The Collaborative International Dictionary
Bell animalcule
Bell animalcule \Bell" an`i*mal"cule\ (Zo["o]l.) An infusorian of the family Vorticellid[ae], common in fresh-water ponds.
Wiktionary
bell animalcule
n. (context zoology English) An protozoan of the family (taxlink Vorticellidae family noshow=1), common in freshwater ponds.