AMERICAN HYMENOPTERA. 165 



with a narrower otie.the three foHowiug segments broadly black at base, apical 

 eepment fulvous; yellow at tip; gastrocoeli small and deep; postpetiole finely 

 aciculated. Length .60 inch. 

 Hah. — Kansas. 



96. comptus, Say, Bost. Jour, Nat. Hist, i, p. 229, % . 



Hub. — Pa., l)el., Md., Tex. A slender, gracefully formed species, 

 the abdomen being strongly narrowed to base. The prevaiiinj; color 

 is yellow with the vertex, occiput and aatennse except scape beneath, 

 black ; niesothorax black, with two central yellow lines, a yellow dot 

 on each side behind the tegalfe ; prothoras black, broadly margined 

 with yellow, pleura black, with a large yellow blotch on each side; 

 tegulse. scutellums and metatborax, yellow, the latter with a broad 

 central black stripe, sometimes interrupted at base; wings pale-yel- 

 lowish hyaline; legs yellow, posterior coxae black beneath, their femora 

 and tips of their tibiae tinged with ferruginous, sometimes the posterior 

 femora are blackish; abdomen very slender at base, gradually widen- 

 ing t^>wards the apex ; basal two-thirds of the first segment above, the 

 basal one-half or one-third of the second, third and fourth segments, 

 and the remaining segments except their apical margins, black ; some- 

 times the basal black band on the third segment is ij[uite narrow, while 

 all the others are broad. Length % .50 — .55 inch. 



This may be the % of atrifrons. 



97. atrifrons. Cress. Proc. Ent. Soc. Phil, iii, p. 157, 9 ; Trans. Am. 



Kn(. Hoc. i. p. 298. 

 Hah, — Pa.. 111. This species has much the same graceful form as 

 compiits. of which it may be the 9 , the abdomen being narrowed and 

 very slender at bsuse ; the face is entirely black, the anteuuaj slender, 

 with a white aonulus on flagellum ; anterior orbits, two slender stripes 

 on loesothorax, scutellum, two large spots on metatborax, coxae, and 

 band at tip of all the abdominal segments, yellow; legs fulvo-ferrugi- 

 Dous; wings yellowish-hyaline. Length 9 .50 inch. 



98. inconstans. Cress. Proc. Ent Soc, Phil, iii, p. 153, S . 



Hith. — C«Worado. An elongate rather narrow black species with 

 the face, clypeus, scutellum, most of legs, and the second, third and 

 fourth abdominal segmetiLs, yellow; the second and third segments 

 more or less varied with fulvous at tip, and the yellow on fourth seg- 

 ment contracted and interrupted medially; the two apical segments 

 are fulvous; wings yellowish-hyaline; po.sterior cox?e. their femora, 

 and tips of their tibiae black. J^ength % .55 inch. 



