172 THE CANADIAN ENTOMOLOGIST. 



length ; front femora dilated at extreme base beneath or 

 with a slight tooth ; middle tibii\j with a short apical 



spur Ectemnius, Dahlbom. 



[Type E. guttatus, Dahlb.] 

 Scrobes normal, not bounded by a transverse carina superiorly. 



Front femora normal, witliout a tooth beneath 15. 



Front femora luith a tooth beneath beyond the base or near 

 the middle ; front coxae acute or with a tooth beneath ; 

 front tarsi depressed or subdilated ; head obtrapezoidal, 

 the temples broad and strongly convergent behind ; 

 antenna; with the third joint very long, the fourth slightly 

 emarginate at base beneath ; pygidium with a median 



sulcus Crabro, Fabr. 



Front femora witJi a tooth or dilate angulation at base be- 

 neath ; front coxae normal ; front tarsi depressed but not 

 very broad, nearly normal ; head obtrapezoidal, but the 

 temples not so broad or so convergent as in Crabro; 

 antennas with joints 3-6 emarginate beneath, the sixth 

 very strongly emarginate, the third usually elongate, 

 nearly as long as 4-5 united; mesopleura and metaihorax 

 coarsely striate ; middle tibial spur present but very 



short , Pseudocrabro, Ashm., n. g. 



[Type C. chrysarginus.] 

 15. Front trochanters armed with a spine or tooth beneath, the same 

 often clothed with hairs ; metathorax alveolate. 



Front tarsi normal, cylindrical ; middle tibi;>i with an apical 

 spur ; antennas simple, none of the joints emargin- 

 ate Hypocrabro, Ashm., n. g. 



[Type C. 10 maculatus. Say.] 

 Front trochanters normal, unarmed; metathorax not alveolate. 



Front tarsi abnormal, dilated, or at least flattened 16. 



Front tarsi normal, not dilated. 



Middle tibire without an apical spur ; thorax sculptured as 

 in Solenius ; abdomen smooth, impunctate or at most 

 sparsely, minutely or microscopically punctate. 



Antennie normal with the second joint much thick- 

 ened, none of the flagellar joints emarginate 



beneath Wetacrabro, Ashm., n. g. 



[Type C. Kollari, Dahlb. J 



