The chitons of the family Leptochitonidae (Mollusca: Polyplacophora) from the Emperor Seamounts, Pacific Ocean Author Sirenko, Boris text Zootaxa 2024 2024-07-02 5474 5 522 532 http://dx.doi.org/10.11646/zootaxa.5474.5.4 journal article 299716 10.11646/zootaxa.5474.5.4 ce52c1e1-a0fa-4124-8253-ce62e62ad02d 1175-5326 12730823 189347B3-7151-45FB-9240-8CF3B820766C Leptochiton antarcticus Sirenko, 2015 Leptochiton antarcticus Sirenko, 2015a: 139 , figs 1–7; 2019b: 71, Figs 1–3 . Type material. Holotype (ZISP 2250); 2 paratypes (ZISP 2251, 2252). Type locality. Southern Ocean , Scotia Sea , off South Sandwich Islands , 59°42.0’S , 28°12.9’W , 142–160 m , gravel, mud . Remarks. Besides the widespread specimens known from the slopes of Antarctica , the only other report of a specimen of this species was found on the slope of Nintoku Seamount ( Sirenko 2019b ). Externally, L. antarcticus differs little from the other two species of the Emperor Seamounts ( Leptochiton milwaukensis n. sp . and Belknapchiton belknapi ). Like these species, L . antarcticus also has tegmentum granules arranged quincuncially on the head valve, lateral areas of intermediate valves and postmucronal area of tail valve and the dorsal scales have longitudinal ribs. Leptochiton antarcticus differs from L. milwaukensis n. sp. by having 5 round pores of aesthetes in granules of the tegmentum ( vs. 3 pores, 2 of them slit-shaped in L. milwaukensis n. sp. ). The shape of the central teeth of the radula is also very different in these two species. Leptochiton antarcticus differs from Belknapchiton belknapi by having 5 aesthetes in granules of the tegmentum ( vs . 3 aesthetes in B. belknapi ) and 12–16 longitudinal ribs on the dorsal scales ( vs . 1–3 ribs in B. belknapi ). The shape of the central teeth of the radula is very different in these two species.