Found south of Auckland to north Canterbury with an outlier near Dunedin.
New Zealand Threat Classification System
Not threatened
Bio Status
Indigenous (Endemic)
Description
Shell small, about 4.4mm at 5 whorls, discoidal or biconcave, axially ribbed, umbilicated, translucent pale buff with brown axial colour streaks. Spire height varies from sunken to weakly elevated. Umbilicus wide, about one third of max. shell diameter. Protoconch of 1.4 whorls, axially ribbed and spirally lirate. Axial ribs more widely spaced on first three quarters of embryonic shell; spiral lirae low, widely spaced at first then becoming more regular and closely spaced. Teleoconch whorls convex, increasing regularly and moderate fast. Sculpture consisting of primary axial ribs of alternating height (sometimes less conspicuous) crested by long periostracal lamella and interstitial secondary axials of regular height, ornamented with apical periostracal lamella. Axials protractive, weakly sigmoidal on periphery and base Spiral lirae traverse primary and seconday axials, forming minute beads where secondary axials and spiral lirae intersect. Aperture obliquely round, outer lip retracted at suture leaving a distinct sinus. Columella short, oblique and very slightly reflexed.
Habitat
Predominantly a litter-dweller but also found under rotting logs & ferns, limestone boulders, among talus in cave entrances and on limestone ledges; lives in shrublands and forests from sealevel to around 1000m.
