Kaasichiton lukini (Sirenko, 1990) n. comb.

(Figures 1–5)

Leptochiton lukini n. sp.; Sirenko 1990: 97, figs 1, 3, 11.

Leptochiton (Leptochiton) lukini; Kaas & Van Belle 1994: 17, fig. 5, map 50.

Type material. Holotype (ZIN 1919) and 5 paratypes (ZIN 1920).

Type locality. Kurile Islands, Chirpoy Island (holotype), 20 m.

Material examined. A total of 19 specimens. Kurile Islands, R/V Krilatka, Urup Island, the Okhotsk Sea, Schukin Inlet, SCUBA, sample 41, 20 m, stones, 1 spm, BL 3.5 mm, 08.09.1969 ; Van-der-Lind Cape, SCUBA, sample 65, 20 m, stones, 5 paratypes, (ZIN 1920), BL 3.0–4.0 mm, 09.09.1969 ; Temniy Cape, SCUBA, sample 136, 15 m, stones, 1 spm, BL 4.0 mm, 18.09.1969 ; Temniy Cape, SCUBA, Khiva Cape, SCUBA, sample 152, 20 m, stones, 1 spm, BL 3.5 mm, 21.09.1969 ; Etolin Cape, SCUBA, sample 167, 10 m, stones, 1 spm, BL 3.0 mm, 23.09.1969 ; Kalashnikov Cape, SCUBA, sample 168, 10 m, stones, 1 spm, BL 4.0 mm, 23– 24.09.1969 ; Urup Island, Tair Island, SCUBA, sample 756, 20 m, rocks, 1 spm, BL 3.0 mm, 18.09.1970 ; Urup Island, Kitoviy Cape, SCUBA, sample 1058, 20 m, stones, 4 spms, BL 3.0–4.0 mm, 12.10.1973 Iturup Island, Urumpet Cape, trawl, sample 199, 51– 44 m, pebble and shells, 2 spms, BL 4.0 mm, 06.10.1969 ; Chirpoy Island, SCUBA, sample 538, 20 m, stones, holotype, (ZIN 1919) BL 4.0 mm, 04.09.1970 ; Simushir Island, Polanskogo Cape, SCUBA, sample 645, 20 m, stones, 1 spm, BL 3.5 mm, 10.09.1970 ;

Distribution. Pacific Ocean, Kurile Islands, Iturup, Urup, Simushir and Chirpoy islands, 10– 44 m.

Remarks. When describing this species, Sirenko (1990) noted that this species had juveniles in the pallial groove.At the beginning of September, a female with 4 eggs in the pallial groove was encountered near Urup Island. The eggs were relatively large, (about 400 µm in diameter) compared to the eggs of chitons not brooding in pallial groove (Sirenko 2015).