14S THE CANADIAN ENTOMOLOGIST. 



7. Females always apterous, and frequently, but not always, without ocelli; 



eyes variable 9. 



Females always winged, with ocelli ; eyes large, always extending to 

 base of mandibles 8. 



8. Abdomen sessile or subsessile, and often with a more or less distinct 



constriction between dorsal segments i and 2 ; front wings with the 

 stigma well developed, the marginal cell usually attaining the costa 

 at apex (rarely rounded or truncate at apex, with a slight space be- 

 tween Cosila and allies); hind wings usually without an anal lobe, 

 the cubitus either interstitial or originating beyond the transverse 

 median nervure ; very rarely originating before it; tibial spurs i, 2, 

 2; tarsal joints normal; eyes entire; ocelli normal; hypopygium 

 entire, not ending in a spine or an aculeus. Family XXXVIII. ,Cosilid£e. 

 Abdomen longly petiolate ; front wings with the stigma small, not well 

 developed, the second recurrent nervure subobsolete ; hind wings 

 bilobed, the cubitus originating far beyond the transverse median 

 nervure; tibial spars very long, straight; tarsal joints 2-3 in 9 

 dilated, deeply excised or lobed and filled with a membrane between 

 the lobes; eyes emarginate within; ocelli very large; antennae very 

 long, filiform, the joints with a bristle-like spine at 

 apex Family XXXIX., Rhopalosomidae. 



9. Middle tibiae with two apical spurs, rarely with one only, or none 



in some males. 



Middle coxpe usually slightly separated by a triangular or bilobed 

 projection of the mesosternum; females with the thorax divided 

 into three parts, the pygidium usually subcompressed or other- 

 wise formed, usually abnormal ; hypopygium in (^ most 



frequently armed Family XL., Thynnidae. 



Middle coxae contiguous, not separated by a triangular or bilobed 

 projection of the mesosternum, the latter being squarely trun- 

 cate at apex. 



Thorax in the $ divided into two parts ; pygidium normal ; 

 hypopygium in $ produced into a sharp aculeus which 

 curves upwards (very rarely simple, unarmed); hind wings 

 with a distinct anal lobe, the cubitus originating from the 

 apex of the submedian cell, interstitial with the transverse 

 median nervure, or rarely originating beyond 

 it Family XLI., Myrmosidae. 



