Pleurotoma

‖Pleu‐rot″o‐ma (?), n.; pl. L. Pleurotomæ (#), E. Pleurotomas (#). [NL., fr. Gr. � the side + τομή a cut.] (Zoöl.) Any marine gastropod belonging to Pleurotoma, and ether allied genera of the family Pleurotmidæ. The species are very numerous, especially in tropical seas. The outer lip has usually a posterior notch or slit.