228 AMERICAN HYMENOPTERA. 



CTEIVISCUS Curtis. 

 (British Entomology. 1823, p. 40.) 

 G. Exenterns Hartig, Wieg. Archiv. f. Naturig. Jahrg. 3, 1837. 



This separation from the other species of what was the old genus 

 liy the above name is a natural one. The individuals of the species 

 composing the genus as it now is are smaller, more delicate, highly 

 polished, rarely rugose, or even coarsely punctured. The petiole is 

 very narrow at the base and widens quite evenly, and in $ very 

 rapidly, to the much widened apex. 



Thorax black, or with yellow markings. 



Scutellums black : hind coxae usually black ; face above clypeus black in 9 ! 



abdomen nearly black in % olypeatllS Cress. 



Scutellums more or less yellow ; face yellow; abdomen mostly rufous. 



Posterior coxse rufous or piceous eonsors Cress. 



Posterior coxae lemon-yellow flavicoxse Cress. 



Thorax, abdomen and legs pale rufous orbitalis Cress. 



Cteniscus clypeatiis Cress., Trans. Am. Ent. Soc. ii, 113. 



9. — 6 mm. Head and thorax black, with clypeus, mandibles, palpi, tegulse 

 and spot in front pale yellow ; abdomen varies from entirely black, except narrow 

 reddish apical margins of segments, to black at base and apex and usually lateral 

 margins, wnth the central portion of the abdomen rufous; apex of segments 6-8 

 usually narrowly margined with yellow ; legs usually pale rnfous with yellowish 

 trochanters and anterior coxse, but in the darker specimens the four anterior 

 coxse and trochanters and hind legs become dusky with the posterior coxae black ; 

 wings fusco-hyaline, nervures and stigma bi-own, the latter being thick, and deep 

 from the margin to the origin of the marginal nervure; antennae dusky rufous; 

 face, metathorax and abdomen closely punctured; areas of metathorax distinct; 

 cariiife on basal segment of abdomen distinct to beyond the middle of the seg- 

 ment ; abdomen broad, narrowed at apex. 



% . — Differs by being longer, more slender; with cariuae extending to the apex 

 of first segment of abdomen and with face and abdomen polished. In color the 

 males average darker than the females; the abdomen is mostly black, the second 

 and third segments having rufous spots on apical median portion and the rufous 

 ]iortion may broaden, and elongate onto the fourth and fifth segments ; four an- 

 terior legs, posterior trochanters, face, mouth-parts and cheeks beneath pale yellow ; 

 posterior legs dusky with coxae, and femora darkest. 



Four females and six males from Mt. Hood, Oregon ; Colorado, 

 " Hudson Bay Territory" and Mt. Washington, New Hampshire 

 (Mrs. Sloss(m). Type, coll. Am. Ent. Soc. 



Ctenisciis coiisors Cress., Trans. Am. Ent. Soc. ii. 113. 



g_ — 6 mm. Head and thorax black; face, except median black line, mouth- 

 jiarts, cheeks beneath, more or less of a large orbital spot above eyes connected in 

 front by a narrow orbital line, more or less of scutellums, tegulae, s]iot in front, 

 more or less elongate on humeral suture, stripe above anterior coxae, four anterior 

 coxae and trochanters, lemon-yellow ; remainder of legs ferruginous, posterior 

 tibiae sometimes dusky at base and apex; abdomen rufous with first segment, 



