Aphiochaeta. 363 



dark yellowish or yellowish brown. Thorax black, slightly shining, 

 with dark brown pubescence. Mesopleiira bare. Abdomen black, dull, 

 the very short hairs almost only visible at the hind margins of the 

 segments and a little longer at the hind margin of sixth segment. 

 Hypopygium small, greyish black, with small hairs on the sides; 



Fig. 107. Wing of A. crassicosla (^ . 



there is a flap-like, roimded, yellow ventral plate, reaching to the end 

 of the hypopygium; anal tube quite short, brownish or yellowish 

 brown. Legs yellow, the posterior legs, especially the hind femora, 

 darker to brownish; the hairs below the basal part of hind femora 

 medium long; bristles on hind tibiæ numerous, small and hair-like. 

 Wings strongly brown, veins brown, thin veins somewhat strong; 

 costa reaching fully to the middle, it is distinctly thickened from a 

 little after the humeral cross-vein to the end, the thickening being 

 similar to that in the female of tumida; 1 about equal to 2 + 3; 

 costal cilia long, but shorter than in tiimida; fourth vein fairly curved 

 in its first part, for the rest very slightly curved, nearly straight, 

 Halteres dark, dark brown to blackish. 



Fig. 108. Wing of A. crassicosta $. 



Female. Similar to the male; the hairs on the sides of second 

 and third abdominal segments somewhat distinct; hind femora with 

 longish hairs below as in the male; wings with the costa much broader. 



