62 Families and Genera of 



single row of bristles on each side ; no vibrissas on the border of the 

 mouth ; clypeus rather rudimentary. Only the middle tibiaj have 

 terminal spurs ; all tibi:e witli a small erect bristle on the exterior 

 side before the end. Ovipositor of the female not horny. 



Phycodromid^. 

 Thorax, scutellum and abdomen flat ; pleurae excised above the 

 coxaj. Front bristly ; border of the mouth hairy, witli no distinct 

 vibrissa. Legs stout, tibiie witli spurs and each witli an erect hair 

 or small bristle on the outside before the tip; the first joint of the 

 posterior tarsi not abbreviated; last joint of all tarsi enlarged, with 

 stout claws and long pul villi. Neuration of the wings complete; 

 auxiliary vein distinct in its whole length ; costa without bristles ; 

 basal cells not small. 



Heteroneurid^. 



Neuration of the wings complete, but the first longitudinal vein 

 rather short, an;l the auxiliary vein very much approximated to it ; 

 costa without bristles; basal cells small. Front with long bristles; 

 border of the mouth with a vibrissa at each side ; clypeus not devel- 

 oped ; palpi broarl and proportionately large. Legs, and especially 

 the tarsi, slender; middle and posterior tarsi with spurs; all the 

 tibiaj without erect bristle on the exterior side before the tip ; claws 

 and pulvilli very small. 



O P O M Y Z I D JE. 



Front with stout bristles above ; clypeus rudimentary ; border of 

 the mouth either pubescent or with long hairs, the foremost of which 

 sometimes forms a distinct vibrissa. Proboscis short ; palpi rather 

 small. Middle tibiae with a distinct, posterior tibiae with a very 

 short spur: the exterior side of the tibiie without erect small bristle 

 before the tip ; claws and pulvilli small. Wings elongated and nar- 

 row, with no bristles on the costa ; the axillary incision and alulae 

 are either wanting or very diminutive. First longitudinal vein much 

 abbreviated ; the auxiliary vein becomes obsolete before reacliing 

 completely tiie first longitudinal vein ; the latter emits, shortly be- 

 fore its end, towards the costa, a brancli, which may be considered 

 as the end of the auxiliary veiti ; basal cells small. 



S E P S II> /li. 



Head rounded; front bristly; border of the mouth more or less 

 hairy, the foremost hair often imitating a vibrissa ; clypeus rudi- 

 mentary ; proboscis short ; palpi evceedingly small or wanting. 

 Abdomen tapering towards the base. iNIiddle tibia' with diistinct 

 spurs ; claws and pulvilli small. Neuration of tlie wings complete ; 

 the auxiliary vein distinctly separated from the first longitudinal 

 vein; the two posterior basal cells ratlier large. 



D I O P S I D .^E. 



Neuration of the wings incomplete from the absence of the fore- 

 most of the two small basal cells ; the auxiliary vein very much 



