142 HYMENOPTERA OF AMERICA. [PART I. 



yellow; border of segments 1-3 yellow, the following ferruginous; 

 the sides of the second segment chestnut-brown or ferruginous. 

 (Cordova.) The colors are very variable. 



c. (Highly-colored livery.) Forehead and vertex black, with a 

 yellow spot between the antennae. Thorax blackish or black, 

 with the prothorax, two lines on the mesothorax, two spots or a 

 band on the scutel, and the sides of metathorax, rufous ; post- 

 scutel yellow. The first abdominal segment blackish, with two 

 rufous spots, or a band, and the hind margin yellow ; the rest 

 of the abdomen brown-rufous, with yellow margins. Feet black 

 at base. Wings smoky, of a blackish-yellow with a golden 

 reflection. — % . Clypeus yellow, with a rufous shading. 



Bess. a. cliff. — The females are remarkable for the flatness of 

 the scutels and of metathorax ; for the separated punctures and 

 the body hirsute with tawny hair almost as among the hairy 

 insects. As regards color this exactly resembles the Odynerus 

 tuberculiceps, and approaches very much the Montezumia Brasili- 

 ensis and macrocephala in form and in the ferruginous color. 



Eab. The hot and the temperate regions of Mexico. I have 

 taken diverse specimens of this interesting insect in the valley of 

 Meztitlan (eastern Cordillera), at Morelia, and at Pazcuaro 

 (Michoacan). 



Gen. RHYXCHirJI Late. 



RygcJtiuyn Spixola, Lath., Sat, Lep., St. Fakg. 

 Rhynchium Sadss. 



This genus is so unnatural, that if one did not feel the necessity 

 of separating as many species as possible from the large genus 

 Odynerus, I should have abandoned it. 



Indeed the Rhynchium only differ from the Odynerus by their 

 large size, in the conical form of the abdomen, and in the length- 

 ening of the maxillary palpi, of which the second and third joints 

 are long and slender, while the last three taken together are not 

 longer than the third. But this latter character seems to accord 

 rather with the large size of the insect than with its peculiar 

 form Several Odyneri have a tendency to this, as for instance 

 the 0. luctuosus, which, however, differs in having the first seg- 

 ment shrunken and the abdomen not conic. We cannot say, 

 therefore, where the genus is to be limited. 



As to the conic form of the abdomen, it is met with in a great 



