Philomedes longidentata Chavtur, 1983: 22, 23, 25, 28, 39, 50– 51, fig. 10, 3– 10, table 2 (list); 1985: 58, 61, 62.
Distribution and Ecology. The species widely inhabits the subarctic waters of the northwestern Pacific at the salinity and temperature ranges of 33.4–33.9 ‰ and 0.6–12 ºC respectively (mainly muddy sand) (Chavtur 1983). In the East Sea (Sea of Japan) P. longidentatus was found (Fig. 1) in Peter the Great Bay (South Primorye, numerous samples collected between 42 º 30´– 42 º 50´N and 131 º 15 – 131 º 50´E) from 53 to 62 m (muddy sand, fine sand), in the Tatar Strait (51 º 21´N, 141 º 20´E; 50 º 49.4´N, 140 º 36.2´E; 50 º03.3´N, 141 º 28´E and 50 º00´N, 140 º 41.3´E) at a depth range of 43–145 m (muddy sand without or with an admixture of pebble and gravel), in the coastal waters of Monneron Island (46 º 17.8´N, 141 º 13.9´E; 46 º 17.5´N, 141 º 12.8´E and 46 º 15.2´N, 141 º 18´E) between 30–100 m (stone with sponges and bryozoans, broken shell and bryozoans) and near South Sakhalin (46 º 10´N) at 40 m (muddy pebble). It is known also for the Sea of Okhotsk (20–186 m) and Pacific Ocean from Hokkaido to Kamchatka (75–241 m).