236 AMERICAN HYMENOPTERA. 



Apical segments of abdomen mostly yellow ; abdomen strongly clavate. 



bureotJK n. sp. 

 Apical segments of abdomen narrowly jnargined with yellow, or entirely 

 without yellow margins. 

 Face entirely yellow ; third discoidal cell broad, the vein above usually 



broken and with a distinct stump crla.vatu!>i Cress. 



Face mostly black above clypeus ; third discoidal cell scarcely broad- 

 ened, vein not broken ; postero-median area of metathorax with 



median carina usually COiitrsftCta. n. sp. 



Scutellums entirely yellow. 



Posterior coxse entirely yellow, or in part black. 



Humeral cross-vein of hind wing broken in or below the middle; hind 

 femora and abdomen dusky; metapleura punctured. 



articiilaris n. sp. 

 Humeral cross-vein of hind wing broken much above the middle ; femora 

 rufous: abdomen rufous, black at base: metapleura perpendicu- 

 larly rugose hiiiiieraliK n. sp. 



Posterior coxge rufous; abdomen black at base, sometimes dusky at apex ; 

 posterior femora and tibiae entirely rufous or dusky at base and 

 apex. 

 Head black, or black and yellow behiud eyes; thorax usually black. 



al»4loiniiialis Cress. 

 Head rufous behind eyes; thorax more or less rufous- ■I'lifiniis n. var. 

 Thorax, abdomen and head rufous, or with yellow markings. 



Petiole of abdomen carinate, wings hyaline variatiis Prov. 



Petiole oval, polished and without cariuse. 



Wings smoky, body mostly rufous veiiusl ns Cress. 



Wings hyaline ; body mostly pale yellow polittis n. sp. 



Exyston iiigreo n. sp. 



'^ . — 7 mm. Black, pilose, with the following parts lemon-yellow : face, orbital 

 lines each side of antennae, mouth-parts, tegulte, scutellums, narrow apical mar- 

 gins on abdominal segments, four anterior coxae, all the trochanters, apex of 

 femora, front part of four anterior femora, four anterior tibiae, small annulus at 

 base and broad annulus in middle of hind tibitie ; tarsi more or less dusky, poste- 

 rior pair almost black ; antennae reddish J) rown, scape black ; wings fusco-hyaline ; 

 veins and stigma dark brown: cubito-discoidal vein broken, humeral cross-vein 

 of hind wing broken in the middle; scutellum rounded; periole of abdomen 

 broad, strongly carinate, spiracles not prominent. 



Two specimens from Colorado aud Seattle, Wash., Prof. 0. B. 

 Johnson (type, coll. G. C. D. and Amer. Ent. Soc. ). 



Exyston marginatum Prov., Add. Faune Hym., 99. 



p . — 7 mm. Black, with face, tegulae, scutellums, spot on scape beneath, broad 

 apical margin of abdominal segments, legs, except base and apex of posterior 

 tibiffi and femora, which are black; femora slightly reddish; wings hyaline, 

 nervures brown. 



Provancher's type of this species not seen. The description given 

 here is condensed from his own. The type is from Toronto, Canada, 

 bnt is not in the Quebec Museum. 



