(Flipse, 1930)
This species differs from Parthenope beaumontii only in the following few characters:
1. Carapace regularly triangular, dorsal surface almost smooth and pitted but not granulated excepting a few granules scattered near the postero-lateral borders. No tubercles on gastric, cardiac and branchial regions.
2. Rostrum very obscurely and unevenly trilobate. The margins of supraocular eave and the postocular lobe are almost continuous and are finely denticulated. No postocular constriction, the postocular lobe being continuous with the hepatic margin. The antero-lateral border, including the hepatic margin, is armed with 14 or 15 denticulated teeth, of which the last one is not especially enlarged as in the former species. In other respects this species resembles Parthenope beaumontii. (Sakai, 1938: 338)
Type locality: Sulu Archipelago, "Siboga" stn 109, 13 m.
Range: Japan - Hatsushima, Sagami Bay (Sakai, 1935), between Ito and Hatsushima (Sakai, 1938a), Sagami Bay and Kii Minabe (Sakai, 1976a); Sulu Archipelago (Flipse, 1930); 13-50 m.