342 IIYMENOPTERA OF AMERICA. [PART I. 



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

 ten perate regions of Cuernavaca, of the Iluasteca, and in the 

 valley of Mextitlan. 



Observation. — I have joined O. sobrinus with O. Huastecus, 

 because new specimens seem to establish the transition between 

 the two presumed species. Nevertheless, 0. sobrinus has a some- 

 what different metathorax. It is extremely difficult to decide 

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



139. ©. Otomitus Saoss. (Fig. 21.) — 0. Huasfeco similis, paulo minor, 

 argenteo- vet 1'ulvo-velutinus ; pionoto bidentato; metaioto maximerugoso, 

 valde foveolato ; pronoti margine .postico et angiitis, fascia post-scutelli, 

 tegulis, abdominis segmeutorum tirnbo, ouhraceis ; macula subalari 

 nulla; metanoto irnmaculato ; tibiis fulvo-niaculatis ; alis fttiTugineis, 

 apice griseis. — £. Clypeo truncato, nigro, in summo macula fulva. — 

 % . Clypeo bidentato, albido vel uiveo; anteunis subtus pallide fulvis. 

 Odyn. otomitus Sauss. Revne. de Zool., IX, 1857, 278. 



Total length, 9 > ^ mm - 5 wm g> % > 7 mm. 



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

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

 characters. 



?. 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' 

 clypeus, 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 

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

 post-scutel fulvous or dull yellow. Tegulse ferruginous No spot 

 under the wing nor on the metathorax. 



