ODYNERUS. 203 



9. Clypcus yellow, coarsely punctured, a little wider than 

 long, terminated by a little lamellar border; mandibles yellow or 

 red. 



%. Smaller. Head wide. Clypcus polygonal, more widely 

 truncate. Legs yellow. (Antennae ?.) 



Bess. a. cliff'. — This species varies without doubt infinitely in 

 its colors, passing probably in one place to brown or to black in 

 its deeper color,, or preserving its yellow ornaments more or less 

 reduced ; in another place changing from yellow, by the paling of 

 its deeper color, and the extension of its ornaments, as we have 

 shown above for the 0. annulatus. It will not do then to seek 

 its distinctive characters elsewhere than in its form. 



It is easily confounded with the 0. annulatus, which has almost 

 the same livery and the male of which also presents a great head. 

 It is distinguished from it by its greater and less dense punctures, 

 the thorax remaining smooth for this reason ; by the absence of 

 lateral dentiform angles on the metathorax ; by the punctures of 

 borders of segments 2-4, which are greater, and separated, and 

 of a brown color; the % also by its shorter clypeus, which is not 

 regularly octagonal, the inferior borders not being identical with 

 the superior, the inferior being a little more prolonged. 



The 0. pratensis differs from the 0. foraminatus by its meta- 

 thorax, having a smaller concavity, less surrounded by swellings, 

 with more rounded borders, more circumscribed, less extended, 

 as far as the borders of the posterior face ; and by the absence 

 of little teeth behind the post-scutel ; by . a shorter and wider 

 clypeus, etc. 



It differs from the 0. Guerreri by its more conical abdomen, 

 by its less densely cribrose, and not velvety body, etc. Other- 

 wise, its color is of a gay orange-red, "common to insects of the 

 western coast of North America, and not of the brownish-red 

 peculiar to the Mexican insects. 



Ilab'. Lower California and the prairies of New Mexico. 9 

 from Cape St. Lucas (Lower California, Gh Xantus) ; £ from 

 New Mexico. 



** Abdomen rnore wcrt«-eonical„ slightly contracted anteriorly. 



10 1 ?. O. fla.x'opiU'ilifls Sauss. — 0. foraminato simillimus, Bed meta« 

 thoracis dentibus superioribus nullis; olypeo latiore, flavo, aigro-margi- 



