26 



The well-marked species of the Genus, easily known by the 

 four narrow black stripes on the yellow abdomen and by the cross-band 

 of wing not reaching beyond the postical vein in the female. 



Female. Head slightly broader than the thorax. Face 



ainly covered by the shining pale testaceous calli, the two facial' 

 caili leaving a narrow intermediate yellowish stripe which widens out 

 at its top just under the antennae, and which is pointed at its lower 

 end just below the facial deep pits ; at the outer sides of the bottom 

 part of each facial callus there is a deep blackish pit, and beneatht 

 that a fairly large yellowish dusted patch which usually extends te> 

 the eye margin and consequently separates the facial and buccal 

 calli, but the facial and oral calli are united on each side of the 

 middle yellowish line ; buccal calli shining black or blackish, very 

 small, transverse in a denuded specimen, somewhat inconspicuous, 

 and quite separated from the oral callus and hardly touching the eye 

 margin ; jowls below the buccal calli dusted with greyish yellow 

 and extending right across from the lower eye-angles to the mouth 

 margin ; pubescence of the face consisting of rather long whitish hairs;, 

 which leave most of the protuberant shining facial calli bare, as welll 

 as the oral callus, though even on its part a very few whitish hairs; 

 exist ; on the jowls and right across behind the mouth there are- 

 numerous longer whitish hairs. Frons nearly one-thirds the width 

 of the head, flat and nearly flush with the eyes, covered with greyish 

 yellow or orange yellow dust; ocellar triangle blackish or brownish 

 and colour slightly extending back to the occiput but only at the 

 middle ; frontal callus convex, blackish, usually testaceous about the 

 middle, sometimes entirely blackish or testaceous, transverse, with the 

 lower margin slightly angulated at the middle, extending almost from 

 eye to eye but not quite to the . n ennae because a doubly arched 

 orange yellow dusted margin extends across above the antennae, and 

 that colour extends all round the antennae and is connected with 

 the middle part of the face ; pubescence on the frons rathe abundant, 



