Relichna sp. 2

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 765-767

Relichna sp. 2

Figs 88G, H, 90

MATERIAL EXAMINED. — North of New Caledonia. MUSORS- TOM 4 : stn DW 159 , 18°46’S, 163°16’E, 585 m, 1 dd .

Loyalty Islands. CALSUB: pl. 15, between Lifou and Uvea, 20°37’S, 166°58’E, 538 m, 1 dd.

New Caledonia proper. BIOGEOCAL: stn KG 201, 22°40’S , Vanuatu. MUSORSTOM 8: stn DW 972 , 19°22’S, 169°28’E, 487- 166°33’E, 595 m, 1 dd; stn KG 219, 22°39’S, 166°34’E, 570 507 m, 1 dd; stn DW 1045 , 16°54’S, 168°20’E, 459-488 m, 10 m, 1 dd . — BATHUS 2 : stn CP 760, Passe de Dumbéa , 22°19’S, dd (Figs 88G, H); stn DW 1048 , 16°40’S, 168°04’E, 450-489 m, 166°11’E, 455 m, 1 dd . — BATHUS 1 : stn DE 697, Passe de Hien- 1 dd .

ghène, 20°34’S, 164°58’E, 570-650 m, 1 dd; stn CP 698, 20°34’S, Wallis Island. MUSORSTOM 7: stn DW 523,, 13°12’S, 164°57’E, 491-533 m, 1 dd. 176°16’W, 455-515 m, 17 dd; stn DW 601, 13°19’S, 176°17’W, Fiji. MUSORSTOM 10: stn CP 1366, South of Viti Levu, 18°12’S, 350 m, 12 dd.

178°33’E, 149-168 m, 1 dd. — BORDAU 1 : stn CP 1468, 18°16’S, Tonga. BORDAU 2 : stn DW 1569 , NW of Tongatapu, 21°02’S, 178°41’W, 478-500 m, 1 dd. 175°19’W, 433 m, 1 dd .

DISTRIBUTION. — Collected from Fiji, New Caledonia, Tonga, Vanuatu and Wallis Island (Fig. 90), in 168-595 m.

DESCRIPTION. — Shell morphology. Length 8 mm, width 4 mm (largest specimen examined). Shell solid, oval, wider medially (Fig. 88G). Only 1 whorl visible, forming nearly the entire shell, except for a small visible portion of the top of the spire. Apex rounded, deeply umbilicate (Fig. 88H), with the aperture lip rising from the left side and forming a very short wing, which is connected to the columellar margin. Anterior end of the shell rounded. Aperture as long as the shell, wider anteriorly and narrowing gradually at about 1/3 of its length. Columellar margin slightly thickened. Columella with an inconspicuous fold in some specimens. Umbilicus closed. Sculpture of a number of thin spiral lines arranged next to each other. Near the anterior end of the shell there are 7-9 more conspicuous spiral lines clearly separated from each other. Colour uniformly dirty white.

Anatomy. Unknown. All shells collected lacked soft parts.

REMARKS. — The anatomy of this species is unknown so it is here referred to Relichna on the basis of its conchological similarities to other species of the genus here described, pending availability of anatomical information.

Relichna sp. 2 resembles Relichna venustula (A. Adams, 1862) in having sculpture of numerous spiral grooves on the entire shell. However, the shells of Relichna sp. 2 are shorter, more oval and have a wider aperture. These differences may represent intraspecific variation, so this species is not named here until complete specimens become available, permitting anatomical comparisons.