Murex

Murex is a genus of medium to large sized predatory tropical sea snails. These are carnivorous marine gastropod molluscs in the family Muricidae, commonly called "murexes" or "rock snails". The common name murex is still used for many species in the family Muricidae which were originally given the Latin generic name Murex, but have more recently been regrouped into newer genera. Murex was used in antiquity to describe spiny sea snails, especially those associated with the production of purple dye. Murex is one of the oldest classical seashell names still used by the scientific community.

Source: Wikipedia