Pipiza. 79 



in the males; signata has smaller spots than noctiluca and less clouded 

 wings, also it is generally smaller; it has paler tarsi than the clear- 

 winged himaculata and notata; luguhris has generally no abdominal 

 spots, it has longer antennæ and more clouded wings than the four 

 first, and moreover paler tarsi than himaculata and notata; finally 

 austriaca is distinguished by the same characters as in the male. 



It will be seen, that the two species which are most difficult to 

 distinguish are notata and signata, just the two species about which 

 I am not sure with regard to the specific distinctness. 



1. P. luteitarsus Zett. 



1843. Zett. Dipt. Scand. II, 828, 2 et 1859. XIII, 6026, 2. — 1860. 

 Malm, K. V. och V. Samh. Goteborg Handl. VII, 63. — 1862. Schin. F. A. I, 

 265. — 1901. Verr. Brit. Fl. VIII, 165, 1, lig. 186. — 1907. Kat. palåarkt. 

 Dipt. III, 10. 



Male. Vertex black, slightly pruinose; frons and epistoma black, 

 but distinctly greyish or yellowish pruinose; epistoma high, the antennæ 

 placed above the middle of the head, and the epistoma is also broad, 

 more than one third of the breadth of the head. Vertex and frons 

 with yellovv hairs, but some few anteriorly on vertex and those on 

 the whole front part of the frons black; epistoma with yellow or 

 brownish hairs below, black above below the antennæ, or all black 

 or brownish black and in the latter case also the frons almost quite 

 black-haired. Occiput grey pruinose, with yellowish white hairs, longer 

 and more yellow at the upper eye-margin and here with some black 

 hairs; jowls yellow-haired. Antennæ short, black, third joint not 

 longer than broad, roundish, more or less ferruginous beneath, especi- 

 ally at base; arista scarcely as long as the antennæ, thickened in 

 more than the basal half. Eyes pale brownish-hairy. Thorax and 

 scutellum black or æneous black, slightly pruinose, shining and very 

 finely punctate; they are clothed with long, yellow hairs, longest on 

 scutellum especially at the margin. Pleura with long, greyish white 

 hairs. Abdomen not broader than thorax, with subparallel sides; it 

 is duU black, but shining and somewhat æneous just at the sides and 

 on the posterior half of the fourth segment including an elevation on 

 each side, and a similar shining elevation is found on each side of 

 the third segment; on the second segment there are a pair of yellow 

 or reddish yellow spots; they are Isolated, of transverse shape, broadest 

 outwards. Abdomen is clothed with yellow hairs, short in the middle 

 but long at the sides; at the basal corners they are whitish. Venter 

 appearing chiefly blackish grey, with somewhat long, pale hairs. Legs 



