Plectostoma charasense (Tomlin, 1948)  

Apex. Shape: distinctly convex.

Spire. Height: 1.9–2.0 mm. Width: 1.3–1.4 mm. Number of whorls: 4 1/8. Apical spire shape: oblong conical. Basal spire shape: conical. Whorl periphery: distinctly convex. Umbilicus: open.

Constriction. Parietal teeth: two. Basal teeth: two.

Tuba. Coiling direction: type 2 and aperture visible from right lateral view. Tuba whorl length in proportion to spire last whorl: ca. 7/8. Proportion of tuba that attaches to spire: less than 1/2.

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: absent. Thin lines: present.

Radial ribs. Rib density: 4 ribs per mm. Rib intensity: thick. Shape: slightly curved to single-humped. Inclination: moderately prosoclin.