Diplommatina bidentata Vermeulen, Liew & Schilthuizen

Vermeulen, Jaap J., Liew, Thor-Seng & Schilthuizen, Menno, 2015, Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species, ZooKeys 531, pp. 1-139 : 20

Taxon classification Animalia Architaenioglossa Diplommatinidae

Diplommatina bidentata Vermeulen, Liew & Schilthuizen sp. n. Figure 17

Holotype. Malaysia, Sabah, Tawau Province , Batu Baturong c. 50 km W.S.W. of Lahad Datu (leg. J.J. Vermeulen & H. Duistermaat, RMNH.5003954 ).

Examined material from Sabah.

Tawau Province. Batu Baturong c. 50 km W.S.W. of Lahad Datu (leg. J.J. Vermeulen & H. Duistermaat, V 7581).

Description.

Shell dextral, conical, with the last whorl or the last two whorls widest; sides flat or slightly convex. Suture impressed. Constriction level with the parietal side of the peristome, with 1 parietalis which continues as a lamella down to the aperture, 1 longitudinal palatalis slightly to the left of the parietal peristome, 1 transversal palatalis, 1 columellaris which continues as a lamella down to the aperture. Tuba 7/8 whorl. Sculpture. Radial ribs straight, distinct, rather low, rather wide, rather densely placed (7-11 ribs/0.5 mm on the penultimate whorl). Spiral striation present, inconspious, fine and dense. Aperture hardly tilted with regard to the coiling axis; columellaris large, slightly downwards directed; the distal end of the parietalis visible on the parietal side as a tooth. Peristome double, expanding; palatal side only slightly sinuous, without edge; basal side without edge; basal edge not sinuous; outer peristome not or hardly expanding beyond the inner; inner peristome with a palatal lip, free and erect on the columellar side, expanding on the parietal side. Umbilicus open, narrow. Dimensions. Height 1.9-2.3 mm; width 1.00-1.25 mm; umbilicus 0.05-0.20 mm wide; number of whorls 6-6 3/4; height and width aperture 0.25-0.30 mm.

Habitat in Sabah and distribution.

(Disturbed) primary forest on limestone bedrock, at c. 100 m alt. Sabah: East coast, Baturong Hill only. Endemic to Sabah.

Cross diagnosis.

Uniquely identified by the parietal lamella, which runs over the full length of the tuba and which is visible as a pearietal tooth deep in the aperture.

In Vermeulen (1993) it keys out next to Diplommatina cacuminulus Vermeulen, 1993. Yet it seems most similar to Diplommatina toretos Vermeulen, 1993; it shares the open umbilicus with this species.

Etymology.

The name refers to the two teeth in the aperture [bidentata (L.) = with two teeth].