170 Oithorrhapha brachycera. 



17. H. bistriata Zett. 

 1842. Zett. Dipt. Scand. I, 340, 6, et 1849. VIII, 3015, 6, et 1859. 

 XIII, 5000, 6. — 1892. Strobl, Verh. zool. bot. Geseli. Wien, XLII, 145, 

 34. — 1902. Kat. palåarkt. Dipt. II, 248. 



Male. Vertex and frons velvet black, the latter narrowly greyish 

 just above the antennæ; epistoma dark grev; palpi dark, with long, 

 black hairs. Occiput duU black, with black hairs, which are present 

 chiefly at the eye-margin. Antennæ black, third joint relatively broad 

 at the base, and short. Thorax dark brown, sometimes rather dark, 

 with four black stripes, the median abbreviated behind, the lateral in 

 front, these latter broad. The dorsocentral and acrostichal bristles of 

 some length, black; the former uniserial, long behind, the latter bi- 

 serial. Further a humeral bristle, a posthumeral, about two noto- 

 pleural, a supraalar and a postalar bristle, all black, but they are 

 not much conspicuous, and besides there are other hairs at the sides 

 of the disc and in the præsutural depression. Pleura dark grey. 

 Scutellum with four black marginal bristles. Abdomen blackish brown, 

 black haired, with fine marginal bristles on the segments. Venter 

 dark grey, short-haired. Exterior genitalia of medium size, somewhat 

 compressed, with dark hairs, which are a little longer above. Legs 

 quite black or brownish black, dull, the hind femora shining on the 

 posterior side; coxæ greyish pruinose. The front femora 

 have somewhat long hairs on the posterior side; the 

 middle femora have fmer hairs on the anterior and 

 antero- and postero-ventral side; hind femora have fine 

 hairs above and below; the front tibiæ have short hairs 

 and some bristles above; middle tibiæ short-haired; hind 

 tibiæ with fine bristles on the dorsal side, and shorter 

 bristles on the antero-ventral side. Front tibiæ slightly 

 thickened towards the apex, metatarsi not much thickened, 

 a little thicker than the end of tibiæ, cylindrical, short- 

 haired; they are about three fourths of the tibiæ in 

 length, and nearly as long as the four following joints; 

 these latter are short, slightly or not longer than broad; 

 . the fourth joint on the middle tarsi as long as broad, 



f ti O' X 30 ^^^ other posterior tarsal joints longer. The hairs and 

 bristles black. Wings hyahne. Veins black or blackish; 

 the upper branch of the cubital vein originating at a somewhat 

 acute angle and somewhat diverging, slightly curved at the apex. 

 Stigma blackish brown. Halteres brown to dark brown. 



Female. Quite similar to the male. Front metatarsi simple, 

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



Fiar. G3. 



