AMERICAN HYMENOPTERA. 131 



Section I. — Abdomcji black or blue, without pale bands or spots exceptt sometimes on 



apex of first or last segments. 

 Posterior legs black, their tibiise immaculate. 

 Coxal scopa distinct. 

 Apex of abdomen immaculate. 

 Wings fuliginous. 

 Postpetiole scabrous. 



Coxal scopa rather large, flat ?>. iiiaiiriis. 



Coxal scopa small, tuberculiform 7. ciiK'f i<*oi'iiis. 



Postpetiole finely aciculated; coxal scopa small 4. goniiaiius. 



Postpetiole punctured; coxal scopa large, flat 5. viola. 



Wings hyaline. 



Scutellum white; abdomen blaclv tinged with blue 29. a$;iiitus. 



Scutellum white only at sides; abdomen steel-blue 23. CH^rillcUS. 



Apex of abdomen with one or more white spots. 

 Posterior trochanters black. 



Wings fuliginous 2G. SC'Clcstns. 



Wings hyaline 1>?. Ka^viiS. 



Posterior trochanters white 41. extreiiiatatis. 



Coxal scopa wanting. 



Apex of abdomen immaculate. 

 Wings fuliginous. 

 Scutellum black. 

 Head large subquadrate; posterior angles of metathorax rounded. 

 Pale orbital lines distinct in front above the antennse; gastrocoeli 



large 1. Ori>hoii««. 



Pale orbital lines wanting; gastrocoeli small 2. Ka>it*iiis. 



Head of usual size; posterior angles of metathorax spiniforin. 



Abdomen deep black; gastrocoeli small, shallow 6. iiialacii!^. 



Abdomen tinged with blue; gastrocoeli small, deep...i;>. Kolitll!^. 

 Scutellum more or less white. 



Head large, buccate 1. OrplnMis, var. 



Head of usual size, not buccate 27. caligiiio.siis. 



Wings hyaline. 

 Scutellum black. 



Abdomen steel-blue 22. clialybciis. 



Abdomen black, sometimes faintly tinged with blue. 



Postpetiole aciculated I'J. a(or. 



Postpetiole punctured 20. apcrtus. 



Scutellum more or less white. 

 Postpetiole broadly dilated. 

 Gastrocoeli small, moderately deep; anterior orbits indistinctly 



pale 34. subcyaiiciis. 



Gastrocoeli very large and deep; pale orbital lines entire and 



distinct 3G. vitalifei. 



Postpetiole narrower, gradually dilated. 



Head large, buccate; postpetiole punctured 20. aportlis, var. 



Head of usual size; postpetiole finely aciculated.. ..37. Ilioiidax. 

 Apex of abdomen with one or more pale spots; scutellum white. 

 Three apical segments each with a pale spot; pale orbital lines distinct 

 in front above the auteuuse 39. truciilcnius. 



