Eusirus splendidus Chilton, 1912: 492, pl. 2, fig. 20. Eusirus perdentatus type marbré – Verheye, 2011: 94, pl. 1, figs A–B, pl. 2, figs A, C, E, G, I. Eusirus cplx perdentatus marbled – d’Udekem d’Acoz & Verheye, 2013: 59, 63, fig. 3.8.3A. Type material RV Pourquoi Pas?, dredging station 15, Palmer Archipelago, in front of Port-Lockroy [coordinates of Port Lockroy: 64°49′31″S, 63°29′40″W], chenal de Roosen [Neumayer Channel], 60–70 m, dredge, 26 November 1900: one ♀ holotype, MNHN AM 831 [only carcass part of appendages in alcohol; microscopic slides not retrieved]. Other material ANT-XIX/3–4, station lost: one sp., RBINS, INV. 132555, extr. EPE3. ANT-XXI/2, sta. 253-1, 71°04.89′S, 11°32.21′W to 71°04.30′S, 11°33.92′W, 295–309 m, 23 December 2003: one sp., RBINS, INV. 132562, extr. EC19, GenBank MT 985577 (COI), MT 945016 (CytB), MT 945034 (ITS2). – Same sta.: one sp., RBINS, INV. 132568, extr. EC23, GenBank MT 985580 (COI), MT 945018 (CytB), MT 945037 (ITS2). – Same sta.: one sp., RBINS, INV. 132571, extr. EC22, GenBank MT 985579 (COI), MT 945017 (CytB), MT 945036 (ITS2). – ANT- XXI/2, sta. 276-1, 71°6.44′S, 11°27.76′W to 71°6.64′S, 11°27.28′W, 268–277 m, 28 December 2003: one sp., RBINS, INV. 132519, extr. ED7, GenBank MT 985596 (COI). – Same sta.: one sp., RBINS, INV. 122643. – Same sta.: one sp., RBINS, INV. 132379-1 (carcass in alcohol) and 132379-2 to 132379-5 (four microscopic slides in Euparal). ANT-XXIII/8, sta. 604-1, 61°20.52′S, 55°09.72′W to 61°20.11′S, 55°07.26′W, 286–407 m, 19 December 2006: one sp., RBINS, INV. 132379-1 (carcass in alcohol) and 132379-2 to 132379-5 (four microscopic slides in Euparal). – ANT-XXIII/8, sta. 605-1, 61°20.35′S, 55°29.16′W to 61°19.98′S, 55°32.67′W, 146–151 m, 19 December 2006: one sp., RBINS, INV. 122646. – ANT-XXIII/8, sta. 611-1, 60°58.90′S, 55°11.31′W to 60°58.52′S, 55°07.82′W, 215– 297 m, 21 December 2006: one sp., RBINS, INV. 122639. – ANT-XXIII/8, sta. 642-1, 61°04.38′S, 55°59.81′W to 61°04.27′S, 55°58.88′W, 254 m, 27 December 2006: one sp., RBINS, INV. 132539, extr. ED28, GenBank MT 985587 (COI), MT 945021 (CytB), MT 945041 (ITS2). – ANT-XXIII/8, sta. 721-2, 65°55.41′S, 60°34.01′W to 65°55.79′S, 60°33.96′W, 295–299 m, 20 January 2007: one sp., RBINS, INV. 122633. – Same sta.: one ♀, RBINS, INV. 132538, extr. ED29, GenBank MT 985588 (COI), MT 945022 (CytB), MT 945042 (ITS2). – Same sta.: one ♀, RBINS, INV. 132517, extr. ED26, GenBank MT 985585 (COI), MT 945020 (CytB), MT 945040 (ITS2). – ANT-XXIII/8, sta. 726-1, 64°30.86′S, 56°40.23′W to 64°31.16′S, 56°40.51′W, 197–199 m, 22 January 2007: one sp., RBINS, INV. 122649. – ANT-XXIII/8, sta. 726-4, 64°37.83′S, 56°42.10′W to 64°38.03′S, 56°42.57′W, 292 m, 23 January 2007: one sp., RBINS, INV. 122636. – Same sta.: one sp. dissected and mounted on ten microscopic slides in Euparal, RBINS, INV. 132398-1 to 132398-10. ANT-XXIX/3, sta. 116-9, 62°33.79′S, 56°27.81′W to 62°33.71′S, 56°28.31′W, 248 m, 26 January 2013: two sps, RBINS, INV. 122857. – ANT-XXIX/3, sta. 185-3, 63°51.34′S, 55°41.11′W to 63°51.52′S, 55°41.43′W, 261– 296 m, 19 February 2013: ten sps, RBINS, INV. 122843. – ANT-XXIX/3, sta. 185-4, 63°51.53′S, 55°40.74′W to 63°51.53′S, 55°40.43′W, 253–258 m, 19 February 2013: eight sps, RBINS, INV. 122831. – ANT-XXIX/3, sta. 188- 4, 63°50.36′S, 55°37.42′W to 63°50.53′S, 55°37.52′W, 425–427 m, 20 February 2013: eight sps, RBINS, INV. 122850. – ANT-XXIX/3, sta. 193-8, 62°43.73′S, 57°29.04′W to 62°43.80′S, 57°29.40′W, 428–431 m, 23 February 2013: one sp., RBINS, INV. 138476, extr. MH3, GenBank MT 985628 (COI), MT 945023 (CytB), MT 945060 (ITS2). – Same sta.: one ♀, RBINS, INV. 122805A, extr. MH5, GenBank MT 985629 (COI), MT 945024 (CytB), MT 945061 (ITS2). – Same sta.: one sp., RBINS, INV. 122805B, extr. MH12, GenBank MT 985621 (COI), MT 945027 (CytB), MT 945053 (ITS2). – Same sta.: one ♀, RBINS, INV. 122805C, extr. MH10. – Same sta.: one sp., RBINS, INV. 122805D, extr. MH8, GenBank MT 985631 (COI), MT 945026 (CytB). – Same sta.: one sp., RBINS, INV. 122805E, extr. MH7, GenBank MT 985630 (COI), MT 945025 (CytB). – ANT-XXIX/3, sta. 193-9, 62°43.50′S, 57°27.92′W to 62°43.53′S, 57°28.28′W, 420–431 m, 23 February 2013: six sps, RBINS, INV. 122845. – Same sta.: two sps, RBINS, INV. 122859. – ANT-XXIX/3, sta. 197- 5, 62°44.73′S, 57°26.79′W to 62°45.05′S, 57°26.68′W, 258–273 m, 25 February 2013: ten sps, RBINS, INV. 122851. – Same sta.: five sps., RBINS, INV. 122855. – ANT-XXIX/3, sta. 197-6, 62°45.05′S, 57°26.68′W to 62°45.09′S, 57°26.47′W, 210–222 m, 25 February 2013: one sp., RBINS, INV. 122860. – ANT-XXIX/3, sta. 199- 4, 62°57.22′S, 58°14.60′W to 62°57.33′S, 58°14.95′W, 325–339 m, 27 February 2013: 17 sps, RBINS, INV. 122799. – Same sta.: three sps, RBINS, INV. 122808. – ANT-XXIX/3, sta. 204-2, 62°56.07′S, 57°58.14′W to 62°56.08′S, 57°58.51′W, 767–781 m, 28 February 2013: one sp., RBINS, INV. 122795. – ANT-XXIX/3, sta. 217- 6, 62°53.45′S, 58°13.06′W to 62°53.42′S, 58°13.41′W, 461–483 m, 2 March 2013: one sp., RBINS, INV. 122816. – ANT-XXIX/3, sta. 224-3, 63°0.53′S, 58°35.67′W to 63°0.58′S, 58°36.11′W, 257–261 m, 4 March 2013: two sps, RBINS, INV. 122813. R / V James Clark Ross, JR 144 (BIOPEARL I), Elephant Island, sta. EI-EBS-4- Supra, 61.33544°S, 055.20379°W to 61.33637°S, 055.20901°W, 270 m, 12 March 2006: one sp., INV. 138473, extr. EB8, GenBank MT 985572 (COI). – Same sta.: one sp., INV. 138474, extr. EB9, GenBank MT 985573 (COI). – Same sta.: one sp., INV. 138471, extr. EB10, GenBank MT 985570 (COI). CEAMARC sta. 01 (lot 2323), Adélie Coast, 66.003882 ° S, 142.313777 ° E to 65.99601° S, 142.35833°E, 228–240 m, 12 January 2008: one sp., MNHN-IU-2019-3361, extr. EE21, GenBank MT 985598 (COI), MT 945019 (CytB). Description (Based on female RBINS, INV. 132538; with reference to complementary illustrations of the holotype, MNHN AM 831). Body dorsal armature (Figs 6, 7A): Pereionites 5–7 and pleonites 1–3 with mid-dorsal carina backwardly prolonged into strong tooth; dorsal profile of pleonite 3 distinctly sigmoid. Epimeron 1 (Figs 5D, 14A): Narrow, tapering distally and posterodistally pointed, posteroventral margin nearly straight.