96 HYMENOPTERA OF AMERICA. [PART I. 



9. Clypeus convex, punctured, the tip flattened, notched, and 

 bidentate; the teeth lamellar. Head short, not dilated behind the 

 eyes, cribrose with punctures, as also the thorax, which is large, 

 short, globular; the metathorax convex and more densely punc- 

 tured; the scutels convex, much inclined, continuing the convex 

 surface of the metathorax. Petiole at first linear, then pyriform, 

 lengthened, and truncate, covered with punctures, insensibly bi- 

 dentate in the middle and bordered posteriorly by a hardly salient 

 cordon, before which are three depressions, of which the middle 

 one often forms a large hollow. Second segment compressed, flat 

 beneath, very convex above, covered with punctures, but yet 

 smooth and shining; toward the middle of the posterior border 

 of the second segment they are so gathered together as to form 

 a depression (which, however, is often wanting) ; its posterior 

 border with double leaves; the upper leaf thick, a little sinuous, 

 slightly concave in the middle; the second border not being bent 

 upward. All the body covered with a short, gray pile, not cha- 

 toyant. 



Insect of a shining black; two oblique spots at the summit of 

 the clypeus, the carina between the antennas and two dots behind 

 the eyes, border of the prothorax, post-scutel, often a spot under 

 the wing, often two spots at the summit of the metathorax and at 

 times two dots on the middle of the same, two variable dots on the 

 sides of the second segment and along the margin of the same a 

 scalloped border, sulphur yellow ; legs black, tibia? varied with 

 yellow : wings brownish with violet reflections. "Wing scales black, 

 bordered with brown or spots of yellow or red. % clypeus biden- 

 tate, entirely yellow or with a black dot. covered with a silvery 

 pile ; scape of the antennas marked with a yellow line and the 

 hook of the same ferruginous. 



Var. 9 %. The second abdominal segment more or less com- 

 pressed, the third and fourth segments often wholly or in part 

 bordered with yellow. Wing scales shining, often black, or 

 marked with a yellow dot. A yellow dot under the wing. The 

 yellow dot behind the eye often wanting. 



This is a very distinct species from its large size, its strong 

 puncturing in the form of pin holes, from its slender form and 

 its violet wings: from its shining black color, generally but little 

 changed by the very short hair of the insect. 



