Morphology:
Description by Vermeulen (1994)
"As the type subspecies, but constriction usually with a parietalis which continues up to or slightly beyond the sharp inner curve of the tuba, and which is low and inconspicuous, (or ven absent) at the constriction, but high and distinct halfway the tuba, without an angularis. Spire with 6 radial ribs/0./5 mm on the penultimate whorl; tuba with 5-20 ribs/0.5 mm half-way. umbilicus closed, or open, up to 0.05 mm side. Spire: height 0.7-0.8 mm; width 0.7 mm; index 1.0-1.2. Total width 1.0-1.1 mm. Height and width aperture 0.30 mm."
Taxonomic name: