160 Orthorrhapha brachycera. 



below; the tibiæ are likewise short-haired without bristles, only the hind 

 tibiæ have bristly hairs on the dorsal side. Front metatarsi much thick- 

 ened, much thicker than tibiæ, straight below, arched above, about four 

 iifths of the tibiæ in length, and as long as the four other joints 

 together; third and fourth joint on all tarsi slightly longer than broad. 

 Wings hyaline or slightly greyish tinged. Veins black or dark brown; 

 the upper branch of the cubital vein originating with an acute angle, 

 slightly curved and much diverging; anal and axillary vein w^hite and 

 very weak. Stigma brown. Halteres black. 



Female. Quite agreeing w^ith the male. Front metatarsi simple, 

 about half as long as tibiæ, and as long as the three following joints; 

 hind tibiæ thickened in about the apical half, but not compressed. 



Length 3,5—5 mm. 



This species is at once recognised by the pluriserial dorsocentral 

 and acrostichal bristles, and it is also otherwise characteristic. 



H. maura is very common in Denmark; Lersøen, Amager, Char- 

 lottenlund, Bøllemosen, Lyngby Mose, Frederiksdal, Fure Sø, Geel Skov, 

 Tyvekrog, Nøddebo, at Nyraad near Vordingborg and at Skelskør; on 

 Falster at Resle; in Jutland at Nymindegab, Funder near Silkeborg, 

 Frederikshavn and Skagen. It is a somewhat early species, my dates 

 are ^-'/s— ^^/c It is generally seen flying in numbers above water, both 

 on commons, in fens and in woods, and it may then also be seen in 

 copula in the air, and generally with prey; I have taken it in copula 

 on ^/(5, ^Vc, and ^Ve; on the latter date I took it swarming over a 

 streamlet (Lyngby Aa) together with Ehamphomyia nigripes, which 

 latter v^as taken with the Hilara as prey. As mentioned under the 

 genus it is known to envelop the prey in a web. Zetterstedt records 

 it to the ^Wo. 



Geographical distribution: — Northern and middle Europe down 

 into France; towards the north to northern Scandinavia. 



11. H. interstincta Fall. 



1815. Fall. Dipt. Suec. Empid. 24, 17 (Empis). - 1842. Zett. Dipt. 

 Scand. I, 343, 10. — 1862. Schin. F. A. I, 115. — 1892. Strobl, Verh. 

 zool. bot. Gesell. Wien, XLII, 131, 22. — 1903. Kat. palåarkt. Dipt. II, 252. 

 — Hilara modesta: 1822. Meig. Syst. Beschr. III, 10, 17. 



Male. Vertex and frons velvet black, the latter with a greyish 

 brown triangle above the antennæ; epistoma grey; palpi greyish black, 

 with numerous long, black hairs. Occiput duU black or greyish, with 

 black hairs. Antennæ somewhat long, black, the style long. Thorax 

 blackish brown, very slightly shining, with three black stripes, abbre- 

 viated behind, the outer stripes appearing broader or narrower 



