324 HYMENOPTERA OF AMERICA. [PART I. 



Still I find a difference. 1st, in the form of the head, not so 

 circular, a little broader, giving it another appearance; 2d, in the 

 1st abd. segment, evidently smaller, not so broad at its base, 

 but a little more funnel-shaped, a little depressed, a little longer, 

 not quite as sessile. This becomes very evident when the abdo- 

 men is bent downwards. 1 It is also not quite as wide as the 2d 

 segment ; this being longer than in covformis and a little con- 

 stricted at base, to fit into the 1st segment. 



These characters of the abdomen seem to me to indicate a 

 species different from 0. conformis, but which can only be dis- 

 tinguished by a very experienced eye. — I can only compare -the 

 females, the male of 0. conformis being unknowm to me. Com- 

 pare 0. Pennsylvanicus. 



Ilab. The United States. New York, 2 ?, 3 %, taken by me. 

 Connecticut, 9 9, G % (E. Norton). 



124. ©. Xantliiamss Sauss. 9.— Niger, clypeo punctato, thorace 

 laevi, impunctato; uietanoto solo rugoso; post-scutello trans verse obtuse 

 cristato ; metathoracis foveola superne subacute marginata ; abdomine 

 punctato; secundi segmeuti linea marginali crasse punctata ; tertio iu 

 medio perrugose punctato; reliquis tenuiter punctatis ; scapo antice, 

 puncto mandibularum, frontali, oculari et post-oculari, fasciaque arcuata 

 iu summo clypeo, maculis 2 obliquis pronoti, macula subalari, post- 

 scutello, fasciis 2 metanoti, abdominis vittis 2, maculisque 2 parvulis 

 lateralibua segmentorum 1>, 2', flavis ; pedibus runs, luteo-maculatis, 

 basi nigris ; tegulis rufis, flavo-maculatis. 



Odyn. Xantianus Sauss. Revue de Zool. XXII, 1870, 103, 22, 9. 



Total length, 11 mm. ; wing, 7.5 mm. 



9. Size, form, livery nearly as in 0. anormis, but differing 

 from it by the following characters. Clypeus a little more 

 coarsely punctured and more truncate. Thorax smooth, not 

 sensibly punctured, except on the upper face of metathorax. 

 Scut el parted by a groove. Post-scutel elevated into a sort of 

 blunt crest, flattened behind (seen from behind the edge is arcuate 

 or rather trapezoidal, nearly bi-mamillated). Metathorax having 

 its superior face a little prolonged behind the post-scutel, includ- 

 ing it on both sides; widely truncate ; its hinder face or excava- 



1 This position is a quite indispensable condftion for the good study of 

 Odpierus, and should be given to all the specimens. 



