LEPTID.l'. 101 



opening, but al\\ ays embracing the wing-tip.* Discal cell al\v;iy.s 

 present, except in Hilarimorpha (non-Oriental) ; antei'ior cross- 

 vein near basal end of discal cell, always before its middle ; 

 4th longitudinal witb anterior branch forked, lower branch 

 simple ; posterior cross-vein nearly opposite anterior cross-vein ; 

 5th longitudinal forked at about its middle, the upper branch more 

 or less curved or angled at the point where it meets the posterior 

 cross-vein ; 6th vein complete. Two submarginal cells, 5 posterior 

 cells; anal cell open or closed; alulae of moderate size, generally 

 well developed, absent in Xylopuagin^ ; alar squamae rather 

 small, thoracic squamae absent, " but the frenum distinct and 

 developing a rather broadened membrane near the angle ; " 

 halteres distinct, stem rather long. 



The whole body in Lbptid.e is usually clothed with soft 

 pubescence, microscopically so ou the often apparently bare legs. 

 There are no bristles of a chaetotactic nature, though a few short 

 ones or bristly hairs often occur about the thorax, wing-roots, and 

 metapleurae. 



Life-liistory. The metamorphoses of many European species 

 are more or less known. f Larva amphipneustic, with parchment- 

 like skin, generally living under bark, in moss, or earthy matter, 

 predaceous on Coleopterous larvae and other soft-wood insects, 

 though some are aquatic. Twelve-segmented, including head, 

 which is exserted though small, long, pointed, the mouth-parts 

 very small ; the three thoracic segments with strongly chitiuized 

 dorsal areas, the prothoracic segment also hardened beneath ; last 

 segment with a strongly chitinized area on hinder part, with two 

 strong hooks, this ai'ea also bearing two spiracles. Abdominal 

 segments often with transverse swellings on lower surface, loco- 

 motion being effected by means of these, which take the form of 

 roughened intercalated spaces between the segments, though 

 Brauer affirms that true pseudopods exist in Atherix. 



The perfect insects are found usually in open woods and the 

 meadow-lands in their vicinity, or in marshy and soft places, 

 being fond of resting ou tree-trunks. 



With the exception of one or two North-American biting 

 species of Sijmphoromyia, which bite like Tabanid^, the Leptid.t: 

 are harmless to mankind. J 



The Leptid^ are rather closely allied to both the Steatiomyid.^ 

 and the Tabanid.^, but the former are easily known by the 

 crowding of the venation on the front part of the wing (except 

 in Beeix^'e) and by the shape of the discal cell, which is always 

 small, and seldom much longer than wide (except in XyJomyia), at 



* In one or two Eiii'opean species of Xylophagus, the lower branch of the 

 3rd vein may in individual specimens occasionally end barelj' above the wing-tip. 



t Atherix ibis, Xylophagus ater, Leptis tringaria, L. scolopacea , etc. 



X [Five species of blood-sucking Leptids have been described by White and 

 Ferguson from Australia and Tasmania, all belonging to the genus Spaniopsis, 

 White ; Trichopcdpus obscurus, Phil., baa been noted as a greedy blood-sucker in 

 Chile, and Leptis scolopacea, L., and L. sfrii/v^a, Mg., have been recorded as 

 biting man in France.— Ed.] 



