MANUAL OF NATURAL HISTORY. 257 



19. Family. — Mydas-Flies (Mydasidae). Antennae 



longer than head, 5-jointed, the two terminal 

 ones large, forming a club ; body elongated ; 

 wings with apical nerves running parallel 

 with posterior margin ; legs strong ; tarsi 

 with two brushes ; hinder thighs thickened. 

 Attack and devour other insects on the wing. 



20. Family. — Leaf-nosed Flies (Therevidae). Third 



joint of antennae ovate-conic, ending in a 

 small 3-jointed style ; palpi enclosed in oral 

 cavity ; proboscis ending in a pair of large 

 membranous labial lobes ; wings divaricate, 

 apical nervures running to extremity of wing; 

 abdomen conical. Found on trees ; often fly- 

 ing in swarms. 



2 1 . Family. — Raptorial - Flies (Tachydromiidae), 



Antennae apparently only 2-jointed, the basal 

 being very minute ; palpi incumbent, pro- 

 boscis short ; wings often with coloured bands, 

 without any large cell beyond the middle ; 

 fore -legs elongate, thickened, spined, rap- 

 torial. Run very rapidly on trunks of trees ; 

 rapacious. 



22. Family. — Spur-legged Flies (Leptidae). Palpi 



large, external, filiform or conical ; proboscis 

 large, fleshy, ending in two elongate labial 

 lobes ; antennae inserted near base of head, 

 third joint round or reniform ; wings divari- 

 cate, external nerve furcate ; middle and hind- 

 tibiae with two apical spurs. Wings often 

 spotted ; frequent sunny sides of trees. 



