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)
         Family Hemiselmidaceae Butcher (1967)
           1 Genus Hemiselmis M. Parke (1949)
           1.0.1 Genus Planonephros T. Christensen (1978)
           1.0.2 Genus Nephroselmis sensu Pascher (1913) see Genus Planonephros T. Christensen (1978)
           1.0.3 Genus Sennia sensu Skuja (1948) see Genus Planonephros T. Christensen (1978)