51 



batches and upon almost dry land. Already SCHNEIDER (1914 p. 31) has pointed 

 out that the species winters as egg and ECKSTEIN (1918 p. 65) confirms this. GALLI 

 VALERIC (1909 p. 91 and p. 345) maintained that the eggs were laid in batches, EYSELL 

 (1908 p. 717; 1909 p. 203; 1910 p. 21) that they were laid singly; -the last-named author 

 is undoubtedly right. - - ECKSTEIN (1919 p. 100) has arrived at the same result as I 

 "dass die Weibchen die Eier erst in der 2 Halfte des Sommers ablegen". He has 

 further observed that the eggs are laid remarkably high up above the water level. 

 Geographical distribution: As LANG (1920 p. 86) remarks 0. cantans has 

 been so confused with 0. anmilipes that it is not possible to determine its range 

 with certainty. Most probably it is distributed over the whole of Europe. 



4. O. annulipes (Meigen). 

 Tab. IV. 



Description, Female: Proboscis moderate, subcylindrically flattened, the la- 

 bella? conically tapered; yellowish-white in the middle, black at base and apex, 

 brown hairs in the white part and white in the black especially at base. Palpi 

 stout, about one-fourth as long as the proboscis, clothed with blackish-brown hairs, 

 with scattered white ones especially at tip. Antennae with the joints equal, second 

 joint a little larger and thicker, yellow, the remaining joints rugose, brownish 

 pilose; tori subspherical, with a cup-shaped apical excavation, luteous, bright brown 

 and with a patch of small white scales on the inner side. Clypeus brown, conical, 

 prominent, nude. Eyes black. Occiput brown, clothed with curved, narrow, red- 

 golden scales and many slender, erect, black, brown scales, on the vertex; cheeks 

 clothed with flat, red golden, a little brighter scales; bristles bordering the eyes 

 black, a tuft of bright yellow hairs, projecting between the eyes. 



Prothorasic lobes elliptical, remote dorsally, blackish brown, clothed with 

 bright, yellowish-red hairs not brown as in cantans. Mesonotum dark brown, 

 almost black, very hairy, clothed with a uniform tomentum of red or red-brown 

 hairs either without any darker lines or paler scales at the margin or with lines 

 yellower and brighter than in 0. cantans. Scutellum trilobate, luteous, each lobe 

 with bright yellow bristles and curved pale yellow scales. Postnotum elliptical, short, 

 luteous. nude. Pleurae and coxae pale brown, clothed with elliptical white scales. 



Abdomen subcylindrical, flattened, posterior segment tapering; chitin uniformly 

 bright brown, very hairy, reddish-brown, with more or less obsolete bands of crea- 

 my white basal bands; no indications of apical bands on the last abdominal 

 segments; venter clothed with creamy white or yellow scales, mingled with some 

 black ones especially on the last segments and forming a continuous median stripe 

 in every segment with slightly lateral projections. Wings rather large, hyaline, with 

 a yellow tint; veins yellow, clothed with yellowish-brown scales; petiole of second 

 marginal cell shorter than its cell; that of second posterior cell almost of the length 

 of the cell; basal cross-vein almost its own length distant from anterior cross-vein; 

 fringe yellow, halteres entirely pale. Legs yellow, femora yellow with intermixed 



