SYNARTIIRUS SYSTENUS. 139 



coxa: black ; the former with black hairs and bristles. Fore feet yel- 

 low ; femora incrassated towards their basis, on the upper side with 

 a narrow brownish-black longitudinal stripe, reaching to the ex- 

 treme tip ; the under side is sparsely fringed with short black 

 hairs, and where these end, there are three black bristles turned 

 somewhat backwards. Fore tibine covered with thick, rather 

 coarse, but short hairs. Fore tarsi from the tip of the first joint, 

 which is about as long as the others, strongly infuscated. The 

 first and second joints beset .on the under side with short bristle- 

 like hairs ; pulvilli rather large. Middle feet yellow ; femora 

 thickened about their basis ;' the tibia3 have besides the bristle at 

 the tip only one on the upper side, not far from the basis ; the 

 tarsi are very much infuscated from the tip of the second joint. 

 Hind femora metallic-green with yellow tip, at the end of the 

 under side with a few black bristles. Hind tibia? yellow, only 

 sparsely bristled. Hind tarsi yellow at the basis, from the tip of 

 the first joint black-brown ; their joints decrease in length, the 

 first considerably longer than the second. The cilia of the whitish 

 tegulas show in most directions a brownish-black coloring, while 

 in some, they appear with a yellowish lustre. Halteres yellowish. 

 Wings grayish hyaline with brownish-black veins ; the posterior 

 transverse vein is straight and has a very steep position ; the last 

 segment of the fourth longitudinal vein shows upon its first third 

 an almost imperceptible flexure, otherwise it very little approaches 

 the third longitudinal vein, runs parallel with it and terminates 

 precisely in the apex of the wing. 



Hob. Middle States. (Osten-Sacken.) 



Gen. XVII. SYSTENUS. 



This genus, hitherto confined to European species only, may be 

 characterized in the following manner : First joint of the antennae 

 without hairs on the upper side ; the second joint transverse ; the 

 third large, longer in the male than in the female, in both sexes 

 broad at the basis, ending into a point, distinctly hairy ; arista 

 completely apical. Feet rather slender, in both sexes plain and 

 b'eset only with very few and short bristles. The first joint of the 

 hind tarsi without bristles and scarcely half the length of the 

 second. The sixth longitudinal vein of the wings distinct. The 

 abdomen of the male towards the tip and laterally much com- 



