212 AMERICAN HYMENOPTERA. 



tures; abdomen shining, subclavate, somewhat depressed at base; second seprment 

 and basal two-thirds of third segment coarsely punctured ; apex of third and 

 basal two-thirds of following segments finely punctured ; apex of segments pol- 

 ished, scarcely punctured; median carina reaches the apex of third segment, 

 lateral carinse reach only as far as the segment, is coarsely punctured. 



One specimen from Illinois and the type from Kansas (type, coll. 

 Ash mead). 



TRI€L,ISTUS Foerst. 

 (Synopsis der Fam. und Gatt. der Ichneumonen, 1868.) 



Head transverse ; face convex, protuberant, clypeus not separated, 

 eyes emarginate. Thorax robust, somewhat depressed above, meta- 

 notum polished, not completely areolated. Abdomen broadly sessile, 

 polished, genitatia hidden, or only slightly exserted ; areolet of wings 

 so variable in wings of individuals of some species that Amesolytus 

 cannot be separated from it by this character alone ; legs short, 

 strong, femora incrassate. 



To this genus belongs Cresson's Exochus varipes (locality?) and 

 E. pulchripes of Mexico. 



The following characters may be used to separate our species : 



Thorax black. 



Face and abdomen entirely black. 

 CoxiB black, at least posterior pair. 



Legs brown, nearly black briiiinipes Cress. 



liCgs ferruginous <'Oiigeiier Holmg. 



Coxfe and legs ferruginous ; size large, areolet small curvator Fab. 



Coxge and legs fulvo-ferruginous ; size small, areolet large- pygmseiis Cress. 

 Face yellow to dusky red, venter and two apical segments of abdomen rufous. 



apicalis Cress. 

 Thorax and abdomen rufous, or nearly so. 



Posterior tibise with white annulus; face white ferrugineus Ashm. 



Posterior tibiae not annulate with white. 



Face piceous; thorax without white markings tlioracieiis Ashm. 



Face white ; thorax with white markings atriceps Walsh. 



Triclistus briiuiiipes Cress. {Exochm), Proc. Acad. Nat. ScPhil. 1878. 374. 

 9. — 5mm. Black, legs dark brown to piceous, coxse black; mandibles and 

 palpi rufous ; tegulie black ; anteunte brown, scape black ; abdomen shining, im- 

 punctured, basal segment without central groove or carina; wings rufo-hyaline, 

 veins and stigma reddish brown, paler at base. 



Two specimens from Nevada. Type, coll. Amer. Ent. Soc. 



Trielistus congener Holmgren (Exochus), Mon. Tryphon, Suec. 319. 



J '^ . — 7-8 mm. Black; legs, except coxge, ferruginous; tegulte and palpi pale; 

 abdomen smooth, shining, with only a few shallow, scattering punctures, more 

 common in % ; carinse on basal segment extending nearly to middle of the seg- 

 ment in 9 ^'i*! more prominent and a little beyond in %; wings rufo-hyaline ; 

 veins and stigma reddish brown. 



