Murices

from The Collaborative International Dictionary of English v.0.48

Rhachiglossa \Rhach`i*glos"sa\, n. pl. [NL. See {Rhachis}, and
   {Glossa}.] (Zool.)
   A division of marine gastropods having a retractile proboscis
   and three longitudinal rows of teeth on the radula. It
   includes many of the large ornamental shells, as the
   {miters}, {murices}, {olives}, {purpuras}, {volutes}, and
   {whelks}. See Illust. in the Appendix.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Murex \Mu"rex\, prop. n.; pl. {Murices}. [L., the purple fish.]
   (Zool.)
   A genus of marine gastropods, having rough, and frequently
   spinose, shells, which are often highly colored inside; the
   rock shells. They abound in tropical seas.
   [1913 Webster]