94 GENERA OF HYMENOPTERA. 



Nearly 200 sj)ecies have thus far been described as inhabiting our 

 fauna, about 30 of wliich are said to be identical with European 

 forms. Since the publication of Mr. Buckley's descriptive papers in 

 1866, only a few isolated species have been described ajs indigenous 

 to our country. 



For exceedingly interesting accounts of the habits of some of our 

 species, we are indebted to the observations of our esteemed friend 

 and co-laborer, the Rev. Dr. H. C. McCook, a list of whose published 

 writings will be given further on. 



The characters given in the following tables are compiled chiefly 

 from the second volume of Andre's admirable " Species des Hymen- 

 opt^res d' Europe," published in 1882-83. 



Famih FORMICID^. 

 Table of Genera. 



Workers and Females. 



Frontal carinas arising more or less near the posterior edge of the clypeus, which 

 does not extend back between insertion of antennse ; abdomen seen from 

 above shows five segments of which the last is conical and terminal, 

 orifice of anus small, circular, ciliated; wings J with one complete sub- 

 marginal cell 2. 



Frontal carinse arising at the angles or lateral edges of the clypeus, which is tri- 

 angular, usually rounded, extending more or less backward between 

 insertion of antennse : abdomen, viewed from above, shows only the first 

 four segments, the fifth being concealed under the preceding ; anus large, 



transverse, not ciliated 9. 



2. — Antennae 12-jointcd, inserted as near, or even nearer, to middle of frontal 

 carince than to their anterior extremity, and distant from posterior edge 

 of clypeus; clypeal fovere separated from antenna i fovea?; J without 

 ocelli 3. 



Antennai inserted near the anterior extremity of the frontal carina; and very 



near the po'sterior edge of clypeus 4. 



.3. — Clypeus trajK . idal. the sides diverging more or less anteriorly ; frontal 

 carina' «' 'ous in form of an S; head not obtuse or truncate in front; 

 scale of petiole oval, vertical, usually feebly and equally convex on its 

 two faces C'ampoiiotns Mayr. 



Clypeus with. parallel sides, only slightly diverging at anterior angles; an- 

 terior part of head forming an obtuse angle with the remainder of its 

 surface, or even sharply truncate ; scale square, thick, convex in front, 



flat behind and more or less emarginate above C'olobopsis Mayr. 



4. — Mandibles broad flat, triangular, apical margin dentate 5. 



Mandibles almost cylindrical, curved, very narrow, acute at tip. without 

 apical margin or trace of teeth ; frontal area well defined ; ocelli present ; 

 metathorax gibbous; scale thick, oval, vertical; wings 9 with one dis- 



- coidal cell Polyergns Latr. 



