Empididae. 173 



shore they are, however, sandy. Stæger coUected it on Garex arenaria; 

 Zetterstedt records it from flowers of Salix. 



Geographical distribution : — Northei'ii Europe up to northern 

 Scandinavia; it is not known south of Denmark (see below), but it 

 occui's in England (according to specimens sent to me from Mr. Verrall). 



Remarks: This species cannot be pilipes Strobl (Verh. zool. bot. 

 Geseli. Wien, XLII, 147, 36), and the author himself also expresses 

 some doubt about it. Strobl's species is smaller, 2—2,(3 mm., with 

 long and strong marginal bristles on the abdominal segments; the 

 exterior genitalia are different, and the front metatarsi shorter than 

 tibiæ, which latter are not short, and the metatarsi are somewhat 

 long-haired above, but not with long hairs below. Strobl's species 

 must thus keep the name tanycMra Kow,, as already suggested by 

 the author. Of pilipes I have examined specimens which Zetterstedt 

 had seen. 



19. H. niveipennis Zett. 



1842. Zett. Dipt. Scand. I, 352,22, et 1849. VIII, 3017,22. - 1862. 

 Schin. F. A. I, 116. — 1892. Strobl, Verh. zool. bot. Geseli. Wien, XLII, 

 149, 37. — 1903. Kat. palåarkt. Dipt. II, 254. 



Male, Frons and epistoma grey; palpi yellowish or brownish, 

 with dark hairs. Vertex dark grey or grey. Occiput grey, or, when 

 seen from above, dark, with black, downwards paler hairs. Antennæ 

 black. Thorax light grey or almost bluish grey, sometimes with two 

 distant, slightly darker grey stripes, abbreviated behind. The dorso- 

 central and acrostichal bristles uniserial and biserial respectively, 

 black, the former long behind. Further a humeral bristle, a post- 

 humeral, two notopleural, a supraalar and a postalar bristle, all black. 

 Pleura grey. Scutellum with four black marginal bristles, the inner 

 considerably longer than the outer. Abdomen light grey, almost 

 silvery, with white hairs, and a little longer, fme, white bristles at 

 the hind margin of the segments. Venter similarly coloured, some- 

 times a little yellowish, short-haired. Exterior genitalia brownish or 

 darker, short and directed upwards, not obliquely forwards. Legs 

 brown or blackish brown, knees lighter; often the legs more light 

 brown, probably in immature specimens; coxæ grey. Middle femora 

 with bristly hairs on the anterior side; hind femora with fine hairs 

 above; front tibiæ extremely short-haired; hind tibiæ with short, 

 bristly hairs above. Front tibiæ slightly thickened towards the apex, 

 metatarsi somewhat thickened, a little shorter than the tibiæ, about 

 as long as the four foUowing joints, which are short, as broad as 

 long. The hairs are chiefly brownish. Wings milk-white. Veins 



