254 



Orthorrhapha brachycera. 



2. Halteres pale ; hind tibiæ with strong bristles 2. setigera. 



— Halteres dark; hind tibiæ without strong bristles 3. 



3. Wings hyaline, cross-veins distant 3. assimilis. 



— Wings brownish tinged or hyaline, cross-veins near to each 



other 4. 



4. Wings more or less brownish tinged ; the cubital vein curved 

 upwards at the apex and here thin, discai vein almost straight 4. exilis. 



— Wings almost hyaline; cubital vein curved downwards to- 

 wards the apex and terminating w^ith full thickness, discai 



vein with a curve behind the postical cross- vein 5. pusilla. 



1. D. aterrima Curt. 



1834. Curt. Brit. Entom. 397,3. — 1851. Walk. Ins. Brit. I, 136,1. — 

 1859. Loew, Neue Beitr. zur. Kennt. d. Dipt. VI, 40, nota. — 1903. Kat. 

 palåarkt. Dipt. II, 273. — Tachydromia niyritella : 1842. Zett. Dipt. Scand. I, 

 298, 32. — Drapeiis nigritella: 1903. Kat. palåarkt. Dipt. II, 274. — 

 Drapetis nervosa: 1859. Loew, 1. c. 37, 3. 



Male. Frons and vertex black; ocellar tubercle with two bristles; 

 epistoma black above, grey below; palpi grey with black hairs. 



Fig. 111. Antenna of D. aterrima. x 85. 



Occiput blackish above, grey downwards along the posterior eye- 

 margin; it has a pair of long, black bristles above. Antennæ black, 

 the second joint with a long bristle, the third joint 

 somewhat short ovate. Thorax black, shining, with a 

 greyish, somewhat adpressed pubescence; towards be- 

 hind there is a couple of somewhat longer, black dorso- 

 central bristles. There are two notopleural and a 

 postalar bristle, all black. Scutellum with two black 

 marginal bristles and some smaller hairs. Pleura black, 

 shining. Abdomen likewise black, shining, with short, 

 dark or brownish hairs. Venter of the same colour. 

 Legs black, trochanters, knees and the apex of the 

 tibiæ reddish ; tarsi reddish or brownish ; the front tibiæ 

 may be almost quite pale. The posterior tibiæ are on 

 the postero-ventral side prolonged beyond the insertion 

 of the tarsus in a tooth-shaped way, the tooth is reddish. 

 The front femora are somewhat thickened, and have a 

 few long hairs below, the hind femora have some 



Fig. 112. 

 D. aterrima, 



hind leg. x45. bristles below on the apical part; at the apex of the 



