Plectostoma aethoderma (Vermeulen, 1994)
This species has a very distinctive shell compared to the rest of Bornean Species that ribs on the shell surface are very densely spaced.
Endemic to Mount Selabor and area nearby, Sarawak, Malaysia.
This species has a very distinctive shell compared to the rest of Bornean Species that ribs on the shell surface are very densely spaced.
Endemic to Mount Selabor and area nearby, Sarawak, Malaysia.
[Jaap Vermeulen, 1994]
Shell reddish-brown. Spire conical with convex sides. Apex (slightly) oblique. Whorls 6 1/8 - 6 7/8, convex; last whorl rounded. Constriction with a transverse palatalis. Tuba free from the spire, gradually narrowed towards the constriction, rounded below. Radial ribs very closely placed (12-20 ribs/0.5 mm on the penultimate whorl and half-way on the tuba), not sinuous. Spiral striation absent. Umbilicus almost closed or open, up to 0.10 mm across. Aperture hardly tilted with regard to he coiling axis, its upper margin widely below the level of the apex, elliptic. Peristome moderately spreading, simple or double, if double only inconspicuous so because the outer and the inner peristome are entirely fused, outer peristome hardly spreading beyond the inner, absent along the right side of the aperture. Spire: height 2.0-3.1 mm; width 1.5-1.7 mm; index 1.3-1.7. Total width 2.3-2.5 mm. Height aperture 0.8-0.9 mm; width 0.7-0.8 mm