Key to the species of Alainodaeus (modified from Davie 1997)

1. Inner surface of palm of cheliped with a median and a ventral row of spinules; first anterolateral tooth clearly marked ............................................................................................................................... A. akiaki

- Inner surface of palm of cheliped without a median and a ventral row of spinules; first anterolateral tooth almost obsolete, represented at most by a few raised granules .................................................................. 2

2. Outer surface of palm of major cheliped entirely granular, although granules larger dorsally; 1 spine on inner surface of cheliped carpus; suture between abdominal somites 3 and 4 strongly marked across entire width; G1 (Davie 1997: figs. 4g, h) with extremely produced medial flange on inner face, tip fluted ......... ............................................................................................................................................................ A. alis

- Outer surface of palm of major cheliped entirely granular or, alternatively, only granular dorsally, becoming smooth over ventral half; 2 spines on inner surface of cheliped carpus; suture between abdominal somites 3 and 4 not strongly marked; G1 with moderate medial flange on inner face, tip bilobed ........... 3

3. Palm of major cheliped without a row of spines on inner superior margin, at most only with granules; G1 (Davie 1997: figs. 5i, j) short, stout, with concavity on proximal half of mesial margin ................ A. nuku

- Palm of major cheliped armed with a row of spines on inner superior margin; G1 longer, more slender. 4

4. Second anterolateral tooth sharp, prominent; mesial margin of ischium of 3rd maxilliped without row of

stiff setae; major terminal lobe of G1 (see Davie 1993: 520, figs. 6E, F, G) narrow, minor lobe obscure .... .................................................................................................................................................... A. rimatara - Second anterolateral tooth wide, low; mesial margin of ischium of 3rd maxilliped with row of stiff setae; major terminal lobe of G1 broad, spatulate, minor lobe small but prominent .................. A. filipinus n. sp.