(Rathbun, 1906)
The carapace is oval and not markedly convex; its dorsal surface is very distinctly separated into regions by deep furrows; each of the regions is not convex, being covered with flat pavement of granules; 1M is small but distinct and separated from the large entire 2M; the anterior end of 3M is not reached the anterior margin of 2M; of the antero-lateral regions 1L is small and more or less confluent with the external orbital angle, while 2 and 3L are fused to form a transverse areola that is shallowly and obliquely incised from the anterior margin; 4. 5 and 6L are distinctly isolated from each other, the areola 4L being the smallest; at the anterior end of the interregional furrow between 5 and 6L is demarcated a very small region; 1P is very prominent and transversely extended to the level of the lateral margin of 2M; at the middle of the posterior margin of 1P is a rounded process; 2P is deeply separated from 1P, being indistinctly subdivided into two areolets in the middle behind the posterior process of 1P. The front is composed of two lobes and a median U-shaped sinus; each lobe is most produced near the sinus and rather strongly retreats obliquely backwards; each of the lateral angle is almost fused with the supraorbital angle and with the ventral prolongation of the front.
The antero-lateral border of the carapace is armed with four teeth behind the external orbital angle; those teeth are subequal, convex and rounded at the summits.
The chelipeds are equal and not much long in the female; the outer surface of the carpus is more or less nodose with low prominences, its inner angle being armed with two large conical granules that are beaded to form several longitudinal series; the granules near the upper border are more prominent than those near the lower border; both fingers are short and hoof-form at the tips, the blackish brown colour of the immovable finger being extended a little onto the palm.
The ambulatory legs are very stout and densely covered with long, more or less brush-like hairs and with conical granules. (Takeda, 1972a)
Type locality: Laysan Island.
Range: Aldabra Islands (Guinot, 1964b, Serène, 1984); Chagos Archipelago - Salomon Island (Rathbun, 1911); Japan - Ishigaki-jima (Takeda, 1972a); China - Paracel Islands (Chen & Lan, 1978, Dai & Yang, 1991); Marshall Islands; Kiribati; Hawaiian Islands - Laysan Island (Rathbun, 1906), Johnston Island (Guinot, 1964b).