352 THE CANADIAN ENTOMOLOGIST. 



Only two genera are known, distinguished as follows : 



Table of Genera. 

 Second submarginal cell receiving both recurrent nervures. 



Species black and yellow, not metallic ; clypeus flat, at apex 

 bidentate ; transverse median nervure in front wings not interstitial 

 with the basal nervure, but uniting with the median vein a little 

 before the origin of the basal nervure ; petiole of abdomen about 



twice as long as the metathorax Sceliphron, Klug. 



= Pelopoeus, Latr. 



Species metallic blue or violaceous ; clypeus anteriorly jdentaie ; 

 transverse median nervure in front wings interstitial with the 

 basal nervure ; petiole of abdomen not or scarcely longer than 

 the metathorax Chalybion, Dahlb. 



Subfamily IV. — Podiin^e. 



This subfamily comes nearest to the SceIip/iro?iince, but is at once 

 separated by the antennse being inserted on the anterior part of the face, 

 on or Just above an imaginary line drawn from the base of the eyes ; by 

 the much longer mesopleura, and by the absence of a large U-shaped area 

 on the metathorax or middle segment. 



Three genera are known, separated as follows : 



Table of Genera. 



First and second cubital cells each receiving a recurrent nervure, or the 

 first recurrent is interstitial with \.\\e first transverse cubitus 2. 



Second and third cubital cells each receiving a recurrent nervure, or the 

 secojid recurrent is interstitial with the second transverse cubitus 3. 



Second cubital cell receiving both recurrent nervures . . Podium, Fabricius. 



2. Second cubital cell wider than long ; hind femora, in both sexes, 



normal, the basal joint of their tarsi much shorter than their tibiae ; 

 petiole long or longer than the metathorax. . .Podium, Fabr. (pars.) 

 Second cubital cell longer than wide ; hind femora in 9 dilated at apex, 

 their tibiae shortened, the basal joint of their tarsi as long, or nearly, 

 as the tibiae; petiole shorter than the metathorax. Stethrorectus,Smith. 



3. Head in outline as seen from above, triangular, much produced 



behind, the temples oblique, but broad ; pronotum conically pro- 

 duced, longer than the meso- and meta-notum. . .Trigonopsis, Perty, 



