242 THE CANADIAN ENTOMOLOGIST. 



the apex of the mesonotum ; clypeus with 4 median teeth ante- 

 riorly ; pygidiimi bare ; hind tibite without special characters, 

 the tarsi of usual length, the basal joint hardly half as long as 

 the tibiae ; comb of front tarsi short. ( S un- 

 known.) Parapiagetia, Kohl. 



Face with slight, blister-like swellings in the middle appearing as 

 a strong transverse swelling ; no swelling on the upper frontal 

 part; the hind ocelli lying in a flat basis ; pronotum only slightly 

 impressed beneath the apex of the mesonotum, the collar long ; 

 metanotum as long, or nearly, as wide ; pygidial area almost 

 bare, with small bristles only at a])ex ; hind femora at basal 

 third beneath emarginate and with a tooth, often only with a 

 blunt process ; tarsi elongate, the basal joint of hind tarsi very 

 distinctly longer than half the length of the tibiae ; teeth of front 

 tarsal comb weak, short and slender Piagetia, Ritsema. 



4. Face ivithojit a swelling or fold along the inner eye margin ; pronotum 



more or less deeply impressed beneath the apex of the mesonotum ; 

 metanotum usually shorter than the mesonotum ; claws simple ; 



mandibles emarginate beneath 11. 



Face with a swelling or fold along the inner eye margin 5. 



5. Second cubital cell not petiolate, always sessile 6. 



Second cubital cell petiolate ; mandibles without a tooth within, emar- 

 ginate beneath on outer side ; front tibiae on outer side spinous ; 

 pygidial area bare, with the sides converging posteriorly ; legs, 

 especially the femora, stout ; hind tibiae not ridged ; ventral plate of 

 second segment without swelling Larraxena, Smith. 



6. Mandibles with an emargination on under side 8. 



Mandibles without an emargination on under side ; pronotum im- 

 pressed beneath the apex of the mesonotum, especially laterally ; 

 claws unusually long, simple 7. 



7. Mandibles with a subbasal tooth and a strong subapical tooth within 



( $ ) ; hind margins of the dorsal abdominal segments distinctly de- 

 pressed ; pygidial area ( ? ) and the dorsal plate with very distinct 

 scattered punctures, appearing (without taking into account the 

 scattered erect hairs) bare and shining ; hind tibipe not ridged ; front 

 tibise outwardly not spinous ; body and legs with long 



hairs Paraiiris, Kohl. 



Mandibles within, not far from the base, with one tooth in $, with 

 two teeth in % ; in the latter case the second tooth is distinctly 



