Paraplatyarthrus

Key to species of Paraplatyarthrus from Western Australia *

1. Maxilla 2 with no delimiting line between lobes (see Fig. 17 E)................................... P. pallidus sp. nov.

- Maxilla 2 with delimiting line between lobes (see Fig. 5 F).................................................... 2

2. Eyes absent (no ommatidia present) (see Fig. 2 H)................................................ P. subterraneus

- Eyes present or significantly reduced (1–5 ommatidia present).................................................3

3. Male genital papilla apically truncated (Fig. 9 C); eyes with 1 very reduced orange ommatidium-like component (Fig. 2 C)...................................................................................... P. cunyuensis sp. nov.

- Male genital papilla apically rounded (Fig. 19 A); eyes with 3–5 black ommatidia................................. 4

4. Cephalic lateral lobes enlarged (Fig. 11 H); male pleopod 1 exopodite with posterior point developed (Fig. 13 B)................................................................................................. P. nahidae sp. nov.

- Cephalic lateral lobes small (Figs. 2 E–F); male pleopod 1 exopodite with no or a weak posterior point (Fig. 16 B)........ 5

5. Eyes with 3 ommatidia............................................................ P. occidentoniscus sp. nov.

- Eyes with 5 ommatidia............................................................. P. crebesconiscus sp. nov. (* P. australiensis could not be included in the key due to a lack of material)