332 Orthorrhapha brachycera. 



are ^^k — ^^'9. It is found on tree-trunks, boardings and walls, often 

 in great number. 



Geographical distribution: — Europe down into Italy and further 

 into North Åfrica; towards the north to northern Sweden, and in Finland. 



l± M. truncorum Meig. 



1824. Meig. Syst. Beschr. IV, 67, 15. — 1843. Zett. Dipt. Scand. II, 

 452, 11, et 1849. VIII, 3055, 11 (Hydrophorus). — 1857. Loew, Neue 

 Beitr. V, 54. — 1862. Schin. F. A. I, 238. — 1877. Kow. Verhandl. zool. 

 bot. Gesell. Wien, XXVII, 68, 24. — 1903. Kat. palåarkt. Dipt. II, 340. 



Male, Vertex and frons greyish brown pruinose. Epistoma brown 

 below the antennæ, lower downwards the green ground colour is 

 more or less visible, and just at the transverse ridge it is whitish 

 grey ; below the ridge it is metallic green or bluish, just along the 

 sides is a narrow, whitish grey line. Palpi black. Occiput grey 

 pruinose; postocular bristles whitish, the uppermost dark. Antennæ 

 black, the third joint short, truncate; the arista almost apical, long. 

 Thorax slightly metallic green, grey pruinose, with three brown or 

 almost coppery stripes, the median often more green; the acrostichal 

 bristles short; the dorsocentral rows consist of four long bristles and 

 in front of theni a few very short. Scutellum with four bristles. 

 Pleura a little greenish or æneous, grey pruinose; propleura with two 

 or three yellow or brownish prothoracic bristles. Abdomen some- 

 Avhat metallic green, æneous or coppery, it is somewhat greyish pruinose, 

 clothed with short, whitish hairs, and with longer hindmarginal bristles 

 on the first segment. Venter somewhat greenish, slightly pale-haired. 

 Hypopygium small, black; the eighth segment greyish pruinose, with 

 pale hairs; the ventral lobes long, somewhat excised at the apex and 

 with some bristles; the outer lamellæ rather long and narrow, but 

 shorter than the lobes, also somewhat excised at the apex, and hairy. 

 Legs black, the knees reddish yellow; hind metatarsus about half as 

 long as the second joint, slightly excised at the base. The legs have 

 short, chiefly pale hairs; the bristly hairs on the anterior coxæ and 

 the bristle on the hind coxæ yellowish or sometimes brownish; the 

 hairs below the femora somewhat distinct, especially on the hind 

 femora, and these latter with longer, somewhat darker hairs above 

 on the basal half; middle tibiæ with a pair of bristles near the base, 

 and hind tibiæ here with a small bristle. Wings very slightly tinged; 

 veins blackish brown, the last part of the discai vein very slightly 

 curved, a little converging towards the cubital vein ; the last part of 

 the postical vein a little longer than the cross-vein. Squamulæ yellow, 

 the margin brownish, the fringe pale yellow. Halteres yellow. 



