360 HYMENOPTERA OF AMERICA. [PART I. 



ments of the abdomen, yellow. The 4th segment (often ?) with 

 an incomplete yellow band. Wing scale brown, margined with 

 yellow or ferruginous. Feet black; tibiae at base outside and 

 their apical spines, yellow. Wings smoky. — ?. Clypeus yellow, 

 widened below, terminated by two very strong, blunt, black 

 spines. Mandibles and antennae wholly black. A yellow line 

 between the insertion of the antennae. 



Bess. a. cliff. — This small species is quite distinct by its 

 strongly tuberculate metathorax. It could only be confounded 

 with 0. chichimecus, but it is not so small, nor as slender; the 

 thorax is not as cylindrical; the body not as strongly punctured; 

 the scutel is not crested ; the metathoracic tubercles are much 

 stronger and the direction of the sharp external ridge of these is 

 convergent downward, while in chichimecus the tubercles are on 

 the contrary a sort of superior margin of an indicated cavity of 

 the metathorax. 



Compare also 0. olmecus and nahuus. 



Hab. The temperate parts of Mexico. I caught only one 

 male in the valley of Mextitlan. 



Subgenus EPIPONUS 1 Shuck. 



Epipona Shuck. ; Sacss. — Oplopus Wesm. ; Sacjss. Vespid., I, 217. — 

 Oplomerus Westwood. — Pterochilus ex. p. Herr.-Sch.eff. 



Abdomen quite ovate, depressed ; the first segment cup-shaped, 

 sessile, or sub pedunculate at base, sensibly narrower than 

 the 2d, but not constricted at base. Thorax short, rather 

 globular. Metathorax rounded, destitide of angles and of 

 sharp edges, without rugosities. Second recurrent nerve 

 of the anterior wing falling upon the 2d transverso-cubilal 

 nerve or very close to it. — (Appearance of the genus 

 Pterochilus.) 



% % . Antennae having at times the last joint recurved like a hook ; 

 these organs being more often elongate, thick, with their 

 last joints comp)ressetl, flattened, curled up to a spiral. — 

 Clypeus generally wider than long ; very strongly bidentate. 



This type quite recalls the appearance of Pterochilus and it 

 forms the intermediate step between these insects and the true 

 Odynerus. The characters of the Division Epipona are princi- 

 pally to be found in the males, but the appearance of these insects 



1 W»7rovcc, laborious. 



