2 AMERICAN HYMENOPTERA. 



Petiole shorter than hind femora, strongly trisulcate above, the sulci reaching 

 the apex ; no distinct furrow in the vicinity of ocelli trisulcus. 



4. Petiole above with three very strong sulci (both recurrent veins received by 



second subniarginal cell) ^• 



Petiole above not or scarcely sulcate, long, rather curved ; pygidium carinated 

 down middle (? except in fmcipes) 9. 



5. Front and clypeus with very dense, long silvery pubescence 6. 



Front and clypeus with sparse, short, silvery pubescence 7. 



(). Petiole slender, not much widened apically ; enclosure at base of middle seg- 

 ment without an inner triangular smooth area : head above with strong 

 separated punctures; abdomen elongate; mesopleurse punctato-striate 



throughout •* c«y liiidricus. 



Petiole robust, rather distinctly widened apically ; enclosure at base of mid" 

 die segment with an inner triangular smooth area; head not so strongly 

 punctured; abdomen ovate; mesopleurae not striated medially; poste- 

 rior surface of middle segment with almost regular transverse rugse 

 which terminate laterally at a vertical ridge regularis. 



7. Head with fine, separated punctures 8. 



Head closely and rather coarsely punctured, the occiput and front striato- 



punctate inixtus. 



8. Posterior surface of middle segment covered by large, deep, fossfe ; petiole 



robust, about as long as hind femora liiger. 



Posterior surface of middle segment covered by large, shallow fossie ; petiole 

 slenderer, a little longer tlian hind femora leucopus. 



9. Dorsulum coarsely striato-punctate 10. 



Dorsulum and head finely punctured ; face and clypeus with pale golden 



pubescence; antennae short, clavate ; legs reddish testaceous. fuscipes. 



10. Petiole thick, flat above, distinctly broadened apically ; longitudinal folds on 



dorsulum very distinct 11. 



Petiole rather slender, subconvex above, widened a little apically ; folds on 

 donsulum not very strong; nervurcs testaceous; mesopleurse with sepa- 

 rated punctures siinplicicornisi. 



11. Mesopleurae rugose-punctate; scutellum sculptured like dorsulum, coarsely 



striato-punctate ; base of tibiae and tarsi pale testaceous; nervures testa- 

 ceous Kolilii. 



Mesopleurae and scutellum with distinct punctures; nervures and legs en- 

 tirely black puiictatus. 



12. Ocelli forming a triangle, the space between hind pair never much more than 



equaling that between them and eyes 13. 



Ocelli forming a curved line, the space between hind pair much greater than 

 that between them and eyes (a recurrent vein received by the second 

 and third subniarginal cells) 22. 



13. Second and third subniarginal cells each receiving a recurrent vein ; legs and 



abdomen except petiole, red inoiiticola. 



Second subniarginal cell receiving "both recurrent veins 14. 



14. Petiole longer than the first segment; if not, then it is strongly trisulcate. 15. 

 Petiole at most as long as the first segment, generally shorter 21. 



\h. Petiole fully as long, or longer than the hind femora 16. 



Petiole barely as long, at any rate not longer than hind femora 19. 



