Serrata tenuis, Boyer, 2008

Boyer, Franck, 2008, The genus Serrata Jousseaume, 1875 (Caenogastropoda: Marginellidae) in New Caledonia, Mémoires du Muséum national d'Histoire naturelle 196, pp. 389-436 : 413-414

Serrata tenuis n. sp.

Fig. 36

TYPE MATERIAL. — Holotype (dd) MNHN 20617 .

TYPE LOCALITY. — Southern New Caledonia, 23°00’S, 167°29’E, 775 m [BIOCAL: stn DW 48] .

MATERIAL EXAMINED. — Southern New Caledonia. BIOCAL: stn DW 48, 23°00’S, 167°29’E, 775 m, 1 dd (holotype, Fig. 36) .

DISTRIBUTION. — Southern New Caledonia, one shell in 775 m.

DESCRIPTION. — Shell ovate fusiform, moderately solid, opaque. Protoconch paucispiral, wide, low, smooth. Spire tall, conical, whorls weakly convex. Aperture narrow, very oblique, slightly widening posteriorly, narrowed towards base. Base tapering. Outer lip thin, regular, subvertical. Shoulder sloping strongly, with 2 slight angles in the outline of the labrum, outer edge very weakly arched below shoulder, outer margin narrow, moderately thickened, rounded, weakly stepped, inner edge smooth. Four thin, subequal columellar plaits, anterior one very oblique, weakly angled in centre, 3 upper ones progressively less oblique, decreasing in size posteriorly, fourth plait nearly horizontal.

Ground colour whitish (faded).

Dimensions: 5.40 x 2.15 mm.

Radula unknown.

REMARKS. — Serrata tenuis is closely similar to S. carinata , particularly in its general fusiform outline, the fan-like arrangement of its columellar plaits, and its subvertical, smooth inner lip. It differs principally in its slightly more oval shell outline, its slightly more pointed spire, its less widened aperture, its more rounded base, and its rounded outer margin.

ETYMOLOGY. — Latin tenuis (adj., thin, delicate), referring to the thin outer lip of the shell and to its delicate appearance.