ODYNERUS. 25Y 



taken in saying that the post-scutel is slightly crenulate ; how- 

 ever, one finds under this description some variations according 

 to specimens. 



SJr. O. dorsalis 1 Fabr. — Validus, niger, valde punctatus ; clypeo 

 integro, metauoto postice striato, utrinque dente armato, marginibus 

 rugosis, obliterates, uullomodo acutis, canthis O nullis, % elevatius- 

 cnlis ; ore, clypeo, antenuarum articulis 1-3, inaculis post-ocularibus, 

 pionoto, scutello, tegulis, rufis ; prouoto medio, post.scutello et abdo- 

 minis primi segoienti margine, flavis ; margine secundi et tertii rugo- 

 sissime punctatis ; — % antennis basi, maculaque subalari rufa ; abdo- 

 minis segmentorum margine 20, 3° flavo, secundo reflexo, subcanali- 

 ciilato; pedibus flavis, basi nigris; alis fuseo-cyaneis. 



Variat a fusco et ferrugineo-variegato ad omnino ferrugineuin ; primo 

 segmento flavo-uiargiuato. 



Vespa dorsalis Fabr. Syst. Ent. 3(57, 25 (1775). Ent. Syst. 265, 44.— 



Oliv. Encycl. Meth. VI, 685, 81. 

 Polistes dorsalis Fabr. Syst. Piez., 273, 19. 

 Rhynchium balteatum Say, Bost. Journ. I, 1837, 383, 1. — Say's Eutom. Le 



Conte, II, 764, 1. 

 Monobia sylvatica Sauss. Et. Vespid. Ill, 168. 2 



Rhynchium Louisianum Sauss. Et. Vespid. 1, 106, 7 ; pi. xiii, fig. 9 3 (1852). 

 Rhynchium dorsale Sauss. Et. Vespid. Ill, 171. 



2 . Total length, 17 mm. ; wing, 14 mm. 

 % . Total length, 17 mm. ; wing, 12 mm. 



2 . Large. Clypeus wider than long, but pyriform, terminated 

 by a truncation or even a little rounded; its surface covered with 

 quite fine punctures. Mandibles long, hooked; armed in the 

 middle of their inner border with 3 or 4 oblique teeth, but their 

 final portion simply cutting, not dentate. Head and thorax 

 densely cribrose with strong punctures ; prothorax retracted 

 before. Scntel briefly truncate, bearing a crenulate crest, inter- 

 rupted in the middle. Metathorax very coarsely punctured, very 

 rugose upon its borders ; quite variable according to specimens; 

 its hinder plate quite flattened, striate, forming on each side a 

 dentiform angle (at times blunted) ; its superior borders some- 

 times quite trenchant, sometimes effaced, scarcely offering tren- 



1 Compare Rhynchium dorsale, page 143. 



2 Compare page 132, No. 3, most likely a different species. 



3 On the inscription upon this plate, in place of: 9. Rh. limbatum, read : 

 10. Rh. limbatum; and in place of: 10. Rh. Louisanum, read: 9. Rh. Louisi- 

 anum. 



17 



