Scenopinidae. 157 



longer than the lacinia; hypopharynx weak; labiiim with a short 

 basal part and rather large and broad labella about twice as long as 

 the basal part; in rest the proboscis is quite withdrawn. Thorax 

 rectangular, considerably longer than broad; no macrochætæ present, 

 Abdonien somewhat long, flattened above, with nearly parallel sides, 

 as broad as thorax; it consists of seven visible, not transformed 

 segments, the second being the longest; the segments have transverse 

 impressions on the dorsal side. The genitalia 1 have only examined 

 in situ with a lens ; they consist in the male, so far as I could ascer- 

 tain, of two broad lamellæ above and a considerably arched plate 

 below which is cleft in the hind margin; the female genitalia consist 

 of an eighth, normally developed segment and a small terminal part. 

 Legs somewhat strong, without bristles, but small apical spurs are 

 present on the tibiæ; sometimes the hind tibiæ are thickened, Claws 

 small ; two pulvilli, but no empodium. Wings with the cubital vein 



Fig. 48. Wing of S. fenestralis. 



branched and thus two cubital cells; the discai vein not branched, 

 the apical part curved up towards the end of the cubital vein, thus 

 the first posterior cell narrowed at the margin; as the discai vein is 

 not branched there is no i-eal discai cell, but this is formed below 

 in its whole length by the upper branch of the postical vein; the 

 discai cell is long; the first basal cell longer than the second; the 

 anal cell is closed at a considerable distance from the margin, Alula 

 developed; alar squamula slightly fringed at the margin, no thoracic 

 squamula, but frenulum distinct. In rest the wings lie parallel over 

 the abdomen, one quite covering the other, and they are also inclined 

 somewhat downwards on the sides, the fly thereby having a curious 

 appearance. 



I have not examined the developmental stages, but they have 

 been described several times, Bouché (Naturgesch. d, Ins. 1834, 46, 

 Tab. IV, Fig. 21— 25) describes larvæ and pupæ of fenestralis {senilis) ; 

 the larvæ were found in Polypori on Salix and other trees. Leon 

 Dufour described the pupa of fenestralis (Anal. d. la Soc. Ent. de Fr. 

 II, 8, 1849, 493, PI. 16, fig. IV). Frauenfeld (Verh. k. k. zool, bot. 

 Gesell, V^'ien, XIV, 1864, 65) bred fenestralis from larvæ found in a 



