Small, rounded lens-shaped to depressed cone-shaped shell with moderately wide to wide umbilicus and shallow sutures; upper-side sculpture of 4 ribs (2 central ones weaker) with more or less flattened nodules; rounded double keel formed by 2 ribs, with lower one somewhat weaker; fine additional ribs between ribs at periphery; basal sculpture of 5 regular spiral ribs, with innermost (surrounding umbilicus) narrower then the one before it; outer base area with additional fine spiral threads; umbilical side of columellar wall usually with 1 projection. Fawn with regular darker flames; subsutural rib and umbilical crenae lighter and spire darker. Protoconch diameter 0.82-0.98 mm, distinctly heterostrophic, without anal keel.
Teleoconch: small, diameter of specimens in collections usually 5-8.9 at 3 to 4 1/8 whorls. Shape: juveniles very rounded, lens-shaped; later depressed cone-shaped with distinctly convex whorls; umbilicus moderately wide to wide (UD 18-30% of SD); suture shallow. Sculpture: Upper side: SSR and UPR usually markedly stronger than the 2 MR between them, UMR usually somewhat wider than LMR; between LMR and UPR on later whorls always 1 additional rib; Periphery: rounded double keel formed by LPR and somewhat weaker IPR, on later whorls always with 1 finer additional rib between the two; upper point of whorl attachment on LPR; Base: usually 5 regular spiral ribs, somewhat increasing in width towards umbilicus; PUR usually distinctly wider than UC; UC with 15-26 nodules on body whorl; outer base area usually with additional fine spiral threads; umbilical side of columellar wall convex, usually with 1 spiral projection. Coloration: fawn, with SSR and UC lighter and spire darker; ± regular darker flames on whole shell (2-3 nodules wide on peripheral ribs). - Protoconch: small to medium-sized (0.82-0.98, x = 0.89), multispiral, distinctly heterostrophic, without anal keel; tan. - Operculum: as described for subgenus. - Radula and Anatomy: not known.

Heliacus implexus is similar, but has larger shells (8-10 at 3-4 whorls) and 1 distinct spiral rib in the umbilicus. Heliacus geminus differs by having fewer umbilical crenae, and by much more prominent peripheral ribs, giving the shell an angular appearance.

Geographical distribution: Known from Japan, eastern Australia and Norfolk Island.
Habitat: Sublittoral; most records from between 35m and 140m.