vor·ti·cel·la 
(vôr′tĭ-sĕlə)
(vôr′tĭ-sĕlə)n. pl. vor·ti·cel·lae (-sĕlē) or vor·ti·cel·las
Any of various ciliate protozoans of the genus Vorticella, having a bell-shaped body and living underwater on a slender stalk often attached to a plant or other object.
[New Latin Vorticella, genus name, from Latin vortex, vortic-, vortex; see VORTEX.]
vorticella