Plectostoma panhai (Maassen, 2001)  

Apex. Shape: moderately convex.

Spire. Height: 2.1–2.2 mm. Width: 1.6–1.7 mm. Number of whorls: 4 1/2–4 5/8. Apical spire shape: depressed conical. Basal spire shape: ovoid. Whorl periphery: moderately convex. Umbilicus: open.

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

Tuba. Coiling direction: type 1 and aperture visible from back view. Tuba whorl length in proportion to spire last whorl: ca. 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: 8–9 ribs per mm. Rib intensity: thin. Shape: straight. Inclination: orthoclin.