208 THE SCOTTISH NATURALIST 



blackish brown, third and fourth veins convergent, outer cross- 

 vein straight, last portion of fourth vein about three times the 

 penultimate ; calyptra brownish, equal ; halteres yellowish. 

 9 . Close to a'erea in appearance, but more brownish grey in 

 colour, the middle stripe is more easily separated in outline 

 from the orbits than in a'erea, and at its broadest part is only a 

 little broader than the orbits ; the lower fronto-orbital bristle 

 stands close to the eye-margin, whereas in a'erea it is at the 

 middle of the orbit; the basal ventral mid femoral bristle is 

 absent or indistinct ; otherwise much as a'erea. 3 \ to 4 mm. 

 I have never met with this species. 



26. genitalis, Stn., £ . Black grey; eyes moderately separated; 

 frons in profile narrowly projecting, epistome and jowls distinct; 

 antennae shorter than the face, third joint about twice as long 

 as second ; arista bare ; thorax black-grey, shining, distinctly 

 grey dusted behind and at the sides; abdomen blue-grey 

 dusted, dorsal line distinct, anal organ inconspicuous; legs 

 black, all knees, especially the fore knees, distinctly yellow; 

 base of fore tibia broadly yellow ; a fine bristle in addition to 

 the preapical one on the apical half of the antero-dorsal surface ; 

 mid femora with a row of ten long bristles to beyond the 

 middle which decrease in size as they advance, the apical 

 portion with a row of twelve much weaker bristles which form 

 an almost continuous row to the tip ; basal ventral bristle very 

 long ; postero-ventral row much longer and doubled on the 

 mid-third, the shorter bristles longer than on the other surface ; 

 mid tibia very slightly thickened apically ; the pubescence very 

 short on the basal portion, but becoming longer and looser 

 towards the apex, bristling normal ; hind femora with a row of 

 bristles on the antero-ventral surface, the tip two or three the 

 longest, postero-ventral surface with the basal two-thirds armed 

 with a row of fine hair-like bristles ; wings greyish, third and 

 fourth veins nearly parallel, outer cross-vein nearly straight, 

 last portion of fourth vein two and a half times the penultimate ; 

 calyptra yellowish, unequal ; halteres yellow. 



$ . Pale grey, not shining ; frons very slightly convergent 

 behind, middle stripe thickly dusted, hardly separable in colour 

 from the orbits, orbits nearly parallel-sided and as broad as the 

 middle stripe ; thorax and abdomen pale grey dusted, without 

 a distinct gloss ; legs black-grey, dusted, coloured as in the £ ; 

 the extra bristle present on the fore tibia ; mid femoral basal 

 bristle strong; mid tibia with a ventral bristle beyond the 



