Source : Webster's Revised Unabridged Dictionary (1913)

Pleurotoma \Pleu*rot"o*ma\, n.; pl. L. {Pleurotom[ae]}, E.
   {Pleurotomas}. [NL., fr. Gr. ? the side + tomh` a cut.]
   (Zo["o]l.)
   Any marine gastropod belonging to {Pleurotoma}, and ether
   allied genera of the family {Pleurotmid[ae]}. The species are
   very numerous, especially in tropical seas. The outer lip has
   usually a posterior notch or slit.