12G [M^iy. 



and pointed at the end ; the colour of the two sexes is also different, 

 of the males being more or less testaceous, and that of the females 

 cinereous. 



1. First abdominal segment armed with setsB on the margin... 



1. geniculata, De Greer. 



2. First abdominal segment without setaB 2. cristata,^. 



S. aEXic'ULATA, De Geer. 



jlavifrons, Stseg., Schn., J" . 

 Antennae with the first two joints rufous, and the third black or grey ; palpi 

 yellow ; thorax grey, unstriped, clothed with rows of black bristles and numerous 

 short black hairs ; scutellum grey, witli apex often yellow ; abdomen in the male 

 yellowish-grey, often testaceous at the base and sides, with the apex and a longitu- 

 dinal dorsal stripe grey ; in the female it is entirely grey upon the dorsum, but 

 sometimes a little yellow underneath at the base ; the anterior edges of each segment 

 are encircled with a narrow pale ring in both sexes ; and there are two setae in the 

 middle of each segment near the edge, besides others on the sides ; the legs are 

 yellow, with the exception of the tarsi. Very common. 



S. CRISTATA, r. 



tacliinaria, Mgn., ^. 



cinerea, Mgn., Eond., $ . 

 This species, which may be at once known from the former by the absence of 

 setsB on the middle of the edge of the first abdominal segment, has the male very 

 similar to that of S. geniculata ; the two basal joints of the antennae are, however, 

 sometimes partly nigrescent ; the thorax is of rather a lighter grey, with pale 

 shoulders, and the abdomen is more flavescent and translucent. The female, which 

 seems to be less common than the male, is entirely of a pale bluish-grey colour, the 

 under-surfaee of the abdomen only being a little lutescent ; the femora are also 

 partly grey. Mr. Bignell sent me three examples of the latter sex (the only ones 

 that I have seen) in 1883, which were bred from Leucania littoralis. 



8 — THRIPTOCERA, Mcq. 



Gen. ch. — The little black and grey flies in this genus have the 

 eyes bare, and widely separated in both sexes ; the orbito-frontal 

 bristles in a double row in both males and females ; f acialia unarmed ; 

 cheeks bare ; antennae with both basal joints short, and the third from 

 three to four times longer than the second ; arista mostly bent or 

 elbowed, with the second joint elongated, but shorter than the third ; 

 abdomen oval, with the segments nearly equal in width, and only 

 armed with setae on the posterior margins ; wings with some of the 

 veins mostly setigerous, apical cross vein usually curved at the base, 

 outer cross vein seated midway between the inner one and the curve 

 of the fourth longitudinal vein ; and first posterior cell terminating 

 near the apex of the wing. 



