HYMENOPTERA. 233 



FAMILY I. 



HETEROGYNA. 



The first family of our second section is composed of two or three 

 kinds of individuals, the most common of which, the neuters and fe- 

 males, are apterous, and but rarely furnished with very distinct 

 ocelli. 



Their antennae are always geniculate, and the ligula is small, round- 

 ed and concave, or cochleariform. 



Some form communities, in which we find three kinds of indi- 

 viduals, of which the males and females are winged, and the neuters 

 apterous. In the two last the antennae gradually enlarge, and the 

 length of their first joint is at least equal to that of the third of the 

 whole organ; the second is almost as long as the third, and has the 

 form of a reversed cone. The labrum of the neuters is large, corne- 

 ous, and falls perpendicularly \inder the mandibles. 



These Hymenoptera compose the genus 



Formica, Lin. *, 



Or that of the ants, so highly celebrated for their foresight, and so 

 well known, some by their depredations in our houses, where they 

 attack our sugar and preserved viands, communicating to them at. 

 the same time a musky and disagreeable odour, and others by the in- 

 jury they do to our trees, by gnawing their interior in order to form 

 domicils for their colonies. 



The alidominal pedicle of these Insects is in the form of a scale or 

 knot, either double or single, a character by which they are easily 

 recognised. Their antennte are geniculate, and usually somewhat 

 largest near the extremity ; the head is triangular, Avith oval or 

 rounded and entire eyes, and the clypeus large ; the mandibles are 

 very strong in the greater nimiber, but vary greatly as to form in the 

 neuters ; the maxillae and labium are small ; the palpi are filiform, 

 and those of the maxillae the longest ; the thorax is compressed la- 

 terally, and the almost ovoidal abdomen furnished, in the females and 

 neuters, sometimes Avith a sting, and sometimes with glands in the 

 vicinity of the anus, that secrete a particular acid called formic. 



They form communities, which are frequently extremely numer- 

 ous. Each species consists of three kinds of individuals : males and 

 females, which are furnished with long wings, less veined than those 

 of the other Hymenoptera of this section, and very deciduous ; and 

 neuters, destitute of wings, Avhich are merely females Avith imperfect 

 ovaries. The males and females are merely found Avithin the do- 

 micil in transitu. They leave it the moment their Avings are de- 



* The tribe of the Formicari.«, Lat., Fatn. Nat. du R^gn. Anim., 452. 

 VOL. IV. R 



