Natura - nature
   Mundus Plinius - physical world
     Naturalia - natural bodies
       Biota
         Domain Eukaryota Chatton, 1925 - eukaryotes
           Bikonta
             "photokaryotes"
               Chromalveolata
                 Alveolata Cavalier-Smith, 1991
                   Phylum Ciliophora (Doflein, 1901) Copeland, 1956 - ciliates
                     Subphylum Intramacronucleata Lynn, 1996
                       Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans
                         Subclass Peniculia Fauré-Fremiet, in Corliss, 1956
                           Order Urocentrida Jankowski, 1980
                             Family Parameciidae Dujardin, 1840
                               Genus Parameciumᵀ O.F. Müller, 1773
                                 Paramecium putrinum