DIPTKBA. 313 



Dexia subcompressa, Mas. 



Nigra; caput argcnteum ; thorax cinereus ; nigro quadrivittatus ; ah- 

 domen compressum, argenteo hifasciatum ; alee cinerea, apice sub- 

 fusccB. 



Black, slender : head with a silvery white covering, clothed beneath 

 and behind with white hairs; fronlalia black, narrow, wideninj^ towards 

 the feelers; facialia without bristles; epistoma hardly prominent: eyes 

 bare: palpi black: feelers black; second joint ferruginous at the tip: 

 third linear, conical at the tip, not reaching the epistoma, more than twice 

 the length of the second ; sixth feathered with rather long hairs, almost twice 

 the length of the third : chest gray, with four black stripes, the outer pair 

 interrupted : abdomen compressed, slightly tapering from the base to the 

 tip, narrowjer than the chest, and full twice its length ; second and third 

 segments icith broad silvery bands along their fore borders : wings gray, 

 slightly clouded with brown near their tips ,- pra;brachial vein forming 

 an obtuse angle at its flexure, very slightly bent outward from thence to 

 its tip ; lower cross-vein with the two curves, the lower one deep and short, 

 the upper one long and slight : alulae whitish, with pale yellow borders : 

 halteres pale yellow. Length of the body 4j lines; of the wings 10 

 lines. 



East Indies. 



Dexia i^edesxris, Mas. 



Cinerea ; caput album ; thorax nigro quadrivittatus; abdomen apice 

 nigrum ; antennce fulvce ; pedes fulvi, validi, tarsis nigris ; ala: 

 sublimpidce. 



Black, narrow, with a cinereous covering : head tvith a white covering ; 

 frontalia deep black, ferruginous and widening towards the feelers ; facialia 

 without bristles; epistoma not prominent: eyes bare: palpi tawny: 

 feelers tawny ; third joint slender, linear, pitchy towards the tip which is 

 rounded, almost reaching the epistoma, about four times the length of tbe 

 second ; sixth black, bare, slender, more than twice the length of the 



