Toledonia epongensis, Valdés, 2008

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 650-651

Toledonia epongensis n. sp.

Figs 28E-G, 29

TYPE MATERIAL. — Holotype MNHN 20337 and 14 paratypes MNHN 20338-20339, 3 paratypes LACM 2990 .

TYPE LOCALITY . — Mont B, Banc Éponge, Norfolk Ridge, 24°55’S, 168°22’E, 508-532 m [ SMIB 8 : stn DW146-147 ] .

MATERIAL EXAMINED. — Norfolk Ridge. SMIB 8 : stn DW 146- 167°43’E, 433-450 m, 1 dd, paratype (MNHN 20338); stn DW 147 , Mont B, Banc Éponge, 24°55’S, 168°22’E, 508-532 m, 14 169, Banc Stylaster, 23°37’S, 167°42’E, 447-450 m, 3 dd, paradd & lv, holotype (MNHN 20337; Figs 28F, G) and paratypes types ( LACM 2990 ) .

(MNHN 20339; Figs 28E); stn DW 166, Banc Stylaster, 23°38’S,

DISTRIBUTION. — Collected only from the Stylaster and Eponge Banks in New Caledonia (Fig. 29), in 450-508 m, live in 508-532 m.

DESCRIPTION. — Shell morphology. Length 1.5 mm, width 1 mm (holotype). Shell fragile, oval, elongate, with the external lip of the aperture concave (Fig. 28F). Spire elevated, conical, with 2 whorls (Fig. 28G). Body whorl large, about 3/4 of the shell length. Anterior end of the shell rounded. Aperture short and narrow, approximately 4/5 of the body whorl length, wider anteriorly and narrowing abruptly at about 1/2 its length. Columella slightly twisted. Umbilicus wide and deep. Shell smooth with no sculpture. Colour uniform whitish.

Anatomy. The radular formula is 22 x 1.1. 1 in the single specimen examined from New Caledonia (SMIB 8 stn DW 146-147). The rachidian teeth are broad, with a concave and wide base, and 12 short cusps, the more lateral ones being shorter than the rest (Fig. 28E). Lateral teeth plate-like, with no denticles.

REMARKS. — Toledonia epongensis clearly differs from Toledonia neocaledonica n. sp. in shell morphology. Whereas the shell of T. neocaledonica has a flat apex, with the aperture ending at the same level on the left side and an involute spire, in T. epongensis the spire is conical and elevated. There are no other Indo-Pacific species in the genus.

This species is placed in Toledonia based on the radular morphology, which has a denticulate rachidian tooth and a plate-like, smooth lateral tooth on each side.

ETYMOLOGY. — After the Eponge Bank, southern New Caledonia, where the holotype was collected .