Fossarina patula

Fossarina patula is a species of very small sea snail, a marine gastropod mollusc or micromollusk in the family Trochidae, the top snails.

Description
The shell grows to a length of 6 mm. The shell is widely umbilicated, with alternate larger and smaller tuberculated spiral ribs. The ribs are simple on the base. The umbilicus is acutely carinate-margined. The shell is whitish, sparsely maculated with dark brown. The three whorls are convex. The outer lip is ascending posteriorly.

Distribution
This marine species is endemic to Australia and occurs off New South Wales, Tasmania and Victoria