156 HYMENOPTERA OF AMERICA. [PART T. 



low livery of its abdomen. It closely recalls the 0. bifasciatus 

 Fabr , although its head is narrower and its«clypeus more emar- 

 giuate. It also closely approaches the 0. debilitatus Sauss., 

 which has nearly the same form of head, but which is less slender 

 and has the thorax especially, much more strongly spinose. 



/A//-. United States. Connecticut. Wisconsin. Illinois. 



I owe this interesting species to the kindness of Mr. Edward 

 Norton and Mr. B. D. Walsh. 



5. S. jKlKllilais Sauss. — Gracilis, incur, nitidus, tenuiter punctatus ; 

 pronoto biaugulato; post-scutello et metanoto rugosis ; illo postice ex- 

 cavate, antice paulum altiore et utrinque in lateribus carinula longi- 

 tudinal i marginato; hoc profunda excavato, foyeola elevato-tnarginata 

 iustrncto : mesonoto valde sulcato; scutello sulco valde partito; abdomi- 

 uis primo segmento elongato, sutura valde promiuula instructo, superne 

 yugosissiune punctato et sulco obsoleto diviso ; segmentis reliqais niti- 

 dissimis; puncto frontali et post-oculari, maculis 2 pronoti, 2 scutelli, 

 pun. 'tn subalarij limboque segmentorum abdominis omnium, flavis ; 

 (segmentorum 3-5 fascia undulata submarginali); pedibus iiigris, tibiis 

 tarsisque flavis; alis byalinis, venis ferrugineis. % . Clypeo rotundato, 

 bidentato; mandibulis et scapo antice fascia fiava. Longit, 9 mm. 



Odijn. pumilus Sauss. Vespides, III, 1854, 197, 93. 

 Hub. Peru. (The author's collection.) 



6. §. cristatlis Sauss. — Sat parvus, niger, 0. murario formic similis; 

 inetanoto rugoso ; abdominis primo segmento sat grosse punctate, sutura 

 elevata, secundo latiore, basi punctato; puncto frontali, maculis 2 pro- 

 noti, fascia interrupta scutelli, macula subalari, liavis vel runs; ab'lo- 

 niinis segmentis 1,2,4 sulfureo lirabatis ; tibiis tarsisque ferrugineo- 

 variis; alis byalinis, venis fuscis, radio ferrugineo. £>. Long. 9 mm. 



Odytn rus cristatus Sauss. Vespides, III, 196, t)2, £> • 



IIuli. North America. 



This species appears to me to be very nearly, if not wholly 

 identical with 0. Philadelphiae. 



*V. S. Canadensis Sacss.— Parvulus, niger, gracilis, rugosus ; puncto 

 frontali, maculis 2 pronoti, 2 scutelli, macula subalari, abdominisqne 

 limbo segmentorum 1', 2', 4', flavis; tegulis fuscis; capite inflate, 

 an tennis infere insertis ; abdominis secundo segmento angusto, vix 

 latiore quam primum; alis hyalinis, apice fuscescentibus. $>. Longit, 

 8 mm. 

 Odijncrus canadensis Sauss. Vespides, III, 19'J, 91, £ . 



Hab. Canada. 



