The common name "murex" is also used for a large number of species in the family Muricidae, most of which in the past were originally given the Latin generic name Murex, but most of which have now been grouped in other newer genera.
The word murex was used by Aristotle in reference to these kinds of snails, thus Murex is arguably one of the oldest classical shell names still in use by the scientific community.
This genus includes many showy members, their elongate shells highly sculptured with spines or fronds. The inner surfaces of their ornate shells are often brightly colored.
Costly and labor-intensive dyes Tyrian purple (or royal purple) and Tekhelet were historically made by the ancient Phoenicians using mucus from the hypobranchial gland of two species commonly referred to as "murex", Murex brandaris and Murex trunculus, which are the older names for Haustellum brandaris and the Hexaplex trunculus.
This dye was used in royal robes, other kinds of special ceremonial or ritual garments, or garments indicating high rank. It is theorized that the dye was the same dye as that which featured prominently in the ancient Temple in Jerusalem, the clothing of the High Priest (or Kohen Gadol) officiating there; it is sometimes still used by Jews today in the ritual fringes (tzitzit) on four-cornered garments. A consensus has yet to be achieved regarding the Biblical source of the "blue" dye.