200 HYMENOPTERA OF AMERICA. [PART I. 



Insect black. Mandibles, summit of the clypeus, the first two 

 or three articles of the antenna?, a spot on the forehead, the inner 

 border of the orbits, or a spot in their sinus, a spot behind the 

 summit of the eye ; two spots on the prothorax, tegalae, a 

 under the wings, post-seutel, angles of the metathorax, first seg- 

 ment of the abdomen, and feet, red: bordering of the first two 

 segments of the abdomen, yellow. Wings brownish, with violet 

 reflections. 



Tar. a. Clypeus wholly red. 



b. Second segment entirely black ; only presenting an inter- 

 rupted border. 



c. The ridges which border the fossette of the metathorax 

 blunt, interrupted on the summit. The suture of the first seg- 

 ment effaced by the punctures. Punctures notably less coarse. 

 (In general, some small females with the 2d segment bordered 

 with yellow.) Wings only sinoky toward the end. 



% . Sculpture very coarse. Clypeus punctate, shortly biden- 

 tate, pale yellow or orange. Scape of the antennae often adorned 

 with an orange line ; the flagellum like that of the female, or 

 wholly black, or ferruginous beneath in its first moiety ; hook 

 black. Size as with the female. 



Tar. A. Post-scutel yellow. The ornaments of the head and 

 those of the anterior part of the corselet, orange or yellow. Their 

 size variable. 



B. Metathorax entirely red. 



C. No yellow band on the first segment ; its base black. 



D. The prothorax almost entirely red. 



E. Second segment adorned with two yellow dots. (The 0. 

 ammonia.) 



Bess. a. diff. — This species is distinct by the coarseness of the 

 punctures, by the strength of the ridges of the metathorax, and 

 by the red ornaments of the body. 



Hah. The Southern United States. Carolina. Florida, etc. 

 5 2, 4 % (E. Norton). 



Observation. — We have not before our eyes a specimen which 

 corresponds to our description of the 0. ammonia Sauss., in which 

 the 2d abdominal segment is ornamented with two yellow spots 

 and the suture of the first very indistinct or wanting. We think, 

 however, that this Odynerus is but a varietv of the 0. histrio. 





