284 LEPTID.T. 



maculated wings and usually a particolored abdomen, re- 

 minding one of Clu-ysops. 



Head (fig. 189) semicircular, slightly narrower than the thorax and apparently 

 flattened because the lower part of the face seems to be tilted forwards and upwards. 

 Face with a quite bare rounded socketed epistoma lying between the large densely 

 hairy side-cheeks, but with all the space surrounding the antennae bare ; jowls and back 

 of the head bearing long and rather dense pubescence ; back of the head all pufied 

 out, most so on the lower part in the male but more equally in the female • frons 

 hairy from the vertex to the antennae in both sexes, and rather conspicuously so in 

 the female. Proboscis protruding, thick, with long oval sucker-flaps which bear 

 transverse stripes ; palpi two-jointed, almost as much produced as the proboscis, 

 upcurved on the basal third or more and then porrected straight forward. Eyes of 

 the male almost touching on the frons and with the facets not conspicuously con- 

 trasted in size, but those of the female widely separated ; quite bare in both sexes. 

 Antennae (fig. 191) short, well separated at the base ; basal joint cup-shaped and about 

 as long as the second, and both these joints bristly ; third joint kidney-shaped, being 

 deepened downwards, and bearing a long bare or slightly pubescent terminal arista 

 Avhich from the shape of the third joint appears to be dorsal. 



Thorax flatly arched, and bearing rather dense though short pubescence ; pleurae 

 with pubescence on at least the mesopleurae and the metapleurse, while the prothorax 

 bears similar hairs. Scutellum with pubescence similar to that on the thorax but 

 often longer and more erect ; metanotum concealed by the depressed scutellum, and 

 with its side humps bare. 



Abdomen conical or oblong, hardly twice as long as the thorax, with seven 

 segments, (lenitalia in the male with long prominent lamellas, but in the female 

 more flattened and shortly pointed at the tip. 



Legs moderate ; hind pair rather elongate, l)ut the front pair and especially the 

 front tarsi thin and unusually long ; front tibiae shorter, middle tibiae about equal, 

 and hind tibiae slightly longer than the tarsi ; front coxae rather long. Front 

 tibia; without apical spurs ; middle tibiae with two spurs of which the front one is 

 considerably the longer ; hind tibiae with two nearly equal spurs. Front tarsi with 

 " touch-hairs " beneath even though sometimes small and inconspicuous ; front 

 pulvilli and claws distorted in the male (fig. 190), but the posterior claws of normal 

 length. 



Wings with a venation rather similar to that of Chnjsopi/vs, the anal cell being 

 closed and petiolate, but the cubital fork is shorter and more widely open and more 

 bell-mouthed, the discal and small cross-veins placed at one-third from the base 

 of the discal cell, and the radial vein with an even curve upwards ; conspicuous dark 

 markings cover most of the wings but leave pellucid irregular incomplete bands. 

 Squamae (alar) moderate in size and with slight fringes. Halteres rather large. 



This genus is easily recognised by the remarkable coloration of the 

 wings; it is distinguished from Leptis by the closed anal cell and 

 reniform third antennal joint, from Chrysopilns by the two spurs to the 

 hind tibia3 and the remarkably distinct appearance, from Atrichojjs by the 

 hairy side-cheeks and frons in both sexes as well as the inore robust 

 build, and from Syiiiphoromyia by the two spurs to the hind tibise and the 

 closed anal cell. 



Athcrix is a very well-known genus, consisting of about sixteen species 

 which are recorded from all Europe, North and South Asia, South Africa, 

 and North America, but only three species are well known from the 

 European region, two of which occur in Britain. The metamorphoses of 

 A. Ibin have often attracted attention from the pecuhar habits of the 

 females, who lay their eggs in a dense mass formed of their own bodies. 



Synonym]/. — It is important that the type of this genus should be fixed, as some 

 confusion has arisen in the formation of subsequent dismembering genera. 



