298 E. T. CRESSON. 



I. consignatus. — %. T?]ack, opaque; head narrowed beneath ; anterior orbits, 

 face, except a narrow black line down the middle, a spot on each side of the 

 clypeus, and a spot on the lower 'part of the cheeks, white; palpi pale: anten- 

 ux long, subserrato, slender at tips, black, with a white or yellowish-white an- 

 iiulus about the middle: tegulse, a sutural line before and a spot beneath, and 

 the scutellum, white; metathorax immaculate, central area moderate, quad- 

 rate ; wings hyaline, fai.ntly dusky ; legs black, tips of four anterior femora, the 

 anterior pair within, and their tibise and tarsi at base, whitish; posterior tibiae 

 palish at base ; abdomen long, narrow ; a wavy line on each side of second seg- 

 ment, a spot on each side of third, sometimes its posterior margin, and the pos- 

 terior margin of the remaining segments, whitish. Length 7 lines. 



Hab. — West Virginia, (Ridings). Two %, specimens. 



I. robustus. — 9. Large, robust, black; anterior orbits, dilated on each side 

 of the face, yellow; middle of face brownish; clypeus ferruginous, brownish at 

 tip; mandibles brownish; antennee rather long, stout at base, slender at tips, 

 reddish-brown at base, yellow in the middle and black at tips ; tegulse and a 

 line beneath, yellow; scutellum flat, polished, yellow; metathorax finely ru- 

 gose, with a large subrotund central area; wings yellowish-hyaline, nervures 

 and stigma ferruginous; coxae black, the two anterior pairs spotted beneath 

 with yellow; trochanters yellow; four anterior fem<:ira ferruginous, yellow at 

 tips, their tibiae and tarsi yellow; posterior femora and tips of their tibite black, 

 rest of their tibiae and their tarsi yellow; abdomen robust, convex, tip com- 

 pressed ; first segment broadly dilated at tip, black, second and third with the 

 anterior half yellow, the posterior half brown-ferruginous, remaining segments 

 black, with their posterior margin yellow. Length 7i lines. 



Hab. — Canada, (Billings.) One 9 specimen. Allied to jucundus, but very dis- 

 tinct. 



I. subdolus. — 9" Robust, ferruginous or brown-ferruginous, face and cheeks 

 stadned with black ; antennae stout, joints thick set, ferruginous, blackish at base 

 and tip, yellowish or whitish in the middle ; thorax on the sides and beneath 

 black; mesothorax shining; scutellum yellow, the region on each side black; 

 metathorax deeply excavated behind, central area large, subquadrate; wings 

 uniformly fusco-hyaline ; legs ferruginous, coxae, four anterior femora behind, 

 and the posterior pair, except base, black ; abdomen robust, ovate, ferruginous ; 

 second and third segments with a yellow band at tip, sometimes obsolete on the 

 third segment ; base of second, third and fourth segments more or less black, 

 generally the tip of first segment has a yellow spot on each side, sometimes con- 

 tivient; apical segment entirely ferruginous. Length 5^ — 6 lines. 



Hab. — Maine, Massachusetts. Four 9 specimens. 



I. creperus. — %. Dill'crs from Grote by the thorax being always black, not 

 varied with fulvous; by the posterior femora, except base, the tips of their ti- 

 biae, and the posterior coxas, being black; and by the second and following seg- 

 ments of the abdomen being fulvo- ferruginous, black at base, without any yel- 

 lowish shade at the tip of the segments, except tliat of the lirst, which is always 

 yellow. Length &h — Ih lines. 



Jlab. — Canada, West Virginia, Illinois. Sixteen %, sjiccimens. 



I. atrifrons is probably the 9 o{ compius. It varies in the width of the abdo- 

 minal tascite and also in the markings of the metathora.x. The lines on the 

 mesothorax are sometimes obsolete or wanting. 



