackish brown; discai vein with 

 a small bend and after it evenly converging towards the cubital vein; 

 axillary lobe small. Squamulæ yellow with a black fringe. Balteres yellow\ 



Female. Epistoma broader than in the male, but not broad, 

 greyish white. Antennæ shorter, third joint shorter than broad. 

 Wings with the discai vein a little less converging than in the male. 



Length 2,5—2,7 mm. 



H. nanus is not common in Denmark; Charlottenlund (the author), 

 Ordrup Mose (Stæger), Lyngby Mose, Faxe Ladeplads (the author). 

 My only dates of capture are in July. It was taken with the net in 

 the wood Charlottenlund on water piants in a small streamlet; at 

 Faxe Ladeplads it was somewhat numerously present at a ditch, flying 

 iow over the water, and the males were observed pursuing the fem åles 

 in the usual way. It was first detected in Denmark by Stæger, who 



