Kingdom Protista (Haeckel, 1866) - protists Phylum Ciliophora Doflein, 1901 - ciliates Class Kinetofragminophorea - kinetofragminophoreans see Phylum Ciliophora Doflein, 1901 Subclass Gymnostomatia - gymnostome ciliates see Phylum Ciliophora Doflein, 1901 Genus Didinium Stein, 1859 Didinium nasutum (O.F. Müller, 1773) Stein, 1859