Typically 2.0 x 1.1 mm. 6 - 9 very prominent apertural teeth almost filling the aperture; sculpture smooth with irregular growth lines.
Rather dry places. Most typically on or at the base of ivy-covered stone walls, usually shaded by trees but also recorded from rocks, ground litter in open woodland, hedge banks, natural cliffs and occasionally in fixed sand dunes.
Widespread but local.Widespread but local, reaching the Artic circle in Scandinavia.