54 STEATlOllTIUiE. 



upper facets much larger than the small lower ones and generally 

 sharply delimited from them ; in § wide apart, with uniform 

 facets ; occiput with lower half considerably puffed out. Pro- 

 boscis retracted, with broad labella ; palpi rather inconspicuous. 

 Antenna? elongate, first two joints subequal, 3rd spindle-shaped 

 or peg-shaped, with four annulations and a two-jointed apical or 

 subapical bristle. Thorax oblong, rather arched, moderately 

 pubescent; humeri and posterior calli prominent; scutelluin with 

 two spines. Abdomen short and round, very arched, 5-segmented. 

 Legs simple, short, weak. Wings with normal venation; 3rd 

 longitudinal vein forked or simple ; 4th vein with three endings, 

 the 3rd often weak or absent ; posterior cross-vein absent, upper 

 branch of 5th vein forming part of lower side of discal cell, the 

 latter often indistinct : alulae well developed. 



Range. Europe, Asia, jNorth America, and one species from 

 Caffraria. 



Life-history. The larva lives in ^njnst^m-ud, among Conferva . 

 The flies frequent leaves and flowers in the sunshine near streams 

 and damp situations, where they are very active ; on sunless days 

 they settle on the underside of leaves near the ground. The 

 metamorphoses of several European species are well known. 



These insects are rather small, nearly bare, flies, generally of a 

 black colour with conspicuous yellow spots. 



0. signata is mainly a black species and 0. albomicans a yellow 

 one. 



27. Oxycera signata, sp. nov. 



6- Head: eyes with dense brown pubescence, contiguous for 

 a considerable distance, leaving vertical and frontal triangles 

 about equal in size, black ; former with black hairs and three 

 brownish ocelli on an elevated prominence ; latter bare, shining ; 

 face black, with a long oval patch of short snow-white pubescence 

 adjacent to the eye-margin on each side ; no postocular orbit ; 

 occiput black ; proboscis orange-yellow ; underside of head with 

 short white hairs. Antennae black, first two joints subequal, 3rd 

 as long as first two together, with four annulations and subapical 

 arista. Thorax shining black, with moderately dense brownish- 

 grey pubescence; a pair of widely separated, pale yellowish, 

 narrow, longitudinal dorsal stripes, not quite reaching either 

 anterior or hind margin of dorsum ; an elongate bright lemon- 

 yellow spot on each side of dorsum from prothorax up to the 

 suture, and a large orange-yellow 7 one on each posterior angle of 

 dorsum ; pleura? black, with whitish pubescence and a callus-like 

 long yellow stripe from prothorax (where its end is contiguous to 

 the stripe on the side of the dorsum immediately above it) to root 

 of wing. Scutellum bright lemon-yellow, with brown pubescence, 

 hind margin black ; metanotum shining black, microscopically 

 pubescent. Abdomen black, moderately shining, with micro- 

 scopic brown pubescence and a little white hair at sides of 1st 

 segment, which latter is narrowlv yellow at base ; a large subtri- 



