Kingdom Protoctista Hogg, 1860
   Phylum Cryptophyta Caval.-Sm. (1986) - cryptomonads see Superclass Cryptomonada Cavalier-Smith, 2004
     Class Cryptophyceae F.E. Fritsch (1927)
       Order Cryptomonadales Pascher (1913)
         Genus Cyathomonas Fromentel (1874)
           Cyathomonas truncata (Fresenius, 1858) C. Fisch (1885) see Goniomonas truncata (G. Fresenius, 1858) F.R. von Stein (1878)