112 HYMENOPTERA OF AMERICA. [PART I. 



carinate, and hence we have established separate divisions to 

 receive these types. 



Let us add that these insects have wholly the appearance of 

 the No?'tonia, and that one cannot distinguish them but by the 

 dissection of the mouth. If then we separate these two genera, 

 it is that they seem to us to form a deviation from the genus 

 Odynerus in two different ways; the Nortonia conducting to the 

 Eumenes, and the Montezumia forming rather a detached rami- 

 fication which seems more to direct toward the Pollutes or Zethus. 



In fine the Montezumia have nearly the same buccate organi- 

 zation as the Monobia, and are distinguished from these insects 

 by their slender forms ; by their abdomen pediculate or fusiform, 

 not distinctly sessile ; and by the form of the metathorax, which 

 is convex, divided by a groove, but not excavated as with the 

 Odynerus, or which always at least offers two salient enlargements 

 rather than a posterior excavated surface. 1 



The genus Montezumia is almost exclusively American, but 

 it does not extend into the cold latitudes of this continent. It 

 appears only in Mexico, and extends southward as far as the 

 borders of Patagonia. It has not yet been met with in the 

 United States. It also appears to be limited to the eastern face 

 of the Andes, at least it has not yet been found upon the western 

 side of* America. 



The habits of these insects remain to this day entirely unknown, 

 although the structure of their mouth does not leave any doubt 

 that they lead a solitary life. Now, however, we may throw 

 some light upon this question, thanks to the kindness of Mr. Gr. 

 Claraz, who has been willing to send us the nests of Montezumia 

 ferruginea described below. 



These structures very much resemble the nests of Pelopoeus. 

 They are of agglutinated masses of earth, in which one finds the 

 cells disposed in a parallel order, in which the insect imprisons 



1 It is true that certain Montezumia having the pediculate abdomen 

 offer a sort of concavity of this kind on the metathorax (M. Lepriurii, 

 Huasteca) but the types with the non-pediculate abdomen, which alone 

 could be confounded with the Monobia, have always the metathorax con- 

 vex, clubbed, and unarmed. Constantly here, as elsewhere, one finds 

 transitory types, but we have allowed that the genus Monobia is not 

 entirely decharacterized in the genus Montezumia (see the Monobia egregia 

 and especially the Monobia variabilis). 



