348 Orlhorrhapha brachycera. 



row of short spines, which gradually become very short and dense 

 in about the basal half; on the postero-ventral side there is a row 

 of bristly hairs; the posterior femora and tibiæ have few, small, 

 variously scattered bristles. Wings a little greyish or brownish tinged; 

 veins black, the last part of the discai vein very slightly curved, al- 

 most not converging towards the cubital vein. Squamulæ yellow or 

 brownish yellow, with a white fringe. Halteres yellow, with the knob 

 dark above but with a yellow margin along the inner side. 



Female. Epistoma broader than in the male and much less nar- 

 rowed above. Front femora only slightly thickened, the spines below 

 a little shorter, after the interval two or three black spines of com- 

 mon shape, not flat, and no tubercle more apically ; the spines below 

 the front tibiæ more equal and less crowded in the basal half. 



Length 3,5 — 4 mm. 



H. litoreus is somewhat rare in Denmarkj Fure Sø, at Sorø, and 

 in Jutland at Skagen. My dates are ^W? — ^/s. It occurs at horders of 

 fresh water, and perhaps prefers such localities, but it is also found 

 at the coast. 



Geographical distribution : — Northern and middle Europe down 

 into Austria and Hungary; towards the north to middle Sweden, and 

 in Finland. 



5. H. bipunctatus Lehm. 



1822. Lehm. Prograram Hamburg, 41 (Dolichopus). — 1824. Meig. Syst. 

 Beschr. IV, 63, 7 {Medeter us). — 1843. Zett. Dipt. Scand. II, 442, 2, p. p., et 

 1849. VIII, 3047, 2. — 1862. Schin. F. A. I, 230. — 1903. Kat. palåarkt. 

 Dipt. II, 342. — HydropJwrus hinotatus Fall. 1823. Dipt. Suec. Dol. 3, 2. 



Male. Head higher than broad; vertex and frons blackish brown, 

 a little greenish at the sides. Epistoma broad, bright metallic green 

 above, brown below. Palpi brown. Occiput green or æneous, brownish 

 pruinose above, grey below; postocular bristles black, the hairs below 

 yellowish or reddish. Jowls absent. Antennæ black, third joint 

 roundish, pointed in front; arista longer than the antennæ. Thorax 

 dark olive or almost blackish, shining, with a slight greenish or blackish 

 violet reflex; along the margin it is dark brown pruinose; in the 

 middle there is a very narrow, brown stripe, and along the dorso- 

 central rows there are two stripes of small, whitish spots, about a 

 spot between each two bristles; dorsocentral bristles somewhat short, 

 numerous^ Scutellum with four bristles. Pleura greenish or æneous, 



Mik says (Wien. ent. Zeitg. VII, 1S8S, 142) that this species and borealis have 

 at most eight dorsocentral bristles, but I find in both species about nine to 

 eleven. 



