Aphiochaeta. 289 



bristles. Thorax black, a little shining, with blackish brown to blackish 

 pubescence. Pleiira slightly shining downwards, Mesopleura with 

 well developed, uniform bristles. Abdomen black, a little greyish, 

 dull; it has sliort hairs on the hind parts of the segments, longer at 

 the hind margins; on the last three segments the hairs are rather 

 conspicuous at the hind margins and at the sides and they are especi- 

 ally long here on the sixth segment, Hypopygium somewhat large, 

 knob-like; it has on each side a number (about 8) of strong bristles, 

 placed partly below and partly in an ascending line; ventral plate 

 small, black and shining; anal tube not large, at most medium-sized. 



Fig. 90. Wing of A. Dahli S- 



blackish with a yellow apical part. Legs brownish or brownish black, 

 the front legs, especially the tibiæ, paler to yellowish; front tarsi 

 dilated, metatarsus the most, as wide as tibia; last joint blackish, 

 metatarsus a little dusky; hind femora with somewhat strong hairs 

 below in about the basal two thirds, strongest and densest at the 

 middle and here forming a conspicuous fringe ; hind tibiæ rather strong 

 in the apical half, the bristles distinct, but not large. Wings a little 

 yellow or greyish yellow tinged, veins brown, thin veins somewhat 

 strong, the seventh weaker; costa reaching beyond the middle of the 

 wing, 1 not double 2 and nearly equal to 2 + 3 or generally a little 

 shorter; costal cilia long; fork longish, fourth vein evenly curved, 

 a little more in the basal part. Halteres black. 



Female. Similar; antennæ a little smaller; front tarsi with the 

 four last joints not dilated, though somewhat stout, the whole tarsus 

 a little dusky; hind femora without special fringe below, but with 

 some longish hairs at the middle; wings generally clearer than in the 

 male. 



Length 1,8 — 2,2 mm. 



Remarks : I have seen a specimen of Dahli from the Museum in 

 Berlin, no doubt specifically identical with Becker's type; the spec- 



19 



