238 HYMENOPTERA OF AMERICA. [?ABT I. 



6. Superior echjes of metathorax sharp. 



71. O. iJracli? gaster Sauss. — Niger, valde punctatus, omnino fulvo- 

 velutinus ; metathoracis excavatione lata, lsevi, argenteo-sericea, utrin- 

 que obtusangulata, snperne canthis arcuatis acutis marginata ; his a post- 

 scutello per Sssuram utrinque sejuuetis ; abdomine ovato, basi truncato ; 



capite omnino nigro; pronoti marginibus obsolete, tegulis parti in, post- 

 scutello, puncto sabalari et punctis 2 in angulis scutelli, metathoracis 

 canthis superioribus abdomiuisque segmentorurn l'-5' limbo, fulvis ; 

 primi fascia angusta, 2' lata; 2' margine late crasse punctato ; pedibus 

 nigris, artibns, tarsis et mandibularum apice obscuro-rufescentibus ; 

 tibiis anticis fulvo-variis ; alis subhyalinis, basi et costa subferrugineis 

 apice griseis. — 9* Clypeo bidentato, dentibus inter se distantibns, 

 riilis.— % ?. 



Odyn. brachygaster Sauss. Et. Vespid. I, 173, G3, pi. xvii, fig. 8 (1852). 

 —Rev. Zool. V, 1858, 167, 5. 



VarJ Margins of the abdominal segments narrow; antennae 

 ferruginous beneath ; wings hyaline, with fuscous veins. 



Very similar to 0. nasidens ; but also very distinct, the abdo- 

 men not being a.s conical and the 2d segment more elongate; the 

 antennae are also inure slender. 



Hab. Brazil. (Paris Museum and coll. of author.) ■ 



This can be well distinguished from Chartergus chartarius 

 (social wasp) by its truncate or bidentate clypeus (not angulate), 

 its long mandibles, its wider first abdominal segment, etc. 



Tl'i. ©. GuadiiJpeiisis Sauss. — Niger, valde punctatus; capite et 

 thorace rugosis, abdominis segmenti 2' margine et sequentibus valde 

 punctatis; linea mandibularam et scapi, macula frontali,pronoto omnino 

 superne, tegulis, macula subalari, macnlis 2 scutelli, post-scutello 

 metauoto utrinque, tlavis; ab lominis segmentis lo, 2° flavo-margin itis, 

 primi fascia utrinque aucta; segmentis 3-5 superne fulvo, subtus flavo, 

 tenuiter limbatis ; tibiis et tarsis Mavis ; alis flavescentibus apice infu- 

 matis — 9. Clvpeo flavo, nigro-maculato.— £ . Clypeo truncato, poly- 

 gonali, flavo. 



Variat. I'ronoti angulis posticis nigris. 



0. cuben'si aflfinissimus ; ab illo distincte differt: statu ra paulo minore ; 

 mandibulis nigris, flavo-notatis ; pronoto frequenter omnino flavo; 

 antennarum scapo nigro, linea (lava ornato; coxis et femoribus nigris ; 

 abdominis primo segmento /kiwJ acute truncato 1 ; segmentia 8-6 nigris 

 tenuiter flavo-margin at is. 



Odyn. Guadulpensis Sauss. Et. Wspides, I, ls2, 76 (1852). 



1 In our % specimen the first segment offers a sort of suture, but this, 

 I think, may be a mere accident of puncturation. 



