Key to the species of the Macrophthalmus convexus group (adapted from Barnes, 2010; Davie, 2012; Shih et al., 2015)

1. Chelae large and elongate, with clearly differentiated teeth on cutting margins of fingers .......................................................2

– Chelae small and feeble (as in those in female Macrophthalmus), with poorly differentiated or no teeth on cutting margins of fingers ......................................................................................3

2. Lateral margin of carapace with three anterolateral teeth (including external orbital angle); G1 with apical portion not truncated, armed with one short, arched chitinous process; posterior margin of propyloric ossicle of median tooth plate with wide and nearly flat shape, lateral tooth plate with 13–14 teeth, anterior tooth short and stout............. M. (M.) convexus

– Lateral margin of carapace with two anterolateral teeth (including external orbital angle); G1 with apical portion truncated, armed with C-shaped chitinous process; posterior margin of propyloric ossicle of median tooth plate with narrow and acute shape, lateral tooth plate with 15–16 teeth, anterior tooth short and slender......... M. (M.) manggala, new species

3. Fixed finger of male with long, low tooth along proximal half of cutting margin; apical portion of G1 not truncated, armed with one pointed chitinous process ......... M. (M.) parvimanus

– Fixed finger of male with small, distinct quadrangular tooth on median of cutting margin; apical portion of G1 truncated, without chitinous process........................ M. (M.) consobrinus