30 Orthon-hapha brachycera. 



is compressed, dilated dorsally and drawn out Into a point; it is like 

 the fifth joint brown or blackish; the middle metatarsus is much 

 longer, and the hind metatarsus about as long as the four folio wing 

 joints. Front coxæ with long, somewhat bristly, white hairs; posterior 

 coxæ with white hairs on the anterior and outer side. The front 

 femora are somewhat thickened at the base, and have about five very 

 long, white, somewhat curled hairs, and apically to them some shorter 

 hairs; for the rest the legs have short, chiefly brownish hairs, pale 

 below the femora; the hind femora have some long, pale hairs at the 

 base on the posterior side; the hind femora have a preapical bristle, 

 and the hind tibiæ small bristles on the various sides. Wings hyaline 

 or slightly yellowish ; veins brown ; the discai vein is doubly curved, 

 the lower branch of the fork quite short; the posterior cross-vein 

 curved very much outwards, situated about in the middle of the wing 

 and thus shorter than the part of the discai vein to the fork; the 

 part of the postical vein after the cross-vein short antl weak, not 

 reaching the margin. The wings have an incision in the hind margin 

 at the anal vein; the axillary lobe very large. Sqaamulæ yellow with 

 a blackish margin and a yellow fringe. Halteres yellow. 



Female. Epistoma not broader, or even scarcely as broad as in 

 the male. Front femora with about five strong bristles below; front 

 tarsi simple; hind metatarsus shorter than in the male. Wings with 

 the discai vein shghtly curved, the lower branch of the fork and the 

 last part of the postical vein longer, prolonged to or almost to the 

 margin; the posterior cross-vein curved much less outwards, situated 

 more apically and not much shorter than the part of the discai vein 

 to the fork; no incision in the hind margin of the wing, and the 

 axillary lobe smaller. 



Length 4 — 6,5 mm. 



S. nervosus is very rare in Denmark, we have only one male and 

 one female, from Westermann's collection, labelled Sealand, June 1824. 



Geographical distribution : — Northern and middle Europe down 

 into France; its northern limit is in Denmark. 



3. S. Wiedemanni Fall. 



1823. Fall. Dipt. Suec. Dol. 24, 2 (Leptopus). — 1830. Meig. Syst. 

 Beschr. VI, 360 (Psilopus). — 1843. Zett. Dipt. Scand. II, 625,2, et 1849. 

 VIII, 3105, 2, et 1855. XII, 4643, 2 (Psilopus). — 1862. Schin. F. A. I, 

 182 {Psilopus). — 1903. Kat. palåarkt. Dipt. II, 292. 



Male. Head broader than high; vertex and frons greenish grey, 

 the bristles black. Epistoma broad, white, flnely pubescent. Palpi 

 yellow, with whitish hairs and one bristle. Occiput grey, the post- 



