Note:  Do not rely on this information. It is very old.


Pterygogenea, the subdivision of Insects, including all those which have wings, or which, if wingless, such as the Fleas and Bird-lice, are descendants of winged forms. It thus includes all insects except the two members of the two small orders, the Collembola (q.v.) and Thysanura (q.v.), which are grouped together as the Apterycjogenea.