Diaphana sp.

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 647

Diaphana sp.

Figs 28A, 29

MATERIAL EXAMINED. — Loyalty Ridge. BIOGEOCAL: stn CP 260, 21°00’S, 166°58’E, 1820-1980 m, 1 lv, destroyed.

DISTRIBUTION. — Collected only in New Caledonia (Fig. 29), in 1820-1980 m .

DESCRIPTION. — Shell morphology. The single shell collected was partially broken and subsequently destroyed; length about 3 mm, width about 2 mm. Aperture as long as the shell, wider anteriorly and narrower posteriorly. Columella simple. Umbilicus wide and deep. Surface smooth, with no sculpture. Colour uniform whitish.

Anatomy. The radular formula is 8 x 1.0. 1 in the single specimen examined. Rachidian teeth plate-like. Lateral teeth with an elongate base and numerous denticles on the single, curved cusp (Fig. 28A).

REMARKS. — SchiØtte (1998) revised the genus Diaphana and concluded that there are 20 valid species, only one of them, Diaphana brazieri Angas, 1877 , found in the tropical Indo-Pacific. Diaphana brazieri differs from Diaphana sp. in having a more elongate shell with a smooth surface.

Diaphana sp. appears to be a distinct species but it is not named here because of the lack of a complete shell. The single collected shell, which was already damaged, was destroyed during the examination process, but the specimen is assigned to the genus Diaphana because of the presence of a radula with a single long and denticulate lateral tooth, and a rachidian tooth.