November, ISHo. 249 



6. Pericomi NuniLA, Meigen. 



PstjcJioda nubila, Meigen (1818) ; Zet., Dipt. Scand., ix, 3704 

 [?].— P. nubila, Schiner, Fn. Aust. Dipt., Bd. ii, ()3t [^]; v. d. 

 Wulp, Dipt. Neerland., i, 320, pi. ix, 17 (neuration) ; Etn., ante, 2nd 

 ser., vol. iv, p. 7, woodcut (neuration*), and p. 121 ; vol. v, pi. i, P. G 

 (detail). 



(J. Adorned on head, thorax, and legs, for erotic display. The greater part of 

 the long tuft of hair on the frons curves upwards between the antennce, but the 

 remainder spreads forwards. On the notuni, the short black Telvety pile in front of 

 the black transverse crest is frosted with white ; laterally, below the crest and above 

 the anterior coxa, is on each side a dense tuft of decurved black hair, glossed with 

 whitish ; the light ochreous transverse band extends backwards on the pleura below 

 the wings to subopposite the anterior basal cell. Abdomen hirsute, with very light 

 ochreous hairs in erect transverse rows, which, with change of posture, vary to 

 flaxen, and towards their roots to greyish-black, so that from certain standpoints 

 the hinder segments appear grey, with pale-tipped hairs, contrasting with the anterior 

 segments. Palpi black, glossed with whitish. Antennae more ornate than is usual ; 

 the verticils of hairs in this sex somewhat compressed (so that tlie hairs diverge 

 obliquely for the most part upwards and downwards), and as far as the 7th joint 

 loaded or intermixed with elongate scales, which, like the hairs, are denser and 

 longer on the lower side than above ; the hairs greyish-black ; the scales changing 

 colour, when shifted about, from white, yellowish-white, and light yellowish-brown, 

 to black. Legs black, glossed with white on the hairs and scales in the following 

 places : — in the fore leg, the extreme tip of the femur, the outer side (except at the 

 apical edge), fringes, posterior border of the inner side, and some scales in front at 

 the apex of the tibia, and in the tarsus the dorsum of the first joint down the 

 middle and externally, as well as at the base and apex on the inner side, the dorsa 

 of the 2nd and 3rd joints, also the scales at^the tips of these joints beneath, and 

 from certain standpoints the sole of the 2nd joint or of the Ist to the 3rd joints ; 

 in the hinder legs, viewed from the nearer side or from above, the tibial fringes, and 

 for a short space below the knee the long hair between them, the apical borders of 

 the tibia and first two tarsal joints, and (from above) the base of the Ist joint ; 

 viewed from the further side, the whole of the first two tarsal joints are glossed, 

 excepting the longer hairs of the 1st joint. Ungues ferrugincous. Apical fringe of 

 the wing yellowish-white, shaded with blackish-grey or black at the roots of the 

 hairs, from about the anterior radius to about tlic anterior pobrachial ; that of the 

 alulae, when erect, cream-colour or flaxen, shifting with change of posture to blackish ; 

 that at the base of the costa black at the roots, and glossed at the tips of the hairs 

 with white, yellowish-white or whitey-brown. 



? . Pubescence of the head and greater portion of the notum (nowhere velu- 

 tinous) light brown, with the tips of the hairs blackish-glossed, followed on the 

 metanotum by a transverse black-brown band, set off by the ligiit yellowish-brown 

 erect hair of the abdomen and fringes of the alulaj. In the wing the whitisli 

 exterior boundary of the region of bristling hair is marked on the posterior po- 

 brachial by only a few hairs at the most, which in both sexes are liable to be effaced. 



* Reduced by the engraver from the author's drawing, and rather forcshort. ned at the base 

 vf the wing. 



X 



