Key to the species of the subgenus Eurythosia (based on male genitalia)

The following keys do not include Archithosia jaundeana, as the holotype lacks the abdomen and its genitalia are unknown; see also the Discussion. Characters in the key are shown by arrows in Table 1.

1 Ala valvae with saccular distal process bent inwards and well developed......................................... 2

- Ala valvae with saccular distal process absent or barely visible......................................... A. derelicta

2 Ala valvae with a strong median process bent inwards.............................................. A. kinuthiae

- Ala valvae without such a process........................................................................ 3

3 Supravalva with a strong medially arising costal process........................................... A. angulifascia

- Supravalva without such a process........................................................................ 4

4 Distal process of the ala valvae as long as 1/3 of the entire ala valvae................................. A. makomensis

- Distal process of the ala valvae as long as 1/4 of the entire ala valvae............................... A. henricus n. sp.