46 Syrphidae. 



short, inserted at a little distance from the base of the third joint; it 

 is bare (with a few microscopic spinules), and it seems to be only 

 two-jointed, with a small, ring-like basal joint, Epistonia not hollowed 

 beneath the antennæ; it is arched or more or less keeled, especially 

 downwards, and there is a more or less pronomiced, not large central 

 knob in the middle or lower down ; epistonia always more or less 

 yellow, and it is hairy. Jowls very small, not going below the eyes, 

 with a small depression in front. The oral aperture long and narrow ; 

 the oral cone rather long. Clypeus somewhat linear, incised in front. 

 Proboscis likewise long and somewhat slender; labrum as long as the 

 basal part of labium, with a narrow median process, cleft in the apex; 

 the lower lateral processes broad, with the apex curved upwards, the 

 upper lateral processes thin and delicate. Hypopharynx pointed, semi- 

 tubular, the cavity upwards. Maxillæ knife-shaped, with a rather long, 

 linear palpus. Labium with the basal part longer than the labella. 

 Thorax about quadratic. Scutellum black or with the apex more or 

 less yellow, at all events in the female ; the margin with a row of 

 hairs below. No thoracai or scutellar bristles. Meso- and sternopleura 

 with long, coarse hairs; metapleura with short hairs. Abdomen with 

 about parallel sides; the segments have a more or less pronounced 

 transverse impression near the front margin. The first dorsal seg- 

 ment is larger or smaller, but not quite small ; its hind margin curves 

 forwards at the sides so that it is generally narrower than the fol- 

 lowing segment, the front corners of which stretch forwards. On the 

 ventral side there is a small chitinisation at the base, for the rest the 

 first and second segments slightly chitinised. In the male there are 

 five not transformed dorsal segments, but only four ventral ; the fourth 

 ventral segment does not stretch so far backwards as the dorsal; on 

 the ventral side, to the left lie the fifth to eighth small segments, they 

 are curved quite round to the right in an almost snail-shaped way ; 

 the ninth segment with its appendages rather thick, partly concealed 

 under the fourth, and all the transformed segments form a large ven- 

 tral knob. In the female the abdomen has five normal segments, the 

 sixth is generally also visible, but small, the rest more or less hidden. 

 Legs not long, hind metatarsus a little thickened. The legs mainly 

 short-haired, anterior femora with longer hairs on the postero-ventral 

 side, the hind femora on the antero-ventral side; tibiæ slightly fringed 

 above, especially the hind tibiæ. Two claws and pulvilli, and a small, 

 bristle-shaped, pointed and slightly hairy empodium. Wings with the 

 medial cross-vein before the middle of the discai cell; vena spuria 

 thin, but sharply marked, with a likewise sharply defined, dot-like 

 thickening below the origin of the cubital vein. Alula well developed; 



