Atys densus is a species of small tropical sea snail, a bubble snail, a marine opisthobranch gastropod mollusk in the family Haminoeidae, the haminoea bubble snails.
Description (Original description) The shell is small, oval, and thick, with a dirty white appearance. The surface is finely plicated and strongly striated in a transverse direction. Within the interstices, finer lines become visible when viewed under a lens. The aperture is narrow above but opens wide below. The outer lip is regularly arched; it is produced posteriorly, while anteriorly it is both twisted and produced, which allows it to partly cover the umbilicus. Tryon, George W., (George Washington), Pilsbry, Henry Augustus, Sharp, Benjamin (1893) - Manual of conchology, structural and systematic : with illustrations of the species; Ser.1,v.15 p. 272
Distribution This marine species is endemic to Australia and occurs in the Torres Strait and off Queensland.
References
Marshall, J.G. & Willan, R.C. 1999. Nudibranchs of Heron Island, Great Barrier Reef. Leiden : Backhuys 257 pp.