Class Cryptophyceae Pascher ex Schoenichen (1925) see Class Cryptophyceae F.E. Fritsch (1927)
   Order Cryptomonadales Pascher (1913)
     Family Hemiselmidaceae Butcher (1967)
       Genus Hemiselmis M. Parke (1949)
         1 Subgenus Hemiselmis subg. Hemiselmis (M. Parke, 1949) Butcher (1967)
         2 Subgenus Hemiselmis subg. Plagiomonas Butcher (1967)