- Description
- The Helmet Shells are heavily constructed, large or medium size shells with a rather short spire and a well-developed final whorl. The body whorl is voluminous, and often ornamented with knobs and varices (lengthwise ribs). The callus is well developed and extends over the entire ventral surface. Coarse teeth on the inner side of the lip and several prominent columellar folds are common, but not invariable.
- Defining characteristics are: outer lip thickened and recurved on the dorsal surface to form a prominent helmet-like rim; and, a short syphonal canal bent backwards and opening toward the dorsal surface. The Family contains eighty or more living species that live in warm waters around the world.
- This snail has a dramatic way of feeding on sea urchins. It creeps up slowly, raises its heavy shell quite high, then abruptly drops the shell in such a way that the urchin is completely engulfed. Since urchin spines contain a poison, the helmet snail releases a paralytic enzyme from its salivary gland, then it secretes sulfuric acid sufficiently strong to dissolve the sea urchin shell in about 10 minutes before consuming its meal.
- Classification:
- Class: Gastropoda
- Clade: Littorinimorpha
- Superfamily: Tonnoidea
- Family: Cassidae
- Major Genera
- Genus: Casmaria
- Genus: Cassis
- Genus: Cypraecassis
- Genus: Galeodea
- Genus: Galeoocorys
- Genus: Morum
- Genus: Oocorys
- Genus: Phalium
- Genus: Sconsia
Phalium glaucum (Linnaeus, 1758)
Gray Bonnet
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