170 



[Aogust, 



2 . FFOiitalia of almost equal widtli tLrougboiit, interfrontalia 

 continued almost to front of frons. Orbits, face, and jowls greyer 

 than in male. Thorax very dark grey, with a brownish tinge in 

 some lights, and a black patch over the base of each wing; humeri 

 and notopleural depression light grey. Abdomen dusted dark greyisli, 

 without any indications of dark patches. Bristling of legs as in the 

 male, but apparently 1-2 bristles alvrays present behind front tibiae, 

 and the auterodorsal bristle always present and distinct on middle 

 tibiae. Hind femora with a complete anteroventral row of bristles, 

 but only 2-3 long fine bristly hairs posteroventrally about the base. 

 Wings not conspicuously darkened. Squamae whitish. Halteres 

 deep yellow. 



I^ength about 5'5 mm. 



This species has been found in widely separated localities. Loch 

 ^Maree (Ross and Cromarty) and the Isle of Arran, in Scotland. 

 . Rydal (Westmorland), 13armouth (Merioneth), nr. Tarrington 

 (Hereford), and nr. Uunsford (Devon), occurring in June and .July. 

 It may vary in the number of postsutural dorsocentral bristles, and 

 to a certain extent in the chaetotaxy of the legs, but is always easily 

 recognised by its very black colour, subplumose arista, and darkened 

 halteres in the male. L. dispar Fin., a species very much like it, 

 ought to be found in Britain, and may be known by the presence of 

 a distinct bristle beneath middle tibiae, and the absence of a postero- 

 ventral row of long bristly hairs on hind femora, while the antero- 

 ventral row of bristles on hind femora is not continued back to the 

 base. 



24 (lo) Middle tibiae with no distinct bristle in front. 



25 (26) Arista subplumose. Large very dark species 



.... dejiigrata Mg. (v. above). 



26 (25) Arista at most pubescent. 



27 (28) Hind femora with a posteroventral row of bristles or bristly hairs, 



which are at least as long as femur is deep 



.... curata, sp. n. (v. above). 



28 (27) Hind femora quite short-haired posteroventrally. 



29 (oO) Tlio-rax, viewed from behind, with a distinct yellowish-grey or even 



li"-ht greyish patch in front of scutellum 



.... *11. vana Zett. 

 7iupta Zett. 

 J . Eyes very narrowly separated on frons, the narrow orbits 

 touching, the f rontalia at its narrowest part practically linear. Arista 

 verv distinctly pubescent. Thorax black, with a brownish sheen in 

 some hghts and rather more shiniug than usual, humeri and noto- 

 pleural depression grey ; the patch in front of scutellum varying from 

 brownish to grey, according to the point of view; tip of scutellum 

 also somewhat brownish-grey. Abdomen, viewed from behind, grey 

 or yellowish-grey; first segment very extensively darkened, second 

 sei;meut with a pair of trapezoid dark patches not broader than long, 

 third segment with similar bat narrower patches, fourth segment 

 somewhat darkened about middle. Legs usually with a tine bristle 



