Key to males of the genus Xenos from the Neotropics

Out of a total of 18 species of Xenos described so far from the Neotropics, only 6 males are known, the rest of the species were described from females. A key to only 5 males is given below since X. bonairensis was described without its head or prothorax (Brèthes 1923).

1. Palpus of maxilla absent................................................................................................ 2

­ Palpus of maxilla present .............................................................................................. 4

2. Maxilla as long as mandibles ........................................................ occidentalis (Brazil)

­ Maxilla shorter than mandibles ..................................................................................... 3

3. Maxilla a fourth shorter than mandibles; of equal width throughout ending with a blunt apex ................................................................................................ fluminensis (Brazil)

­ Maxilla an eighth shorter than mandibles; basal third wide and narrows to tip.............. .................................................................................................................. zikani (Brazil)

4. Basal segment and palpus of maxillae of equal length ................... indespectus (Brazil)

­ Basal segment longer than palpus ................................................................................ 5

5. Basal segment of maxilla two thirds the length of palpus; palpus does not fit into socket in basal segment .......................................................................bohlsi (Paraguay)

­ Basal segment of maxilla twice the length of palpus; palpus fits into a socket in the basal segment ......................................................................... hamiltoni sp. n. (Mexico)