Abstract
Protura are known all over the world with more than 800 described species belonging to three different orders (Acerentomata, Sinentomata, and Eosentomata) and seven families (Hesperentomidae, Protentomidae, Acerentomidae, Fujientomidae, Sinentomidae, Eosentomidae, and Antelientomidae). At present 76 genera are known worldwide. In this paper a description of the diagnostic characters of these genera and an updated key for their identification are reported.