Carcinoplax purpurea – Balss 1929: 24 (not Carcinoplax purpurea Rathbun, 1914).
Carcinoplax longimanus – Monod 1938: 143 [Red Sea] (not C. longimana (de Haan, 1833)).
Carcinoplax indica – Guinot 1969b: 524, figs 65-67, 75, 76 [discussion] [Red Sea].
Carcinoplax sp. 1 – Türkay 1986: 162 [Red Sea].
Carcinoplax sp. 2 – Türkay 1986: 162 [Red Sea].
Carcinoplax monodi Guinot, 1989: 279, figs 3, 8A-C, 9A-C, pl. 3, figs A-H [Red Sea].
Carcinoplax sp. (aff. monodi) – Guinot 1989: 283, fig. 10, pl. 3, figs I-K [Red Sea].
TYPE MATERIAL. — Mission R. Ph. Dollfus en Égypte, stn 2, ♂ holotype, cl 21.4 mm, cw 30.6 mm (MNHN-B 10272); 1 ♂ paratype, cl 17.8 mm, cw 25.1 mm (MNHN-B 10378); 1 pre-adult ♀ paratype, cl 8.5 mm, cw 13.0 mm (MNHN-B 10274); 3 ♂♂ paratypes (MNHN-B 10273).
TYPE LOCALITY. — Red Sea, Gulf of Suez, 29°35’- 29°48’N, 32°30’- 32°32’E, 36- 55 m.
MATERIAL EXAMINED. — Red Sea. Mission R. Ph. Dollfus en Égypte, stn 2, 29°35’- 29°48’N, 32°30’- 32°32’E, 36-55 m, 24.XI.1928, ♂ holotype (MNHN-B 10272). — Stn 24, 33°41’- 33°45’N, 27°48’- 27°55’E, 68-80 m, 30.XII.1928, 1 pre-adult ♀ paratype (MNHN-B 10378). — Stn 35, 29°38’- 29°45’N, 32°31’- 32°33’E, 40- 50 m, 26.I.1929, 1 ♂ paratype (MNHN-B 10378).
John Murray Expedition, stn A, 29°17.00’N, 32°43.00’E, 65-68 m, 6.IX.1933, 1 ♀ (BMNH 1984.245).
DISTRIBUTION. — Known only from the Red Sea (see Guinot 1989). Depth: 36- 562 m.
REMARKS
As in C. longimana and a few other Carcinoplax species, the carapace of C. monodi is globose and the anterolateral teeth disappear with increased carapace size. The first anterolateral tooth, however, is not well developed even in small individuals (Guinot 1989: fig. 9A-C). The carapace shape and the size and shape of the anterolateral teeth are similar to those of C. purpurea Rathbun, 1914, with which it has been confused in the past. Diagnostic of C. purpurea, however, is a purple-red band along the carapace from the front to the posterior border (see Hsueh & Huang 2002: fig. 8C). Carcinoplax purpurea is found in the western Pacific Ocean, whereas C. monodi lacks the purple-red band and is so far known only from the Red Sea. Unusual for a species of Carcinoplax is the large area of thoracic sternite 8 that is left exposed by the male abdomen (see Guinot 1969b: fig. 65; 1989: fig. 3).
A relatively small female variously identified as C. purpurea Rathbun, 1914 (Balss 1929: 24), Carcinoplax sp. 2 (Türkay 1986: 162), and Carcinoplax sp. (aff. monodi) (Guinot 1989: fig. 10, pl. 3, figs I-K) most probably belongs to C. monodi, an identification that should be verified when additional material becomes available.