Plectostoma mengaburensis Liew, Vermeulen, Marzuki & Schilthuizen, 2014  

Apex. Shape: moderately convex.

Spire. Height: 1.9–2.2 mm. Width: 1.4–1.6 mm. Number of whorls: 3 7/8–4 1/2. Apical spire shape: depressed conical. Basal spire shape: ovoid. Whorl periphery: distinctly convex. Umbilicus: open or half of the umbilicus closed by tuba.

Constriction. Parietal teeth: none. Basal teeth: none.

Tuba. Coiling direction: type 1 and aperture visible from back view. Tuba whorl length in proportion to spire last whorl: ca. 5/8. 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: 7 ribs per mm. Rib intensity: thin. Shape: straight. Inclination: orthoclin.