PoUenia. 



135 



2. Thorax with four slight stripes; abdomen olive, whitish grey 

 pruinose with strong tessellations ; upper forceps with a 

 middle carina, elongate triangular, only cleft at apex 1. rudis. 



— Thorax with three stripes; abdomen bluish, whitish pruinose, 

 less tessellate; upper forceps without carina, narrowed in 



middle and cleft to the middle 2. vagabunda. 



1. P. rudis Fabr. 



1786. Fabr. Entom. Syst. IV, 314, 9 et 1805. Syst. Antl. 287, 16 (Musca). 



— 1822. Fall. Dipt. Suec. Muse. 48, 24 (Musca). — 1826. Meig. Syst. Beschr. 

 V, 66, 28 (Musca). — 1838. Zett. Ins. Lapp. 659, 22 et 1845. Dipt. Scand. 

 IV, 1339, 11 (Musca). ~ 1862. Schin. F. A. I, 586. — 1896. Pand. Eev. Entom. 

 XV, 151, 3. — 1907. Kat. palåarkt. Dipt. III, 526. — 1911. Kram. Abhandl. 

 Nat. Gesell. Gorlitz, 24, 40. — 1924. Stein, Arch. f. Naturgesch. 90, 6, 260, 2. 



— P. hisulca Pand. 1896. 1. c. XV, 152, 4. — 1907. Villen. Ann. Soc. Ent. de Fr. 

 LXXVI, 393. 



Male. Frons with the orbits touching above, a little protruding, 

 Orbits, cheeks and jowls brownish, intermediate triangle somewhat 

 reddish; frontal triangle black, somewhat greyish. Orbits and cheeks 

 somewhat densely hairy; jowls with black hairs anteriorly, yellow 

 behind. Occiput grey with yellow hairs and black 

 hairs behind postocular bristles. Antennæ black 

 or brown, the basal joints reddish, third joint 

 about twice as long as second, but varying to 

 more or less. Palpi black, sometimes brown to 

 yellowish. Thorax black, dull, slightly bluish 

 grey pruinose, more at the sides, and there are 

 four or indications of four black stripes. Thorax 

 has dense, fine erect black hairs, but colour and 

 hairiness is hidden under dense, felted, golden, 

 rarely paler hairs, which are, however, on the disc 

 often more or less completely lost; on pleura the 

 hairs form conspicuous tufts. Scutellum with 

 three or four marginal bristles on each side, 

 according to the lateral bristle being well developed or smaller to 

 disappearing. Abdomen olive, greyish or greyish white pruinose, the 

 colours forming shifting irregular tessellations; a black middle line 

 visible. Abdomen black-haired, hairs longest towards apex; on third 

 segment the marginal hairs long, on fourth a row of bristles and 

 fifth with bristles on apical part. Upper forceps with a high middle 

 carina, seen from behind elongated triangular with straight, slightly 

 converging margins, and thus evenly tapering to apex and here short 



Fig. 23. P. rudis, 

 forceps from behind. 



