342 HYMENOPTERA OF AMERICA. [PART I. 



a % in the valley of Mexico ; and several other specimens in the 

 temperate regions of Cuernavaca, of the Huasteca, and in the 

 valley of Mextitlan. 



Observation. — I have joined 0. sobri?ius with 0. Huattecus, 

 because new specimens seem to establish the transition between 

 the two presumed species. Nevertheless, O. sobrinus has a some- 

 what different metathorax. It is extremely difficult to decide 

 upon the species of these small Odyneri, all quite variable. 



139. O. Ofomitus Sauss. (Fig.2I.)— O. Huasteco s : ,mi\is,p*u\o minor, 



argenteo- vel fulvo-velntinns ; pronotobidentato; metai.Aoitiarimentyoso, 

 valde i'oveolato ; pronoti margine postieo et angnlis, fascia post-scatelli, 

 tegulis, abdominis segmentorum limbo, oclnaceis ; macula subalari 

 nulla; metarioto immaculato ; tibiis fill vo-maculatis ; alis ferrugitieis, 

 apice griseis. — 9- Clypeo truncate, nigro, in summo macula fulva. — 

 % . Clypeo bidentato. albido vel niveo; an tennis subtus pallide fulvis. 

 Odyn. oiomitus Sauss. Revue de Zool., IX, 1857, 278. 



Total length, $> > 9 mai. ; wing, £ , 7 mm. 



Very similar to 0. Huastecus ; having the same appearance, 

 and the same kind of livery; differing principally in the following 

 characters. 



9. Size rather smaller. Clypeus less elongate, truncate at 

 tip. The impression of the vertex more distinct. Angles of 

 prothorax quite dentiform. Metathorax truncate; its hinder 

 face occupied by a large and deep concavity, punctured and 

 rugose, but not margined by sharp edges ; the upper face of the 

 metathorax and the edges of the excavation extremely rough, 

 occupied by very large punctures, or rather by little reticulate 

 dimples, which occupy the superior margin of the excavation. 

 First abd. segment punctured, much like the head ; the second 

 densely punctured, and having on its posterior margin a little 

 stronger zone of punctures, but this margin not canaliculate, 

 nor reflexed ; the 3d still rather strongly punctured ; those fol- 

 lowing densely but not strongly punctured. The whole insect 

 rather velutinous, clothed with grayish or fulvous pile. Meta- 

 thorax argenteous. A spot or a band on the summit of the 

 clypens, a frontal spot, a line on the scape, a very little spot in 

 the sinus of the eyes, and a spot or line behind their summit, dull 

 yellow. Posterior margin of prothorax, its angles, and a line on 

 post-sentel fulvous or dull yellow. Tegula? ferruginous No spot 

 under the wing nor on the metathorax. 



