Cylichna consobrinoides Kuroda & Habe, 1952

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 660-661

Cylichna consobrinoides Kuroda & Habe, 1952

Figs 31E, F, 34, 35A, B

Cylichna consobrinoides Kuroda & Habe, 1952: 50 .

Cylichna consobrina A. Adams, 1862: 152 [non Cylichna consobrina Gould, 1859 ].

TYPE MATERIAL. — Not examined .

TYPE LOCALITY. — C. consobrina : west coast of Jesso , western Hokkaido, Japan . — C. consobrinoides: Mino-Sima [= Mishima], Japan, 115 m.

MATERIAL EXAMINED. — Coral Sea. CHALCAL 1: stn D Norfolk Ridge. MUSORSTOM 4: stn DW 225 , 22°52’S, 63, Banc Nova, 22°11’S, 159°14’E, 305 m, 1 dd . — MUSORS- 167°52’E, 590-600 m, 1 dd . — SMIB 3 : stn DW 21 , 22°59’S, TOM 5 : stn 255, Banc Capel , 25°15’S, 159°55’E, 280-295 167°19’E, 525 m, 1 dd . — SMIB 8 : stn DW 193-196 , 22 °59-23’S, m, 1 dd; stn 265, 25°21’S, 159°45’E, 190-260 m, 2 dd (Figs 168°21-23’E, 491-558 m, 1 dd.

35A, B); stn 291, Banc Argo, 23°08’S, 159°28’E, 300 m, 1 dd; New Caledonia proper. BATHUS 2 : stn DW 724 , Ile des Pins , stn 302, Banc Nova, 22°10’S, 159°23’E, 345-360 m, 1 dd; 22°48’S, 167°26’E, 344-358 m, 1 dd . — Grand Récif Sud , 200 m, stn 341, Chesterfield Islands, 19°46’S, 158°43’E, 620-630 5 November 1976, 1 dd .

m, 1 dd; stn 376, 19°51’S, 158°30’E, 280 m, 1 dd; stn 380, Loyalty Ridge. MUSORSTOM 6: stn DW 391, 20°47’S, 19°38’S, 158°44’E, 555-570 m, 1 lv, dissected (Figs 31E, F); 167°06’E, 390 m, 1 dd.

stn 388, 20°45’S, 160°54’E, 500-510 m, 5 dd. — CORAIL 2: Fiji. MUSORSTOM 10: stn DW 1376 , S of Viti Levu, 18°19’S, stn DE 16, Bancs Lansdowne-Fairway , 20°48’S, 160°56’E, 178°09’E, 497-504 m, 1 dd .

500 m, 1 dd. Tonga. BORDAU 2: stn DW 1531, Eua, 21°12’S, 174°56’W, 970- North of New Caledonia. BATHUS 4: stn DW 918, Grand Pas- 983 m, 1 dd.

sage, 18°49’S, 163°16’E, 613-647 m, 1 dd.

DISTRIBUTION. — Reported from the Japan Sea in 74-115 m (Hori 2000b). Records herein from the Coral Sea, Fiji, New Caledonia and Tonga (Fig. 34), in 200-970 m, live in 550-570 m.

DESCRIPTION. — Shell morphology. Length 17 mm, width 6 mm (largest specimen examined). Shell solid, elongate, with nearly parallel sides (Fig. 35A). Only 1 whorl visible, forming nearly the entire shell, with the exception of a small visible portion of the spire. Apex rounded, deeply umbilicate (Fig. 35B), with the aperture lip rising from the left side and forming a short, triangular wing. Anterior end of the shell rounded. Aperture as long as the shell, wider anteriorly and narrowing gradually at about 1/4 of its length. Columellar margin conspicuously thickened. Columella simple, with no folds. Umbilicus closed. Sculpture of about 5 simple spiral grooves near the posterior end and about 8 grooves near the anterior end. These grooves are absent from the central part of the shell, which is covered with faint growth lines. Colour uniform shiny white.

Anatomy. The digestive system contains 3 smooth gizzard plates similar in shape and size. All the plates are oval and elongate (Fig. 31F). The radular formula is 16 x 2.1.1.1. 2 in a specimen from the Coral Sea (MUSORSTOM 5 stn 380). The rachidian teeth are broad, with a number of sharp denticles decreasing in size towards the laterals of each plate (Fig. 31E). There is a gap with no denticles on the centre of each rachidian tooth. The innermost lateral teeth are hook-shaped, with a long, strong cusp with 15-20 denticles. The 2 outermost teeth of each row are much smaller, also hook-shaped and lack denticles.

Reproductive system unknown.

REMARKS. — Cylichna consobrina was described by A. Adams (1862) from Japan in 115 m, with no illustrations. Because this name was preoccupied by Cylichna consobrina Gould, 1859 , also from Japan, Kuroda & Habe (1952) proposed the replacement name Cylichna consobrinoides .

This species was redescribed and illustrated by Hori (2000b) who placed it in Adamnestia with no apparent justification. Iredale (1936) introduced the genus Adamnestia with a short description, for species similar to Cylichna and with a radula similar to that of Haminoea . Subsequent authors (Kuroda et al. 1971) broadened the concept of Adamnestia to include other species with a similar shell morphology to Adamnestia peroniana Iredale, 1936 , the type species. Anatomical examination of a specimen of C. consobrinoides shows that the radula morphology is similar to other species of the genus Cylichna , with a rachidian tooth, a large and denticulate innermost lateral tooth, and several smaller outer laterals. Therefore this species is maintained in the genus Cylichna .

Cylichna consobrinoides differs from other species of Cylichna here examined in having an elongate shell with the aperture lip rising from the left side and forming a short, triangular wing.