276 HYMENOPTERA OF AMERICA. [PART I. 



its rather bidentate metathorax ; by its clypeus 9 flattened, not 

 so convex, % shorter, not more prolonged below than above. 



In the Mexican variety, the form is much as in 0. Cordovse, 

 but it is larger; the clypeus 9 a little produced at its apical cud; 

 head and thorax very coarsely shagreened ; the second segment 

 of the abdomen shorter, its margin having its coarsely punctured 

 band impressed and widened in the middle. — This var. differs 

 from O.'formosus by its larger size, its clypeus more prolonged 

 at tip, metathorax not bidentate, and darker wings; from <). 

 Hidalgi and Iturbidi by its smaller size and metathorax not 

 acutely margined superiorly. 



Hab. The prairies from Missouri to Texas and New Mexico. 

 Mexican Cordillera (the variety) 5 ?, 2 V 



05. O. crypticus Say. — Rufus ; abdoniine flavo-trifasciato ; alis in- 

 fuscatis. 



Odyn. crypticas Say, West. Quarterly Reporter, II, 1, 1823, 80. — Say's 



Entora. (Le Conte), I, 1G8. 

 Jihygchium crypticum Say, Bost. Journ. I, 1837, 384, 3. — Say's Entoin. 



(Le Coxte), 7G5, 3.— Sauss. Et. Vespid. Ill, 184. 



Total length, 5 lines. 



Body rufous, much punctured; vertex and origin of the 

 antennae, black; antenna? dusky at tip; thorax with a black spot 

 before the middle ; scntel bilobate, with a longitudinal, deeply 

 impressed line ; metathorax concave ; wings dusky, paler at tip; 

 tergum with three yellow bands, the anterior one smallest and 

 subconcealed. 



Hab. Arkansas. 



This is most likely a pale variety of 0. annulatus. 



96. O. siilf incus SArss. (Fig. IS, 18a.)— 9 0. arvensi simillimns, at 

 metanato minna excavato ; niger, sulfureo-multipictus ; ore, clypeo et 

 facie snlfureis; oculis fiavo-, supra rufo-marginatis ; antennis fuscis, 

 scapo rnfo; pronoto flavo, angulis posticis mfis ; scutello flavo-bhnacu- 

 lato ; post-scutello, te^ulis macalis pleurarum et metanoti angulis, 

 sulfnreis, abdomine sulfareo, se^mentis 1°, 2° basi et in medio nigro- 

 signatis ; pedibus ferrugineo etsulfureo pictis ; alis ferrugineo-griseis. J . 



Odyn. suffureus Sauss. Revue de Zool. X, 1858, 170, 9 . 



Total length, 12 mm. ; wing, 9 mm. 



