Taxon classification Animalia Mesogastropoda Diplommatinidae

Moussonia longipalatalis sp. n. Figs 59-60

Type material.

Holotype MNHN IM-2000-27441, paratypes MNHN/630 IM-2000-27442, NMBE 516852/50. Type locality: Lau Islands, Navutu-i-Loma (= Nasau), forest on limestone, 5-30 m, -18.9659 -178.4798, leg. Bouchet, 11.03.1999.

Etymology.

Latin adjective longus, -a, -um = long, and noun palatalis for the palatal fold; used as a noun in apposition.

Diagnosis.

Shell dextral, very small, translucent light yellowish-brownish, bluntly keeled whorls, reduced sculpture, palatalis a very long lamella.

Description.

Shell dextral, very small, last whorl not constricted, translucent light yellowish-brownish; protoconch of 2 whorls, granulated; teleoconch of> 7 bluntly keeled whorls, sculpture of faint periostracal threads; suture very deep; last whorl not ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a weak labial callus, columellar side with a strong columellaris; umbilicus closed; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis long, outer parietalis spatulate; palatalis a very long lamella, situated on the left side above the aperture (can be seen from the outside as a reflecting callus).

Measurements.

Holotype (Fig. 59): H = 2.13; D = 1.09; PH = 0.65; PD = 0.69; W = 7.5.

Distribution

(Fig. 171). Only known from the type locality.

Remarks.

Although very similar to Moussonia fuscula, Moussonia longipalatalis sp. n. is treated here as a different species because the latter has a smaller shell, bluntly keeled whorls, and a long and very readily visible palatalis, which is only a short knob-like callus in Moussonia fuscula .