Key to the species of the genus Labidodemas

1 Tables with large disc perforated by at least two circles of peripheral holes........................................ 2

- Tables with small discs without peripheral holes or with one circle of peripheral holes............................... 3

2 Tables with high spire....................................................................... L. maccullochi

- Tables with low spire or no spire.............................................................. L. americanum

3 Table crown> table disc................................................................................ 4

- Table crown <table disc................................................................................ 7

4 Table disc with very few or without peripheral holes......................................................... 5

- Table disc with one circle of peripheral holes............................................................... 6

5 Rim of table disc spiny, disc with four central holes; table crown with four long acute spines, occasionally bifurcated distally; buttons and pseudo-buttons absent in body wall; anal papillae absent............................... L. quadripartitum

- Rim of table disc very spiny, disc with four to five central holes; table crown with four to five long acute spines arranged in regular/overlapping; always bifurcated distally; buttons absent in body wall; pseudo-buttons present in body wall; anal papillae present..................................................................... Labidodemas javaensis sp. nov.

6 Rim of table disc spiny, disc with four to six central holes; table crown with four to five long spines most of them bifurcated distally; table crown> table disc; buttons present in dorsal body wall................................ L. semperianum

- Table disc smooth, disc with five to eight central holes; table crown with five to eight huge spines deeply bifurcated distally; table crown >> table disc (up to twice the diameter); buttons present in dorsal and ventral body wall.. L. pseudosemperianum

7 Table spire high, buttons present and smooth........................................................ L. rugosum

- Table spire low, buttons present or absent; if present, spiny.................................................... 8

8 Table disc with peripheral holes, buttons present; table crown very irregular............................... L. spineum

- Table disc nearly always without peripheral holes; buttons absent; table crown regular....................... L. pertinax