EUMENES. 93 



is sometimes not margined, sometimes margined by a little 

 cordon; this is not preceded by a regular channel as in Division 

 Omicron, but rather by three impressions, which makes the salient 

 margin appear somewhat bidentate before; the impression of the 

 middle is always the most distinct. 



A. Large species, with black icings. The pear of the abdomen 

 rather depressed; that is, not compressed. 



a. Body smooth, shining, not punctured. {Thorax elongate, petiole strongly 

 campanula!- ; its sice/ led part convex, not parted by a groove, its margin 

 preceded by a channel as in Division Omicron. 



33. E. Aztecus Saups. — Validus, ater, nitidns, haud pnnctatus ; pro- 

 noti margine postico medio, post-scutello, petioli margine, et abd. secundi 

 seginenti limbi fascia iuterrupta, pallide ocbraceis ; antennis et tarsis 

 anticis subtus ferrugineis ; alis liigro-coeruleis. J • 



Total lengtli, 22 mm. ; wing, 17 mm. 

 Eumenes Aztecus Sauss. Revue et Mag. de Zool., IX, 1857, 272. 



?. Large, black, smooth, and polished, without punctures: the 

 body throughout smooth, shining, and satin-like, nearly glabrous, 

 with neither punctures nor distinct strias, even on the metathorax 

 or the petiole. Clypeus bidentate at the extremity, smooth and 

 polished like the remainder of the body. Its emargination angu- 

 lar. Thorax long; disk of mesothorax lengthened. Pyriform 

 part of petiole wide, strongly campanulate; little swelled, convex 

 above ; its posterior border formed by a salient cordon preceded 

 by a channel. Second abdominal segment depressed ; but the 

 end of the abdomen a little compressed (without this last cha- 

 racter this insect would have the appearance of a Pachymenes). 



Antenna? long and slender, black, ferruginous beneath. Feet 

 black ; tibias and anterior tarsi with golden hairs, appearing yel- 

 low. A little arcuate line in the middle of the posterior border 

 of the prothorax, two dots on the scutellum, post-scutel, and a 

 narrow edging on the margin of petiole, pale tawny; second seg- 

 ment generally marked with a pale-tawny submarginal border, 

 narrow and widely interrupted in the middle. Wings black, varied 

 with very deep-violet reflections. 



Var. Only the post-scutel and the petiole marked with pale 

 tawny. 



