Animalcule is an older term for a microscopic animal or protozoan. Some better-known animalcules include:

  • Rotifers, called wheel animalcules
  • Paramecium, called slipper animalcules
  • Stentor, called trumpet animalcules
  • Vorticella, and other peritrichs, called bell animalcules
  • Actinophrys, and other heliozoa, called sun animalcules
  • Amoeba, called proteus animalcules