EMPiD.ii:. 323 



occur in the legs in certain genera — Erupis and Rliamplwmijia, for 

 itistaiice, — in which in some species those of the 6 are provided 

 with knobs or characteristic spines or tnt'ts of hair, whilst those of 

 the 5 '11^ other species may be adorned with long scales forming 

 a conspicuous fringe. Tibial spurs sometimes present, never 

 large ; two fairly well-developed pulvilli and generally an empodium 

 of varying shape. Bristles of various sizes and specific value occur 

 on the legs of many species. Some species have raptorial legs. 



Winris usually of moderate size and normal shape, about as 

 long as the abdomen ; in one group n;irrow and markedly cunei- 

 form, the anal angle not distinguishable ; in certain genera 

 widened and considerably shortened ; practically bare, except for 

 a fringe of tiny bristles along some part of the costa ; in the large 

 majority of species unmarked, except for slight infnscations and 

 the stigma, when present. Venation exhibiting considerable 

 variety. Costa usually ending near apex of wings; auxiliary and 

 1st longitudinal veins of varying length, the former sometimes 

 shortened ; 2ud longitudinal vein long, simple or forked ; 3rd 

 ending before or after wing-tip, simple or forked ; 4th simple 

 -or forked, the upper branch often again foi'ked ; 5th simple 

 or forked, the lower branch often recurrent, meeting anal vein 

 at various angles ; anal vein present or absent, sometimes much 

 abbreviated. Anterior cross-vein present ; posterior cross-vein 

 always absent ; a discal cross-vein present or absent. One or 

 two submarginai cells, three or four posterior cells, discal cell 

 present or absent ; two basal cells ; anal cell present, incomplete, 

 or absent. Anal angle of wing prominent, moderately distinct, or 

 entirely reduced. Squamse generally absent, when present, small. 

 Wings covering the abdomen when at rest. 



The Empid.'E are a rapacious family, preying chiefly on small 

 soft Diptera and, to a less extent, on Lepidoptera, for which they 

 lie in ambush amongst leaves. Generally distributed, especially in 

 woods in moist situations. In some species aerial dances are 

 performed either by one or other sex or both jointly, copulation 

 ni these cases taking place in tlie air. Other species frequent 

 flowers. Some are fond of hovering in swarms just above small 

 ponds and streams, and mate on the surface of the water. I once 

 saw near London (at Esher, 1 think) a dense and regular streaui 

 of Il'dava iuaiini flying slowly backwards and forwards over a 

 brooklet, so that a single stroke of the net captured several 

 hundreds. 



Life-ldstory . Larva amphipneustic ; prothoracic spiracles small, 

 ftbdominal spiracles also small, placed on last segment, which is 

 more or less rounded, bearing a tooth-like wart on underside ; 

 ]2-segmented, cylindrical, tapering at each end; head small, 

 retractile, mouth-parts rather well developed, antennte small, no 

 eyes ; ventral side of most segments with transverse swellings. 

 The larva is carnivorous, living in the earth below leaves in 

 woods, or in decaying wood ; one European species of Hemero- 

 dromia apparently lives in the mud of 8treai))lets. Pupa free, 

 with pi'othoracic and seven pairs of abdominal spiracles. 



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