Sakai, 1935
The general outline of the carapace is hexagonal and is covered with flat granules everywhere. The front is almost straight and the posterior border not trilobed but perfectly straight, for the intestinal elevation scarcely projects beyond the posterior border.
Epibranchial ridges only are developed. They are furnished with several granules and run parallel to the antero-lateral borders of the carapace, which strongly incline anteriorly and posteriorly having these ridges as bordering line.
The longitudinal ridge is indistinct; it merely extends anteriorly to the meeting region of both epibranchial ridges, and is represented by several longitudinally arranged granules.
Antero-lateral borders indistinctly divided into three broad lobes; from the hind end of the first lobe, a very shallow groove runs inwards across the hepatic region.
Postero-lateral border concave; there is a patch of greenish brown mottle at the middle of this border in living individual.
Cheliped stout, merus has two elevations on the posterior border; carpus small, palm is strongly elevated in the middle of the upper border.
Ambulatory legs similar in shape, gradually decreasing in length from 1st to 4th.
Carapace 4 mm long, 5 mm broad, and the specimen is obviously larger than those described by Ihle. (Sakai, 1935)
Type locality: between Ito and Hatsushima, Sagami Bay, Japan, 80-100 m.
Range: Japan - Sagami Bay (Sakai, 1935, 1937, 1965), Amakusa and Sea of Ariake (Miyake et al., 1962), Tsushima Strait (Takeda, 1973c), between Ito and Hatsushima, Manazuru and Kii Minabe (Sakai, 1976a), Oshima Passage, Amami-Oshima (Takeda, 1989), Manazuru, Htsushima, Tosa Bay, Fukuoka and Amakusa (Muraoka, 1998), off Matsuyama, Seto Inland Sea (Takeda et al., 2000); East China Sea - north of Goto-retto (Takeda & Miyake, 1970a); 25-100 m.