Alcomaja Ng & Forges 2015, n. gen.

Key to species of Alcomaja n. gen. 1. Dorsal surface of carapace and ambulatory legs densely covered with long, stiff setae (Fig. 17F); G1 almost straight with distinct ventral fold (Fig. 20R–T); Philippines.............................................................................................. Alcomaja desmondi n. sp. – Dorsal surface of carapace and ambulatory legs covered with scattered short, hooked setae, sometimes dense; G1 curved....................................................................................................2 2. Dorsal surface of carapace covered with small rounded granules, lateral and branchial spines strong even as adults, with 2 hepatic spines; adult ambulatory legs relatively short, with first leg of adult males not substantially elongated (Figs. 17A–E).........3 – Dorsal surface of carapace covered with small and large granules, sometimes sharp, lateral and branchial spines distinct but low to absent in adults, with 2 hepatic spines; adult ambulatory legs long, with first leg of adult males prominently elongated (Figs. 16A–E)..........................................................................5 3. Carapace relatively more elongate; pseudorostral spines long (Figs. 17E, 36O); G1 gently curved with distal part gently curved downwards (Fig. 20O–Q); Madagascar...................................................................................... Alcomaja miriky n. sp. – Carapace relatively broad; pseudorostral spines relatively shorter (Figs. 17A–D, 36M, N); G1 similar to above or otherwise..4 4. Intercalated spine acutely triangular (Fig. 36M); G1 strongly curved, with distal part gently curved downwards (Fig. 20A–J); Japan and Taiwan................................................................................................... Alcomaja nagashimaensis (T. Sakai, 1969) – Intercalated spine basally subquadrate (Fig. 36N); G1 gently curved, with distal part gently curved upwards (Fig. 20K–M); Solomon Islands................................... Alcomaja latens n. sp. 5. Dorsal surface of carapace with distinct small and large sharp and rounded granules; intercalated tooth triangular (Figs. 16D, E, 18A, B); G1 gently curved, distal part relatively short (Fig. 19G); Moluccas and Western Australia......................................................... Alcomaja confragosa (Griffin & Tranter, 1986) – Dorsal surface of carapace as above or otherwise (Figs. 16A–C, 18C–F); intercalated tooth subtruncate basally (Fig. 18C–F): G1 gently or strongly curved..................................................6 6. Dorsal surface of carapace with distinct small and large sharp, rounded granules (Figs. 16B, C, 18C, D); pseudorostral spines with rounded cross-section (Fig. 18C, D); ischium of third maxilliped distinctly granular (Fig. 45B, C); G1 gently curved, distal part straight (Fig. 19D–F); South China Sea and Philippines............... Alcomaja gracilipes (Chen & Ng, 1999) – Dorsal surface of carapace with small and large rounded granules, some of which merge basally (Figs. 16A, 18E, F); pseudorostral spines dorsoventrally flattened (Fig. 18E, F); ischium of third maxilliped smooth (Fig. 45A); G1 strongly curved, distal part curved upwards (Fig. 19A–C); Philippines........................................................... Alcomaja irrorata n. sp. Published as part of Ng, Peter K. L. & Forges, Bertrand Richer De, 2015, Revision of the spider crab genus Maja Lamarck, 1801 (Crustacea: Brachyura: Majoidea: Majidae), with descriptions of seven new genera and 17 new species from the Atlantic and Indo-West Pacific, pp. 110-225 in Raffles Bulletin of Zoology 63 on page 145, DOI: 10.5281/zenodo.5384590