98 SYRPHID^. 



with parallel sides, smooth, shining, with a Httle pale, microscopic 

 pubescence ; face in profile showing only the slightest concavity 

 above the central bump ; proboscis black. Antennce from 

 brownish-orange to _yellow ; upper side of first two joints blackish- 

 brown ; 3rd joint twice as long as broad, more or less brownish on 

 upper side and at tip ; arista bare, orange, tip black. Occiput 

 black, side margins with whitish tomentum and pubescence ; 

 upper margins yellow with yellow pubescence. In $ , frons 

 rather more than one-sixth of the head at vertex, widening 

 gradually to level of eyes where it is twice as wide ; a large square 

 black spot on vertex from eye to eye ; and a median, gradually 

 widening, very shining, black stripe of varying width extending 

 thence to two small shining black lunate caUi, barely raised above 

 level of frons, placed just above base of antennae. TJiorax : dorsum 

 shining ceneous-black from anterior to hind margin ; side margins 

 broadly bright yellow or yellowish-white from shoulder to behind 

 wing-base, where the colour narrows and dies away. Pleurae 

 shining black, with a large median yellowish-white callus from top 



Fig. 17. — Ischiodon scutellaris, Fabr., $ . 



to bottom of mesopleura, contiguous to a horizontal oval similar 

 callus on sternopleura, both spots bearing white pubescence. 

 Scutellum yellowish, the centre often more or less brownish. 

 Pubescence of thorax and scutellum greyish or pale yellow. 

 Metanotum shining black. Abdomen moderately shining black. 

 2nd segment with a large sulphur-yellow spot on each side, each 

 spot narrowed and rounded on its inner end ; the spots vary a little 

 in width, the median black line sometimes being very narrow or 

 indefinite. 3rd and 4th segments with a broad yellow band on 

 each, reaching sides, slightly arcuated and generally very shghtly 

 narrowed in middle, especially that on 4th segment ; the bands 

 are placed very near the anterior margin, leaving the base very 

 narrowly black and the hind margin more broadly so, though 

 occasionally the extreme hind margin may be pale. 5th segment 

 black, orange towards sides, or sometimes the greater part orange. 

 Abdomen with a little pale pubescence towards sides of 2nd 

 segment, rest of side margins with just perceptible pale pubescence, 

 that on remainder of dorsum microscopic. Venter mainly 



