The taxonomy of spider crabs of the genera Eurynome, Choniognathus, Seiitaiodes and Kasagia (Crustacea: Brachyura: Majidae) from southwest Indian Ocean Author Forges, Bertrand Richer De 0000-0002-4554-7953 b.richerdeforges@gmail.com Author Lee, Bee Yan Author Ng, Peter K. L. 0000-0002-4554-7953 b.richerdeforges@gmail.com text Zootaxa 2021 2021-10-07 5048 3 301 333 journal article 4058 10.11646/zootaxa.5048.3.1 6cf7dece-9a31-4cba-9497-664a0ffac9d8 1175-5326 5556341 951BE302-C0BF-4AA3-AE12-BBAC4EDEBAFB Genus Eurynome Leach, 1814 Eurynome Leach, 1814: 431 .— Monod, 1956: 32 (list), 480 (list).— Hartnoll, 1961: 172 , 173.— Griffin, 1964: 196 .— Griffin, 1966b: 42 , 43.—Ingle. 1980: 48 (key), 136.— Griffin & Tranter, 1986: 200 (key), 205.—Manning & Holthuis, 1980: 253 (list), 311 (list). Type species. Cancer asper Pennant, 1777 , by monotypy. Diagnosis. Carapace pyriform. Pseudorostral spines of various lengths, diverging with V-shaped cleft, dorsoventrally flattened, gently concave on both surfaces. Dorsal surface of carapace covered by small and large boletiform tubercles; some tubercles coalescent on gastric, cardiac, branchial and intestinal regions, forming small plates. Supraocular eave wide forming tooth on proximal part; narrow gap between supraocular eave and postocular spine, without visible intercalary spine. Hepatic region with triangular auriculiform lobe. Branchial region with strong, blunt spine; 1 epibranchial spine flattened, curved, directed upwards and posteriorly. Eye retracts deep into orbit. Basal antennal article triangular, basally large, forming lobe on proximal part of orbit. Epistome wider than long. External angles of buccal frame flattened, plate-like. Border of pterygostome with row of 3 or 4 large granules. Third maxilliped ischium not fused with merus. Anterior part of male thoracic sternum deeply depressed, with 4 large boletiform granules; anterior margin of sternopleonal cavity with large plate on each side. Cheliped long, surfaces covered with flattened granules, fingers short curved, gently granulated. Ambulatory legs short, upper border of meri carinate. G1 long, curved with a strong subterminal projection, hook-like, distal part densely setose. G2 short, without elongate distal segment. Remarks. The concept of Eurynome has changed substantially over the years, with many species previously ascribed to this taxon moved to other genera (see Griffin & Tranter 1986 ; Richer de Forges & Ng 2007 ). The genus as understood today is restricted to the eastern Atlantic, the Indian Ocean shores of South Africa , New Zealand and Samoa , with the following recognised species: E. aspera ( Pennant, 1777 ) (= E. scutellata Risso, 1827 ; E. boletifera Costa, 1838 , E. longimana Stimpson, 1857 ; E. aspera var. acuta A. Milne-Edwards & Bouvier, 1900 ); E. bituberculata Griffin, 1964 ; E. erosa A. Milne-Edwards, 1873 ; E. parvirostris Forest & Guinot, 1966 ; and E. spinosa Hailstone, 1835 (= E. tenuicornis Malm, 1861 ) ( Ng et al . 2008 ; Ahyong 2008 ; present study).