Heliacus

Heliacus is a genus of gastropods belonging to the family Architectonicidae.

==General characteristics== (Original description in French) The operculum is corneous and conical, increasing in diameter from the apex to the base; its inner side is smooth with a central point; all the rest is composed of spirally coiled lamellae which decrease in diameter and are always fringed at their circumference. The shell is usually higher than the other sundials, with a narrower umbilicus.