j(24 Syrpliidae. 



has below the margin a fringe of soiiiewhat long, downwards directed 

 hairs. Thorax has generally more or less distinct notopleural, supra- 

 alar and postalar brisUes and a number of scutellar marginal bristles, 

 and there may also be bristles or bristly hairs above on mesopleura; 

 the bristles are sometimes rather inconspicuous, especially the noto- 

 pleural and supraalar, and these may be wanting. In one group of 

 species there are no bristles on thorax or seutellurn, or in rare cases 

 (e. g. canicularis) only supraalar and postalar bristles. Metapleura 

 have short dense hairs. Abdomen more or less ovate or more parallel- 

 sided, in the female generally more ovate than in the male; like 

 thorax it has as a rule longer and more erect hairs in the male, shorter 

 and depressed in the the female; the ventral segments are well chiti- 

 nised. In the male there are four not transformed segments, the first 

 short; the fifth dorsal segment is small, unsymmetrical and hidden, the 

 fifth ventral is excised in the hind margin in the vvhole breadth, and 

 it is quite small and hidden. The genitalia are of the usual construc- 

 tion, the ninth segment with its appendages not large. In the female 

 there are five not transformed segments, the fifth somewhat small, 

 and three hidden, the last terminating with two small lamellæ. Legs 

 simple, hind metatarsi often a little thickened, sometimes more, rarely 

 also front metatarsi (in non-Danish species). Femora with long hairs 

 on the posterior side of the anterior femora and on the anterior side 

 of hind femora, the latter generally more or less setulose below from 

 short bristles; tibiæ short-haired. Glaws and pulvilli well developed. 

 Empodium small, spine- or bristle-shaped, finely hairy. Wings of com- 

 mon shape, somewhat various in length in certain species; middle 

 cross-vein well before the middle of the discai cell; the upper angle 

 at the upper marginal cross-vein more or less acute or rectangular. 

 Vena spuria very weak especially in its basal part. Alula well deloped. 

 Alar squamulæ with short, simple hairs, thoracai squamulæ with long, 

 furcately divided hairs. Plumula well developed, densely clothed with 

 somewhat short, simple or slightly branched hairs. 



Chilosia is a well characterised genus, distinguished by the black 

 epistoma, the separated cheeks (eye-margins), the weak vena spuria 

 and other characters; the specially distinguishing character is the eye- 

 margins as such are at most present below in some other genera 

 {Chri/sogaster, Platychirus)^ or when more developed {Ferdinandea) 

 the genus is easily distinguished by other characters. From Chryso- 

 gaster is ChUosia besides distinguished by the marginal fringe below 

 the scutellum. 



Not mucli is known about the developmental stages, especially 

 the larvæ. Reaumur (Mém. Ins. V, 1740, 65, PI. VIII, %. 4—5) men- 



