408 Syrphidae. 



in the basal half, or short-pubescent or apparently bare. Epistoma 

 broad and widening downwards; is is only slightly hoUowed below 

 the antennæ, sometimes nearly straight, the central knob not large 

 and the epistoma somewhat retreating below it and somewhat des- 

 cending; the oral aperture is rather large, the front mouth edge 

 curved upwards and the lateral angles somewhat drooping; the epi- 

 stoma is pale pruinose, in rare cases all over, but generally there is 

 a broader or narrower, black, shining middle stripe; also the mouth 

 edge is generally black, and the lower lateral parts are always black 

 and shining; the epistoma has somewhat long, erect or more decum- 

 bent hairs except on the middle stripe and the lower margin; the 

 ground colour below the pruinosity is generally yellow, but sometimes 

 black, Jowls somewhat broad but slightly descending, separated from 

 epistoma by a furrow. The oral cone is well developed and the pro- 

 boscis of some length. Clypeus is of the usual shape, the basal part 

 relatively short and the small, separated part at the base distinct. 

 Labrum (arbustorum) long and strong, semitubular, the median pro- 

 cess cleft to the base, beset with numerous pointed emergences, the 

 upper lateral process delicate, spine-like and pointed, the lower broad 

 with the inwards curved apex pointed; the processes are of equal 

 length; the usual row of small papillæ along the margin on the inside 

 present; hypopharynx as long as labrum, slightly attenuated outwards 

 but with the end cut, not pointed ; maxillæ with a knife-shaped lacinia 

 shorter than labrum, rather pointed and with the usual, microscopical 

 hairs in rows on the apical part; the palpus a little longer than the 

 lacinia, beset with microscopical hairs and with numerous shorter and 

 longer bristles, the long placed near the apex. Labium with the basal 

 part well chitinised, a little longer than the elongated oval, not broad 

 labella. Thorax rectangular or almost quadrate; scutellum black in a 

 few species, in the others yellowish or brownish and more or less 

 translucent; it has no fringe below the margin. ^ There are no bristles 

 present. Metapleura with dense, not quite short hairs. Abdomen 

 shorter or longer, somewhat narrowed towards the apex, on its 

 broadest part generally a little broader than thorax; in the male there 

 are four not transformed segments, the first the smallest; the fifth 

 segment present in the whole breadth, but very short and quite 

 hidden, the foUowing as usual lying on the left side, and the genitalia 

 of the usual shape, turned to the right; they are moderate or some- 



Girschner says that there is such a fringe, but that is erroneous ; the outermost 

 marginal hairs may (in some species) be curved somewhat downwards, but there 

 is no real fringe below the scutellar margin. 



