Rathbun, 1932
Closely resembles M. japonica, but the carapace is broader, the branchial regions being somewhat more swollen and the postorbital region also broader. The arrangement of the spines on the dorsal surface and also on margins of carapace is almost identical with that of M. japonica; the pseudorostral spines more slender and their outer borders subparallel in proximal half but divergent at tip. The three orbital spines are somewhat broader and leave no wide intervals between them. The fingers of the chelipeds unarmed. The ambulatory legs are more densely fringed with yellowish hairs, each segment is stouter than that of M. japonica, the carpus being distally broadened and its upper surface longitudinally sulcated. The characteristic anterior abdominal appendage was figured in my previous papers (1934, 1936). (Sakai, 1938: 299)
Type locality: Seno Umi, Japan.
Range: Japan - Toba, Shiono-misaki, Tanabe, Muroto-misaki, Tanegashima, Koshiki-jima, Ariake-kai, and Goto-retto (Yokoya, 1933), Manazuru and Hatsushima (Sakai, 1935), Manazuru and Nagasaki (Sakai, 1938a), Tosa Bay (Takeda & Miyake, 1969e), Sagami Bay (Sakai, 1965b), south off Tsushima (Takeda, 1973c), Sagami Bay, Kii Nagashima, Kii Minabe, Tosa Bay and Nagasaki (Sakai, 1976a), Sagami Bay (Griffin & Tranter, 1986a); Taiwan - (Dai & Yang, 1991), Tingch'ieting (Lin, 1949); South China Sea (Griffin & Tranter, 1986a); Vietnam - off Nha Trang (Serène & Lohavanijaya, 1973); Singapore; Western Australia; 50-540 m.