(Stimpson, 1858)
Carapace somewhat quadrilateral, the dorsal surface depressed on posterior half but markedly vaulted down in anterior third. The regions are almost obliterated excepting the usual groove extending from the median frontal sinus toward the gastric region and also a small depression on either side of the cardiac region. The frontal and antero-lateral borders are furnished with very long silky hairs, the remainder of surface is also covered with velvety tomentum. On denudation, the surface near the frontal and antero-lateral borders is scattered with a few indistinct tubercles. The front rather straight, the median sinus very shallow and the lateral angle not markedly lobulated and not distinctly separated from the supraorbital angle. The first antero-lateral tooth is broad and truncate, usually bordered by a few granules; the second and third teeth obtusely pointed and bearing one or two granules, the last tooth very small.
The inner tooth of the infraorbital border is ventrally carinate and the surface near the infraorbital border granular. Chelipeds and ambulatory legs are very thickly fringed with long silky hairs; the wrist is sparingly granular on dorsal surface but thickly so near the distal end, its inner angle is produced into an obtuse tooth. The outer surface of palm is covered with fine granules but the surface near the base of the movable finger is more or less smooth and glabrous, especially in male. Immovable finger is deflected but curved inward at tip; the movable finger is dorsally granular. The merus of ambulatory legs is crested along the anterior border, carpus and propodus are more thickly furnished with hairs.
With regard to synonymy, Heteropilumnus angustifrons Alcock and Heteropilumnus cristata (Rathbun) are admitted as valid species although they were formerly regarded as synonyms of this species, while, Heteropilumnus cristadentatus Shen 1936 is quite identical with this species. (T. Sakai, 1939: 539)
Type locality: Shimoda, Japan.
Range: Japan - Shimoda (Stimpson, 1858b, 1907), Shimoda (Sakai, 1935), Shimoda, Wagu, Nanki Shirahama, and Kagoshima Bay (Sakai, 1939), Sagami Bay (Sakai, 1965b), Sagami Bay, Shimoda, Wagu, Kii Nagashima, Kii Minabe, and Kagoshima Bay (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Oga Peninsula (Muraoka, 1998); Korea - Cheju-do (Sakai, 1939, 1976), Cheju do and Jinsen (Kamita, 1941), Jag-yag Island and Hae-undae (Kim, 1973), Sinchang (Kim & Chang, 1985); China - Qingdao (Shen, 1936), Fujian and Zhejiang (Dai & Yang, 1991); shallow waters.