228 Orthorrhapha brachycera. 



3. D. nigricans Meig. 

 1824. Meig. Syst. Beschr. IV, 33, 2. — 1857. Loew, Neue Beitr. V, 

 45. — 1862. Schin. F. A. 1, 187. — 1893. Strobl, Mittheil. Ver. Steierm. 

 1892, 142. — 1903. Kat. palåarkt. Dipt. II, 321. — Diaphorus obscurellus 

 Zett. 1838. Ins. Lapp. 706, 2, et 1843. Dipt. Scand. II, 492, 2, ^. — 

 Chrijsotus obscuripes Zett. 1838. Ins. Lapp. 705, 4 et, 1843. Dipt. Scand. II, 487, 

 8, ?. — 1874. Kow. Verhandl. zool. bot. Gesell. Wien. XXIV, 464, nota, et 476. 



Male. Vertex and frontal triangle black; the eyes are touching, 

 they have the facets in the upper half enlarged, and the two halves 

 are divided by a sharp line. Epistoma broad, grey. Palpi small, 

 dark yellowish. Occiput black, with black postocular bristles. Antennæ 

 black, third joint short; arista distinctly dorsal. Thorax black, slightly 

 greenish, it is brownish black pruinose, very slightly shining; in the 

 middle there are two narrow, greyish brown, longitudinal stripes. 

 Pleura greyish black. Abdomen somewhat short, black, with the light 

 from behind very slightly greenish; it is clothed with short, black or 

 brownish black hairs, longer at the sides, and it has hindmarginal 

 bristles, long on the first segment; the eighth segment has four long 

 and strong bristles. Venter black, somewhat greyish, with shortish, 

 black hairs. Legs black, tibiæ and tarsi blackish brown. The legs 

 have short, black hairs, front femora with somewhat long, bristly 

 hairs below, middle femora with short hairs, hind femora with some 

 bristly hairs at the apex on the antero-ventral side; front tibiæ with 

 about two small bristles above; middle tibiæ with one or two small 

 antero-dorsal, and a pair of indistinct postero-dorsal bristles; hind 

 tibiæ with few bristles in a dorsal row. Front tarsi with only some- 

 what short hairs above at the apex, and the pulvilli moderately large. 

 Wings brown tinged, most tovvards the anterior margin; veins blackish. 

 Squamulæ brownish black, with a black fringe. Halteres blackish. 



Female. Of more greenish colour than the male, thorax greenish, 

 brownish pruinose, abdomen dark green. Frons broad, brownish grey, 

 Epistoma blackish, greyish pruinose ; palpi a little larger than in the 

 male. Halteres with the knob yellow. 



Length 2,6 — 3 mm. 



D. nigricans is very rare in Denmark, only one specimen, a male, 

 has been taken on the same place as the preceding species, viz. in 

 Jutland at Laven near Silkeborg in August 1881 (H. J. Hansen). 



Geographical distribution: — Europe down into Italy; towards 

 the north to northern Sweden, and in Finland. . 



13. Argypa Macq. 

 Species of medium or somewhat large size, and of metallic green 

 colour; the males have in most species a beautiful, silvery pruinosity 



