Dolichopodidae. 193 



Length 2,5—3 mm. 



H. assimilis is rare in Denmark, I only know seven specimens; 

 Damhussøen, Ermelund, Bøllemosen, and on Langeland at Lohals (the 

 author); in Jutland at Mønsted near Viborg (Esben Petersen), and on 

 Bornholm at Hasle (H. J. Hansen); the dates of capture are ^^k — ^^/s. 

 In the coUection of our museum, of which Stæger's collection forms 

 the main part, the species stood confused with a couple of other 

 species ; at present there is only one specimen of assimilis left, a male, 

 which thus is the type-specimen, but Stæger mentions also the female. 



Geographical distribution: — Northern and middle Europe down 

 into Germany; towards the north to middle Svveden. 



15. H. aerosus Fall. 



1823. Fall. Dipt. Suec. Dol. 15, 17 (DolicJwpus) . — 1824. Meig. Syst. 

 Beschr. IV, 98, 43 (Dolichopus). — 1831. Stann. Isis 1831, 258,47 (Doli- 

 chopus). — 1838. Zett. Ins. Lapp. 711, 16 p. p. (Dolichopus). — 1842. 

 Stæg. Krøyer's Tidsskr. IV, 40, 35 {ærotus, lapsus) (Dolichopus). — 1843. 

 Zett. Dipt. Scand. II, 572,61, et 1855, XII, 4632, 61, et 1859. XIII, 5059, 

 61 (Dolichopus). — 1862. Schin. F. A. I, 210. — 1903. Kat. palaarkt. 

 Dipt. II, 316. — Dolichopus Dahlbomi Zett. 1843. Dipt. Scand. Il, 573, 62, 



Male. Vertex and frons grey, dusted; ocellar tubercle black. 

 Epistoma narrow, black; clypeus whitish grey or brownish. Palpi 

 dark. Occiput greenish, grey pruinose; postocular bristles black. 

 Antennæ black, scarcely as long as the head, third joint shorter than 

 broad, triangularly pointed, the lower margin convex, the point some- 

 what dorsal; arista very short-haired. Thorax dark green or some- 

 what æneous, slightly pruinose, shining; scutellura distinctly short- 

 haired. Pleura greenish, greyish pruinose; propleura with a few, 

 somewhat pale or darker hairs, and a black prothoracic bristle. Ab- 

 domen dark green or somewhat æneous, very slightly pruinose down- 

 wards; it is clothed with short, black hairs, and has hindmarginal 

 bristles, longest on the first segment, and also somewhat long at the 

 apex. Venter greenish, grey pruinose, with brown hairs, which are 

 longish at the base. Hypopygium quite as in assimilis., the outer 

 lamellæ dark brownish or black. Legs yellow, coxæ grey with the 

 apex yellow, the front coxæ may be a little more yellowish; tarsi 

 with apex of metatarsus and the four following joints black or brown ; 

 hind metatarsus considerably shorter than the second joint; very 

 often the front and hind femora have a more or less pronounced 

 blackish or brown stripe above (var. Dahlbomi). The legs have short, 

 black hairs, the posterior femora one preapical bristle; front tibiæ 



13 



