1 93 



basal half, black on the apical half, but the proportionate extent 

 of each colour very variable : usually the fore femora principally 

 brownish yellow, in some instances wholly so. Tibi with 

 shining yellowish-white sheen ; or even silvery-white, on the 

 outer side, seen from above. Fore tarsi of male wholly black, not 

 widened, metatarsus barely as long as the rest of the tarsus ; the 

 whole tarsus a little longer than the tibire. Hind metatarsus of 

 male much widened and vertically compressed, three-fourths as 

 long as the tibia, distinctly longer than the rest of the tarsus, 

 yellowish on the basal half or two-thirds, the second tarsal joint 

 also sometimes yellowish at the base ; middle tarsi in both sexes 

 about as long as the tibise, the metatarsus as long as the rest of 

 the tarsus. In the female the whole fore tarsus is deep black, the 

 metatarsus and second joint much widened, metatarsus two-thirds 

 as long as tibia and rather less long than the rest of the tarsus, 

 the whole tarsus distinctly longer than the tibia ; hind tarsi as in 

 male and similarly coloured. All the legs bear more or less yellow 

 hair, but less conspicuously so than in S. aureohirtum. On the 

 tarsi the hair is deep black. Moreover, the pale parts in the less 

 of the male are very pale yellowish, almost whitish yellow. Wings 

 colourless, venation normal. Halteres yejlow, rather large and 

 thick. 



Length 2-2| millim. 



Kedescribed from two males (Bombay, 25. xi. 09), one of which 

 may now be considered the neotype of the species, only the female 

 having been previously described, and the whereabouts of the 

 tvpical specimen, even if still existing, being unknown. Also a 

 small series of females in the Indian Museum collection bearing 

 the following data: Darjiling, 12. viii. 09 (/. T. Jenkins] ; Kur- 

 seong, 10-26. ix. 09 (Lynch) Simla, 24. iv. 07 (Annandale) ; 

 Sylhet, 2.iii. 05, 18. iv. 05 (Lt.-C'ol. Hall); also three from Bamou 

 and Thadiar, 3500 ft., Tons Yalley in the N.W. Himalayas 

 (C. W. Rogers) ; Khasi Hills. Two other females in the same 

 collection appear to represent a variety with wholly black abdo- 

 men ; they come from Darjiling, 10. viii. 09 (Paiva), and Ukhrul, 

 Manipur/6400 ft. (Pettigrew). 



Type $ , location unknown. Neotype <$ in the Indian Museum. 



Dr. Becher originally described this species from Indian 

 Museum specimens labelled merely " Assam," and had only the 

 female before him, There are now no specimens authoritatively 

 named by him in the Indian Museum collection, so that the 

 whereabouts of the type female is unknown. The only males are 

 those described by me herein, from Bombay, and preserved in the 

 above collection, one of which in the circumstances may be 

 regarded as a neotype. The second male (not the neotype) has 

 the pale colour on the first abdominal segment much less distinct 

 than is usual. 



The fly is called the "potu" fly locally and it probably is 

 distributed along a considerable portion of the Himalayas, Assam 

 and the adjacent regions. In the north-western parts of India it 



