HYMENOPTERA. 235 
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 antenne 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 antennz 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 under 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 abdominal 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 antennz are geniculate, and usually somewhat 
largest near the extremity; the head is triangular, with oval or 
rounded and entire eyes, and the clypeus large; the mandibles are 
very strong in the greater number, but vary greatly as to form in the 
neuters ; the maxille and labium are small; the palpi are filiform, 
and those of the maxille the longest; the thorax is compressed la- 
terally, and the almost ovoidal abdomen furnished, in the females and 
neuters, sometimes with 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, which are merely females with imperfect 
ovaries. The males and females are merely found within the do- 
micil in transitu. They leave it the moment their wings are de- 
* The tribe of the FormMicari®, Lat., Fam, Nat. du Régn. Anim., 452. 
VOL. IV, R 
