TIIEKEVID^. 295 



232. Systropiis flavipleura, sp. nov, 



d 2 • Difffi'iiig fi'om opMoneus in having the antenuse all black, 

 except the 1st joint which is indistinctly pale at base. Thoracic 

 markings as follows : — Dorsum black ; a diagonally-placed humeral 

 spot, its inner end bluntly pointed ; two small contiguous spots 

 immediately below its anterior end and touching the all-yellow 

 propleura ; an isosceles triangular spot on posterior corner of 

 dorsum connected by a narrow yellow line with a good-sized spot 

 just before wing-base. Front side of sternopleura bright yellow, 

 the colour continuing up to the 1st abdominal segment ; hinder 

 side of lower part of thorax yellow, with a median black stripe. 

 Sides of first four abdominal segments bright golden yellow, 

 remainder of abdomen dark brown. 

 Length, 22-28 mm. 



Described from two specimens in the British Museum, 

 The type J from the Lower Ranges, N. Khasi Hills, Assam, 

 1878 {A. Chennell). The second specimen is a $ and bears no 

 data. The Indian Museum possesses one specimen from Sikkim. 



Family THEREVIDtE. 



Head about as wide as thorax, nearly semicircular, neck short, 

 occiput slightly puffed out. Eyes bare, contiguous or subcontiguous 

 in S , wide apart in $ ; frons generally more or less produced 

 about base of antennae, and, with the face, bare or pubescent ; three 

 ocelli. Proboscis rather prominent, of moderate size, rather thick, 

 upturned; labella broad ; palpi unjointed. Antennae often showing 

 excessive or even monstrous development, approximate at base, 

 3-jointed,* with usually an apical style ; sometimes slender and of 

 considerable length (Ph)/cus) ; sometimes the 1st joint enormously 

 developed, longer than the head.f The only head-bristles are 

 postocular, and some at the extreme back of the head. 



Thorax subquadrate or slightly longer than broad, slightly 

 arched, generally with dense ]uibescence, which is normally 

 longer and thicker in the S ■ The macrochaeta? are : 2 to 6 pre- 

 sutural, 1 or 2 supra-alar, 1 strong postalar, 1 or 2 pairs prescutellar, 

 other dorso-ceutral bristles generally absent. Scutellum distinct, 

 semicircular, with four (rarely two) strong bristles on hind 

 margin. 



Abdomen of seven segments (rarely more) ; generally elongate- 

 conical and in most species with dense pubescence, whicli is more 

 erect in the 6 than in the $ ; no maerochsetae. Genitalia in c? 



* Some authors (as Mik) have claimed four joints in Thereva, Limdbeck 

 even admitting five, but thi.-i is incorrect. The iJrd joint soiuetimes has a 

 basal annulalion, which has tlie appearance of a joint, and the style has 

 sometimes the appearance of being divided. 



t Xestomyza and others ; no genus of this kind is Oriental. 



