100 Syrphidae. 



O. elegans is rare in Denmark, I know only six specimens, four 

 males and two females; the males are taken in Jutland: at Horsens 

 (O. G. Jensen), Laven near Silkeborg, Frijsenborg (H. J, Hansen) and 

 at Fussingsø near Randers (Tryde); of the females one is taken in 

 Nørholm Skov at Varde (Kryger) the other is found in Westermann's 

 collection, labelled Sealand. The dates are from June to August. 



Geographical distribution: — Europe down into Italy; towards 

 the north to middle Sweden, and in Finland. It is upon the whole 

 a not CO m mon species. 



2. O. geniculata Meig. 



1830. Meig. Syst. Beschr. VI, 352, 16. — 1843. Zett. Dipt. Scand. II, 

 824, 9 et 1859, XIII, 6025, 9 p. p. — 1843. Loew, Stett. ent. Zeitg. IV, 

 273, 280, Tab. III, Fig. 25-27. — 1862. Schin. F. A. I, 273. - 1907. 

 Kat. palæarkt. Dipt. III, 16. — Chrysogaster fuscipeunis Zett. 1838. Ins. 

 Lapp. 615, 3. — Orthoneura elegans 1901. Verr. Brit. Fl. VIII, 187, figs. 

 197—198. 



Male. This species is very much like elegans. Head broader 

 than high; vertex equilateral. Frons rather flat, distinctly punctate. 

 Epistoma much broader than the diameter of the eye, widening down- 

 wards; it is a little more protruding above the transverse depression 



Heads of O. geniculata. 

 Fig. 35. Male. Fig. 30. Female. 



below than in elegans, and also the mouth edge is more protruding. 

 The silvery side dust spots larger, triangular. Frons with more con- 

 spicuous, white hairs. Antennæ brown or dark brown, shorter than 

 in elegans, third joint about three times as long as broad; arista not 

 much longer than the third joint; second joint with small, pale bristles 

 beneath. Eyes without band. Thorax a little more conspicuously 

 pale-haired, the stripes much less distinct. Legs with also tip of the 

 tibiæ a little yellowish. Wings somewhat tinged, with the upper 

 marginal cross-vein almost straight and perpendicular; middle cross- 



