“This species is only known from its type locality. It can easily be recognized by its columellaris hidden deep inside the aperture.” (Maassen, 2002)
Maassen (2002) original descriptions on Opisthostoma clerxi – “Shell sinistroid, white, slightly translucent; spire cylindrical, apex oblique. Whorls approximately 3½ (tuba not included), convex, with a hardly impressed suture, forming a cylindrical body which may be slightly oblique, to whorls distinctly oblique, hardly elevated. Constriction distinct and abrupt. Tuba consisting of approximately ½ whorl, touching the other whorls over its entire length and approximately circular in section. Shell with smooth apical whorls, the following ones with distinct radial ribs which are densely spaced on the body whorl (11 ribs/0.5 mm). Ribs crossed by a prominent spiral striation. Umbilicus open, very narrow. Aperture widely ovate to circular, hardly tilted with regard to the coiling axis of the shell; its upper margin not protruding beyond the level of the apex. Inner peristome moderately thickened and reflected; outer peristome moderately to distinctly flaring at the palatal side. Constriction with a long parietalis which continues into the tuba, a transversal palatalis and an obscure columellaris, deep inside the aperture.”
Opisthostoma clerxi – “Dimensions: H 1.0-1.1 mm; B 1.2-1.3 mm (including tuba), B 0.8-0.9 mm without tuba.” (Maassen, 2002)
Type locality – “Aceh Tengah; Laot Tawar, 7 km E of Takengon, south shore” leg. Maassen/1997 (Maassen, 2002)