124 EEPTIU.E. 



Genus LEPTIS, F* 



Leptis, Fabricius, Syst. Aatl. p. 69 (1805). 



Rhagio, Fabricius, Syst. Entoni. p. 761 (1775). 



Sylvicola (Sylvicolce) , Harris, Expos. Engl. Ins. p. 100 (1782). 



Genotype, L. scolopacea, F. (as Rhagio scolopaceus) • by definite 

 selection by Fabricius at tbe erection of Leptis. 



Head transverse, about as broad as thorax ; face very short, 

 quadrangular, bare, socketed between the large eye-margins (or 

 side-cheeks), the latter separated from the face itself by a deep 

 channel, and bearing long, rather conspicuous pubescence. Pro- 

 boscis prominent, thick, cylindrical, short, with distinct ribbed 

 labella ; palpi 2-jointed, distinct, with bristly pubescence, rather 

 drooping. Eyes bare, contiguous or subcontiguous in 6 , facets of 

 uniform size, or nearly so ; in $ well separated, the irons with a 

 shallow transverse suture a little above the antennae. Antennae 

 short, porrect ; 3rd joint short, conical or almost reniform ; arista 

 apical, rather long, fine, and upturned. Thorax practically 

 quadrangular, with rounded corners, slightly arched; pubescence 

 on the disc short, well distributed, rather bristly, with depressed 

 pile intermixed ; pleurae mainly bare ; prothorax and metapleurae 

 with rather long distinct pubescence. Abdomen nearly twice as 

 long as thorax, elongate-conical, with at least seven obvious seg- 

 ments ; pubescence fairly abundant, often rather bristly, but never 

 like adpressed pile, short except at the basal corners. Genitalia 

 in $ rather prominent, kuobbed, and blunt; ovipositor of $ jointed, 

 appearing like an 8th segment, with two pairs of ovate lamellae. 

 Legs rather long, especially the hind pair ; bind femora slightly 

 thickened; coxae rather long ; front tibiae without spurs; front 

 tarsi with "touch hairs'" below. f Wings as in Atrichops, but the 



* The name Leptis is of too old standing to be changed, and Yerrall 

 thoroughly explains all questions of synonymy concerning it (Brit. Flies, 

 v, p. 262). 



t In a paper by Mik (Wien. ent. Zeit. xviii, p. 230, 1899) it has been sug- 

 gested that there exists an organ of touch below the front tarsi in some genera 

 of Leptit>/e, Tabanid/e, Dolichopodidte, Empid^e, and some groups of Acalyp- 

 teata and Nematocera, in the shape of several long fine hairs, curved 

 towards the tips, which project beyond the normal short stiff pubescence and 

 the rather longer, regularly arranged, stiff bristles. He has noticed that some 

 species of. Leptis, when resting on leaves, sometimes support the body on the 

 four posterior legs and make a sweeping curved movement with the front 

 tarsi, as though brushing up minute particles from the surface, after which 

 they appear to hold the collected matter between the tarsi, and bending down 

 the head seem to imbibe it through the proboscis. These " touch hairs " 

 occur mainly below the front tarsi, though existing to a less extent on the 

 middle pair also, where they are not longer than the ordinary pubescence and 

 bristles, whilst they are absent on the hind tarsi. In Atherix marginata, F., a 

 not uncommon European species, these hairs are abundant, though almost 

 absent in A. ibis, F., whilst in other Leptid genera, including Ghrysopilus, 

 closely allied to Leptis, they are not present. They exist, however, in Tabanus, 

 and in this character Mik sees an additional kinship between Leptid2e and 

 Tabanid.b. Verrall gives a translation of this interesting paper (Brit. Flies. 

 v, p. 236). 



