Roxania pacifica (Habe, 1955)

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 696

Roxania pacifica (Habe, 1955)

Figs 53B, 54

Abderospira pacifica Habe, 1955: 70 , pl. 4, fig. 30

TYPE MATERIAL. — Not examined .

TYPE LOCALITY. — Off Tosa , Shikoku, Japan .

MATERIAL EXAMINED. — Philippines. ESTASE 2: stn CP 2, 830 m, 1 dd .

14°05’N, 120°02’E, 2050 m, 1 dd. Vanuatu. MUSORSTOM 8: stn DW 1045, 16°54’S, 168°20’E, Indonesia. KARUBAR: stn DE 55, Tanimbar Island, 08°16’S, 459-488 m, 1 dd.

131°47’E, 852-854 m, 1 dd; stn CP 91, 08°44’S, 131°05’E, 884- Fiji. BORDAU 1: stn CP 1396, 16°39’S, 179°57’E, 591-596 m, 891 m, 1 dd. 1 dd (Fig. 53B); stn CP 1398, 16°22’S, 179°56’E, 907-912 m, 1 New Caledonia proper. BATHUS: 1: stn CP 671, Passe du Cap dd; stn DW 1485, 19°03’S, 178°30’W, 700-707 m, 1 dd.

Baye, 20°51’S, 165°28’E, 450-470 m, 1 dd. Tonga. BORDAU 2: stn DW 1508, Tongatapu, 21°02’S, 175°19’W, Norfolk Ridge. BIOCAL: stn DW 49, 23°03’S, 167°32’E, 825- 555-581 m, 1 dd.

DISTRIBUTION. — Originally described from Japan (Habe, 1955). Here reported from Indonesia, the Philippines, Fiji, New Caledonia, Tonga and Vanuatu (Fig. 54), in 470-2050 m.

DESCRIPTION. — Shell morphology. Length 9 mm, width 7 mm (single specimen examined). Shell solid, almost rounded, with convex sides (Fig. 53B). Only 1 whorl visible, forming the entire shell. The protoconch is completely embedded within the outer whorl. Apex rounded, depressed, not umbilicate. The aperture lip rises slightly over the apex. Anterior end of the shell rounded. Aperture as long as the shell, wider anteriorly and narrowing abruptly at about 1/2 of the aperture length. Columellar margin conspicuously thickened, with a wide lip on the anterior end of the aperture. There is no distinct callus. Sculpture of several punctuated spiral grooves, more densely concentrated towards the posterior end. Near the apex the punctuations are larger and more densely arranged. Colour uniform cream.

Anatomy. Unknown. All shells collected lacked soft parts.

REMARKS. — Habe (1955) described Roxania pacifica in Abderospira , based on an unstated number of specimens collected from Tosa Bay, Japan, at an unknown depth. Hori (2000b) published a photograph of the shell. Roxania pacifica is distinguishable from other members of the genus by its rounded shape, with the columellar margin conspicuously thickened, and the sculpture of punctuated spiral grooves, more densely concentrated towards the posterior end of the shell.