46 HYMENOPTERA OF AMERICA. [PART I. 



salient. Sciitellum punctured with coarse points, an**, divided by 

 a groove. Metathorax punctured on each side of its summit, 

 neither punctured nor striate on its posterior face, but velvety. 

 Enlargement of the petiole convex; its swelling, seen in profile, 

 is more salient near its base, and is depressed and contracted 

 behind; on its extremity is an excavation. This enlargement, 

 seemingly smooth and polished, is quite finely punctured. Second 

 segment very shining and polished, its pedicle equalling a third 

 of its length and widening posteriorly; the globular bell, as long 

 as wide, enlarging gradually. Seen in profile, it is much more 

 swelled above than beneath. 



Insect black, with orange marking?, which are in general 

 arranged as follows: sinus of the eyes, the transverse bar of the 

 frontal T, a point on the summit of each eye and the orbit behind 

 the eyes ; the prothorax, wholly or in part, a spot under the 

 wing, wing-scale, the anterior portion of the scutellum and of the 

 post-scutel, two spots on the metathorax and the extremity of 

 the petiole, orange. These markings are more or less developed; 

 they may be more extended, or in part wanting. The remainder 

 of the abdomen is of a beautiful red or ferruginous, with the 

 base of the pedicle black. Scape of the antennas ferruginous. 

 Feet yellow, varied with ferruginous. Wings ferruginous, with 

 the end lightly gray, carrying a little reflection of violet. 



?. Clypeus rounded, black, with two oblique yellow bands at 

 the superior margin; 2d joint of the antennas ferruginous; a 

 whole band of yellow under the wing; the margin of the 2d abd. 

 segment narrowly yellow. 



V End of the antennas rolled spirally. Clypeus orange, finely 

 punctured; its inferior border armed with two separated teeth, 

 with an arcuate border between them, in the middle of which is a 

 little salient tooth, often hardly visible. The first two and the 

 last two articles of the antennas orange; the flagellum annulate 

 with this cjlor beueuth ; the terminal spiral orange; the last 

 article obscure. 



Var. The specimens of other localities possess, without doubt, 

 more of black on the abdomen and antennas. 



Ress. a. diff. — This LHdymogastra is easily distinguished from 

 Z. Chicotencatl, by the rugose aspect of its head and thorax, by 

 its much less striate metathorax, by its petiole more swelled 



