(Hilgendorf, 1892)
The dorsal surface of carapace is quite flat and its aspect resembles that of Gaetice depressus, but the two postfrontal ridges are more sharply demarcated. There are also a pair of indistinct somewhat curved ridges, one each on antero-lateral surface of the protogastric region just inside the orbital fissure. The supraorbital angle is anteriorly sharply carinate. The surface of carapace near these carinae and ridges is imperfectly covered with minute pits or wrinkles. The front is marked with a deep median sinus, by which the free margin is divided into two arched lobes. Antero-lateral borders are cut into three sharp teeth, of which the external orbital one is largest and the third one is smallest; the lateral border behind the third tooth is well convergent backward. The stridulating organ of male is composed of three elongate crests and one tubercle. The external maxillipeds almost completely close the buccal cavern, the ischium is proximally narrowed, while the merus is not auriculated contrary to that of the genus Hemigrapsus, the inner and outer borders being not at all produced.
The chela of male is very high and swollen on outer surface, the inner surface is covered thickly with soft hairs; the immovable finger is curved inward at tip and the prehensile edge entire and smooth; the movable finger is slender and much curved, a prominent tooth occurs near its middle point and a few denticles near the distal end; the tips of these segments are only slightly hollowed. (T. Sakai, 1939: 675)
Type locality: Aden.
Range: Red Sea; Aden (Hilgendorf, 1892); Dar es Salaam (Hartnoll, 1975); Banda Aceh (de Man, 1895b, 1898); Cocos-Keeling Island (Serène & Umali, 1972); Japan - Amami-Oshima and Yoron-jima (Sakai, 1976a); Taiwan - Lan-Yü (Sakai, 1939), Lan-Yü and Kaohsiung (Lin, 1949); Samoa.