Apex. Shape: slightly or moderately convex.
Spire. Height: 1.3–3.0 mm. Width: 1.2–1.4 mm. Number of whorls: 3 1/2–4 1/2. Apical spire shape: depressed conical. Basal spire shape: ovoid. Whorl periphery: moderately or distinctly convex. Umbilicus: closed by tuba (common) or partially open (rare).
Constriction. Parietal teeth: none. Basal teeth: none.
Tuba. Coiling direction: type 3 and aperture visible from left lateral view. Tuba whorl length in proportion to spire last whorl: ca. 1/2–3/4 Proportion of tuba that attaches to spire: whole.
Aperture and peristome. Peristome: double peristomes. Outer peristome shape: same as inner peristome and uniformly projected all around, except the posterior part.
Spiral lines. Thick lines: present. Thin lines: present.
Radial ribs. Rib density: 6–8 ribs per mm. Rib intensity: thin. Shape: straight. Inclination: moderately prosoclin.
to be added
Holotype: ZMA 135994(1) (Seen). Paratype: ZMA 135993(>50) (Seen).
The species is well-characterised, although it displays considerable variability in the shell shape (Appendix 6).
Type locality. Gua Musang (4°52'59"N, 101°58'12"E).
Distribution range. This species mainly occurs in the limestome hills that are located between Gua Musang and as far as 30 km radius of Gua Musang. One populations exists at a limestone hill that is located about 90 km north of Gua Musang (Figure 18A).