(Stimpson, 1858)
The anterior and antero-lateral surfaces of carapace, as well as the chelipeds and ambulatory legs are furnished with long and silky hairs, which are much more soft and flexible than those of Heteropilumnus ciliatus; remainder of the surface of entire animal is also covered with a coat of velvety tomentum. The dorsal surface of carapace is almost flat in posterior half but markedly vaulted down in anterior half.
The two frontal lobes are very shallowly divided by the median sinus, each lobe being moderately convex and the lateral angle only slightly lobulated. Antero-lateral borders are four-toothed, the first or the external orbital one is less prominent, the second and third ones are subequal and mounted with a few tubercles, that last one is very small and also mounted with one or two tubercles. The infraorbital border is straight and its inner angle not toothed. The basal segment is long for this genus and almost reaches the level of the inner orbital angle. The external maxillipeds differ apparently from the usual form of this genus, i.e., the ischium is much broadened at the base and the merus produced at inner distal angle, so that a wide rhomboidal median hiatus is left between the external maxillipeds in normal position.
The wrist and palm are granular beneath the tomentum and hair; the granules occur on entire outer surface of the palm and no smooth surface is left (at least in the female). The fingers are like those of Heteropilumnus ciliatus but the teeth of the cutting edges are very strong and erect, six in number in both cases. Merus of ambulatory legs is not at all crested, the carpus and propodus are especially thickly furnished with the long hairs aforementioned. (T. Sakai, 1939: 540)
Type locality: Amami-Oshima, Japan.
Range: Japan - Amami-Oshima (Stimpson, 1858b, 1907), north of Tanegashima (Yokoya, 1933), Gobo and Nagasaki (Sakai, 1939), Kii Peninsula, Nagasaki, Amami-Oshima and Yoron-jima (Sakai, 1976a), Mage-jima, Kagoshima Prefecture (Takeda, 1977b), Kakeroma-jima near Amami-Oshima (Takeda, 1989); coral reef to 154 m.