Diagnosis. Shell of medium size, biconic-fusiform, brownish-grey in colour, usually with brown spots and bands on subsutural fold, peripheral keel, and shell base. Protoconch multispiral, protoconch I of 1.75 minutely granular whorls, protoconch II of 1.5 whorls with arcuate axial ribs. Microsculpture of the protoconch consists of minute granules arranged in spiral and, on the lower part of the whorls, oblique rows. Subsutural fold of about the same width as the peripheral keel, and gemmulate. Spiral cords on the shell base are rather distant from each other, often granular. Columellar pleat distinct to almost obsolete. Anal sinus deep. U-shaped.

Description of holotype. The shell is biconic-fusiform and rather thick and strong. The protoconch is dark-brown and consists of minutely granular protoconch I (partly broken) and protoconch II of 1.5 whorls covered by arcuate and strongly oblique axial ribs, which do not reach the lower suture. Ribs become more distant from each other towards the transition from proto- to teleoconch. Interspaces between ribs are very finely spirally striated. The teleoconch consists of 8 3/4 low whorls separated by deeply channelled sutures. The profile of spire is initially flat, but then becomes slightly convex. Whorls bear a wide subsutural fold and a strong peripheral keel. The subsutural fold is narrower than the keel on initial teleoconch whorls, but rapidly widens and already on 4th-5th whorls it becomes of about the same width. Both sculptural elements become more flattened towards the body whorl. They are covered by gemmules which have the shape of blunt tubercles on initial whorls but become longitudinal and more obsolete towards the body whorl. Gemmules on the subsutural fold also become oblique, whereas those on the peripheral keel become arcuate. The number and position of gemmules on the subsutural fold more or less correspond to those of the peripheral keel. There are 22 gemmules on the penultimate whorl and about 30 on the body. Both subsutural fold and peripheral keel of last whorls bear two indistinct spiral cords forming tubercles at intersection with gemmules. The upper edge of the peripheral keel also bears a strong and wavy spiral cord bordering the deeply excavated interspace between the keel and subsutural fold. The keel on initial whorls is set close to the lower suture, and the distance between the suture and the keel is approximately the same as between the keel and subsutural fold. However the keel position becomes higher towards the body whorl, and on the penultimate whorl the keel is rather distant from the suture. A weak cord below the keel appears on 5th—6th whorls; 4 additional cords develop on the penultimate whorl. The body whorl occupies about 60% of the shell height. Its periphery below the keel is covered by 7 flattened and rounded cords separated by rather narrow interspaces. Cords on the shell base are broader, with interspaces exceeding the cord width. The cords are granular at intersections with growth lines. On the canal the cords become narrower, but the interspaces are still wide. The aperture is narrow, its width slowly decreases to the short and obliquely truncated canal. The inner lip is covered by thick white callus with longitudinal wrinkles near its edge. The columellar pleat is obsolete. The outer lip projects strongly forward below the sinus. The anal sinus is deep, U-shaped, slightly constricted at the entrance, with edges turned outside. The sinus is directed slightly adapically. Shell height 30.3 mm, body whorl height 18.6 mm, aperture height 14.7 mm, shell diameter 10.6 mm. The shell colour is brownish-grey, with brown spots between gemmules on the subsutural fold and, sometimes, peripheral keel, and two brown bands on the shell base, the upper being broader. The protoconch is dark-brown.

The paratypes are smaller (the largest is 28.5 x 9.7 mm). The diameter to height ratio varies from 0.34 to 0.40. Variability of paratypes mostly concerns the sculpture. The gemmules may slightly vary in prominence. Spiral cords may be somewhat narrower or broader and more or less granular. The fissure between the subsutural fold and the suture is sometimes rather wide. The columellar pleat is developed to various extent, but usually much stronger than in the holotype. The shell coloration is sometimes very faint, especially in alcohol-preserved specimens.
The operculum is narrowly leaf-shaped, with a terminal nucleus. The radula (paratype from sta. DW 410. shell height 21.5 mm) is typical of the subfamily Turrinae and consists of central and marginal teeth. The central tooth is weak but with a prominent spine-like central cusp. Marginal teeth are of wishbone type, robust, with short and broad accessory limb. The marginal tooth is 82 µm long. The new species is most similar to G jarrigei, but differs in having a multispiral protoconch and more prominent, usually granular spiral cords with wider interspaces, especially on the shell base and canal. The subsutural fold in G. neocaledonica is equal to, or even wider than the peripheral keel. Besides, these species seem to have somewhat different bathymetric ranges: G. neocaledonica was not found shallower than 375 m, whereas G. jarrigei—not deeper than 350 m. The two species co-occur in the area northward of New Cale¬donia (MUSORSTOM 4 stations).
G. neocaledonica much resembles the type-species of the genus, differing in having multi-spiral protoconch and almost twice larger shell at almost the same (8+ vs. 7+ in the type-species) number of teleoconch whorls which bear less prominent and more numerous gemmules on the peripheral keel.
The species also shows a striking similarity to some forms of Bathytoma Harris & Burrows, 1891, particularly to B. oldhami (Smith, 1899). The latter species mainly differs in having a shell about 1.5 times larger, with paucispiral protoconch, and possesses a true toxoglossate radula with long and curved hollow teeth (Sysoev, 1996).

Distribution. New Caledonia, Loyalty Islands, and southern New Hebrides Arc; alive in 420-550 m, shells recorded down to 710 m.