1865.] 



119 



two larije semicircular spots, that on the secoad segment large and tri- 

 ano-nlar, on the remainin"- se"ments this stain becomes narrower, and 

 slightly blackish at extreme base ; the sutures also blackish ; apical 

 segment ferruginous, black at base and apex; venter fulvo-ferruginous, 

 with a black band at the base of the third, fourth and fifth segments. 

 Length 7 lines; expanse of wings 121 lines. 



Hah. — Rocky Mountains, Colorado Territory. (Ridings.) Coll. 

 Ent. 8oc. Philad. 



One 9 specimen ; % unknown. This beaiitiful species is at once 

 recognized by the large and singular projection of the clypeus, as well 

 as by the handsome ornamentation. Answers somewhat to the de- 

 scription of C. biffenfata Say, but not enough to warrant their iden- 

 tity certain. 



(i. Cerceris sexta, Say. 



Cerceris sexta, Say, Bost. Journ. Nat. Hist, i, p. 382. 



Black; face, two spots on collar, tegulse. postscutellum, spot on each side of 

 metathorax, and broad bands on abdomen, yellow; legs yellow and fulvous; 

 wings subbyaline. 



Ma/i'. — Black, closely punctured, clothed with a thin pale yellowish 

 pubescence ; face entirely, mandibles except tips, a dot behind the 

 eyes near their summit, sometimes wanting, and the scape in front, 

 yellow, sometimes whitish ; basal half of antennae bright ferruginous, 

 the remainder black. Thorax : two large transverse spots on pro- 

 thorax, tegulae, postscutellum, and an ovate spot on each side of the 

 metathorax, sometimes reduced to a dot, yellow; sometimes the scu- 

 tellum is faintly tinged with brownish ; the triangular basal space of 

 the metathorax shining, with slightly oblique strife on the sides and a 

 well-impressed longitudinal one in the middle. Wings tinged, more 

 or less, with fuscous, the tip and apical margins darker, covering the 

 marginal cell ; nervures pale ferruginous, the stigma yellowish. Legs 

 bright yellow, the four anterior femora behind, except tips, the apical 

 half of the posterior femora, their tibiae and tarsi within and above, 

 fulvous ; base of the four anterior femora beneath and the posterior 

 pair within, black. Abdomen more elongate and rather narrower than 

 usual, with the segments strongly contracted at base; the basal seg- 

 ment subglobose, either black or ferruginous, Avith a large or small 

 yellow spot on each side; the five following segments with a more or 

 less broad, continuous subapical, bright yellow band, slightly narrowed 

 on the middle anteriorly, where the bands are sometimes obsoletely 

 margined with obscure ferruginous; beneath sometimes stained with 

 ferruginous, the second to fifth segments each with a more or less de- 



