Shell trivaricate, small to moderately large (50—150 mm), with or without short spines. Distal tip of siphonal canal slightly deflected in some species, otherwise similar to Murex. Axial ornamentation on early teleoconch whorls of (usually) 12 rounded ribs, of which every fourth strengthens into varix, leaving three intervarical nodes initially. Labral tooth never present. Inner lip often expanded into moderate to very large inductura, frequently bearing rugae or denticles. Operculum with subterminal to subcentral nucleus, growth lines simple to sublamcllate. Radula as in Murex but with bases of marginal teeth less expanded in most species so they do not overlap. Ejaculatory duct not embedded in body wall, non-muscular, sometimes open or partly open. Radular sac markedly shorter than buccal mass. Accessory salivary glands very small, possibly absent in some species.