276 HTMENOPTEBA OP AMERICA. [PART I. 



its rather bidentate meta thorax ; 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. Cordovae, 

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

 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 0. formosus by its larger size, its clypeus more prolonged 

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

 Hidalgi and Iturbidi by its smaller size and metathorax not 

 acutely margined superiorly. 



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

 Mexican Cordillera (the variety) 5 9,2$. 



95. O. crypticus Sat. — Rufus ; abdomine flavo-trifasciato ; alia in- 

 fuscatis. 



Ocbjn. crypticus Say, West. Quarterly Reporter, II, 1, 1823, 80. — Say's 



Entora. (Le Coxte), I, 16S. 

 Rhygchium crypticum Say, Bost. Journ. I, 1837, 384, 3. — Say's Entom. 



(Le Coste), 765, 3.— Sauss. Et. Vespid. Ill, 184. 



Total length, 5 lines. 



Body rufous, much punctured; vertex and origin of the 

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

 before the middle ; scutel 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. sulfureus Sauss. (Fig. IS, 18a.)— 9 0. an-e»s/simillimus, at 

 metanato minus excavato ; niger, sulfnreo-multipictus ; ore, clypeo et 

 facie snlfnreis; oeulis flavo-. supra rufo-marginatis ; antennis fuscis, 

 scapo rnfo; pronoto flavo, angulis posticis rufis ; scutello flavo-bimacu- 

 lato ; ]'ost-*cutello, tegnlis macalis pleurarum et rnetanoti angulis, 

 sulfureis, abdomine sulfureo, segmentis 1°, 20 basi et in medio nigro- 

 signatis; pedibus ferrugineo et sulfureo pictis; alis ferrugineo-griseis. 9. 



Odyn. sulfureus Sauss. Revue de Zool. X, 1S58, 170, 9 . 

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



