“The axis of the tuba has no fixed orientation with respect to the top whorls, which renders some variability to the type series. However, the mode of coiling is constant and we can assume the series does not consist of mutant individuals. It appears that O. gittenbergeri is endemic to a single limestone hill.” (Vermeulen & Clements, 2008)
Vermeulen & Clements (2008) original descriptions on Opisthostoma gittenbergeri – “Shell minute, thin, white, shiny. Apex not or hardly oblique. Whorls altogether 4⅔-5½, coiled at two different axes; top whorls 2⅓-2¾, discoid with the outer whorl distinctly raised above the level of the apex, passing into the body whorls without a completely detached whorl section; body whorls 2⅛-2⅝, coiled around an axis turned 45-80° with respect to the axis of the top whorls, together forming an approximately cylindrical body which widens slightly towards the apex; tuba 3/4-7/8 whorl, gradually turning downwards, the last ¼-⅜ whorl detached, coiling around an axis at 60-80° with respect to the axis of the body whorls. Constriction slight, with an inconspicuous transverse lamella in the basal edge. Spire with numerous straight (not sinuous), fine radial ribs, on the top whorls densely placed, 4-5 ribs/0.1 mm, somewhat more spaced elsewhere, with 3-4 and 2-4 ribs/0.1 mm on the body whorls and the tuba respectively. Spiral striation present, fine. Umbilicus open in the body whorls, up to 0.03 mm wide. Aperture more or less turned downwards, plane of aperture turned approx. 45-80° with respect to the axis of the body whorls, outline elliptic or rhombic with rounded edges and with the longest axis perpendicular with respect to the axis of the body whorls. Peristome double, outer peristome hardly flaring beyond the radial ribs next to it; inner peristome somewhat protruding from the outer, reflected, in particular on the side turned to the apex of the shell.”
Opisthostoma gittenbergeri – “Total length 1.4-1.5 mm; largest width (the diameter of the discoid top whorls) 0.55-0.6 mm; body whorl 0.4-0.5 mm long, 0.45-0.55 mm wide; tuba 0.5-0.6 mm long; aperture approx. 0.25-0.3 mm high and 0.35 mm wide.” (Vermeulen & Clements, 2008)
Type locality – “Peninsular Malaysia, Perak, Gunung Datok, 4° 36’ N, 101° 09’ E” leg. R. Clements (Vermeulen & Clements, 2008)