Alcyna acia, common name the tread top shell, is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Trochidae, the top snails.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0