Shell · Genus
Cassis
Helmet shells
Helmet shells (Cassis) are large, heavy snails with a thick flaring lip and a shield-like inner surface, the classic cameo-carving shell (Cassis madagascariensis, the queen helmet). Whole shells are sold as décor and were once common souvenirs; large undamaged examples are now less common as harvests are restricted. Cameos carved from helmet shell show a white layer over brown.
| Habitat | Sandy bottoms in shallow tropical water, feeding on sea urchins |
|---|---|
| Regions | Caribbean, Indo-Pacific, Mediterranean, Australia |
| Family | Cassidae |
| Authority (WoRMS) | Scopoli, 1777· WoRMS / MolluscaBase |
| Status (WoRMS) | accepted· WoRMS / MolluscaBase |
| Classification (WoRMS) | Animalia › Mollusca › Gastropoda › Littorinimorpha › Cassidae· WoRMS / MolluscaBase |
CITES and protection
Not CITES-listed, but Cassis cornuta and Cassis madagascariensis are protected in some countries (Australia, several Caribbean states) and harvest for cameo carving is regulated in Italy.
Care (Byne's disease)
Large helmet shells are thick and stable; the glossy lip can be dulled by Byne's.
Elsewhere
- WoRMS AphiaID: 206265
- Wikidata: Q846028
- WoRMS / MolluscaBase record
- Wikipedia: Cassis
- CITES Appendices
Cite this article
Stratum Strata. "Cassis" (Shell family). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/shells/cassis. Accessed 2026-09-21.
@misc{stratum-cassis,
title = {Cassis},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/shells/cassis}},
year = {2026},
note = {Shell family article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, worms, wikidata, commons. Accessed 2026-09-21.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.