G. C. DAVIS. 239 



Exystoii artieiilatiis n. sp. 



% . — 7-10 mm. Black, with face, mouth-parts, anterior part of cheeks, orbital 

 lines each side of antennse, scape beneath, tegulae, line beneath, scutellums, four 

 anterior legs, posterior coxse and trochanters and apical margins of terminal 

 segments of abdomen lemon-yellow; posterior femora black at base, reddish at 

 apex; tibise yellowish, with a black annnlus near base; tarsi dusky; abdomen 

 piceous, black at base and segments 3 and 4 and apex of 2 more or less rufous; 

 wings subhyaline, nervures and stigma brown, yellowish at base : cubito-discoidal 

 vein strongly curved, but not broken; humeral cross-vein of hind wing broken 

 in or below the middle; third median area transversely rugose; basal areas 

 shining and separated by high carinse ; lateral areas punctured ; abdomen shining, 

 carinte on petiole prominent; spiracles not raised. 



9, wiiich is in the coll. U. S. Nat. Mus., has the abdomen nearly all yellow on 

 apical portion and the abdomen and legs are more rufous. 



Three males from Montana and Brookings, S. Dak., Prof. Aldrich ; 

 female from Colorado, Prof. Gillette (types, coll. G. C. D. and Am. 

 Ent. Soc). 



Exyston liunieralis« n. sp. 



% . — 9 mm. Black, abdomen ferruginous beyond the middle of second seg- 

 ment : face, anterior orbital lines, scape beneath, mouth-parts except teeth, ante- 

 rior part of cheeks, tegulae. line beneath, scutellums, sutural line above anteiior 

 coxjE, four anterior legs, posterior coxfe and trochanters and apical margins of 

 abdominal segments .3-6. yellow; antennfe fulvous, dusky at base above; wings 

 hyaline, nervures and stigma brown ; cubito-discoidal vein broken and with 

 stump ; humeral cross-vein of hind wing broken much above the middle ; third 

 median area of metathorax and lateral areas adjoining, irregularly rugose ; meta- 

 pleura perpendicularly rugose; abdomen shining; carinse on petiole prominent; 

 spiracles slightly enlarged. 



One specimen from Canada (type, coll. Amer. Ent. Soc). 



Exyston abdoiiiiiiaIi><i Cress. (CTw/w»s), Proc. Ent. Soc. Phil, iv, 264. 



9 % • — 6-9 mm. Black ; face, scape beneath, mouth-parts lower portion of 

 cheeks, tegulae, scutellums, prosternum, sometimes entire prothorax and spots on 

 mesopleurap. four anterior coxae and all of trochanters, lemon-yellow; anterior 

 legs reddish yellow ; posterior coxae rufous, femora and tibite rufous or narrowly 

 black at base and apex, tarsi usually dusky ; extreme base of posterior tibiae 

 sometimes marked with yellow; abdomen black, at least on basal half of petiole, 

 usually mostly rufous, apex sometimes dusky and sometimes almost entirely 

 yellow in 9 ; antennae reddish brown, black at base above; wings hyaline, ner- 

 vures and stigma iirown : thorax polished, sparsely punctured, metapleura punc- 

 tured, apical median area of metathorax irregularly or transversely rugiilose. 



Six females and four males from C/olorado, Montana, Nevada, 

 Michigan, Illinois, New Hampshire and Massachu.setts (type, coll. 

 Amer. Ent. Soc). 



Var. riifiniis n. var. — Diffei-s from (thdominnlis hy having the head behind the 

 eyes rufous, in having a broad transverse band on metathorax, pi-othorax in front 

 of tegulae and more or less of mesopleune, rufous ; abdomen not black at ajiex. 



TKANS. AM. ENT. SOC. XXIV. SEPTEMBER. 1897. 



