Alainthesius, Ng, Peter K. L. & Castro, Peter, 2016

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 106

Key to species of Alainthesius n. gen.

1. Dorsal surface of carapace almost smooth ( Figs. 20 C, D; 27D). G1 conspicuously short, stout ( Fig. 83 A, B) [ Madagascar]......................................................................................... A. signatus n. sp.

- Dorsal surface of carapace covered with small flattened granules ( Figs. 20 E–H; 27E, F). G1 relatively slender, with distal half elongated ( Fig. 83 D–G) [Papua New Guinea; New Caledonia; Fiji]................................ A. bertrandi n. sp.

Figures

FIGURE 20. Overall dorsal view of species of Megaesthesius and Alainthesius n. gen. A, Megaesthesius migmus n. sp., Philippines: holotype male 4.4 × 4.9 mm (NMCR); B, Megaesthesius migmus n. sp., Philippines: paratype female 3.9 × 4.5 mm (ZRC 2015.245); C, Alainthesius signatus n. sp., Madagascar: holotype male 2.5 × 3.3 mm (MNHN-IU- 2013 - 9472); D, Alainthesius signatus n. sp., Madagascar: paratype female 2.7 × 3.0 mm (MNHN-IU- 2013 - 9471); E, F, Alainthesius bertrandi n. sp., New Caledonia: holotype male 3.3 × 4.1 mm (MNHN-IU- 2013 - 9073); G, Alainthesius bertrandi n. sp., Papua New Guinea: female 5.6 × 6.9 mm (MNHN-IU- 2013 - 9012); H, Alainthesius bertrandi n. sp., New Caledonia: female 3.4 × 4.0 mm (MNHN-IU- 2013 - 9007).

FIGURE 83. Gonopods of species of Alainthesius n. gen. A ‒ C, A. signatus n. sp., Madagascar: holotype male 2.5 × 3.3 mm (MNHN-IU- 2013 - 9472) (after Crosnier 1975: fig. 1 f ‒ h); D ‒ H, A. bertrandi n. sp., New Caledonia: holotype male 3.3 × 4.1 mm (MNHN-IU- 2013 - 9073). A, ventral view of right G 1; D, ventral view of left G 1; B, dorsal view of right G 1; E, G, dorsal view of distal part of left G 1; F, ventral view of distal part of left G 1; C, right G 2; H, left G 2. Scales = 0.1 mm.