Systema naturæ - nature
   Universum - universe see [unranked] Mundus Plinius
     naturalia - natural bodies
       Regnum Animale nom. inval. - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Pisces nom. inval. - fishes see Class Pisces Linnaeus, 1758
           Order Chondropterygii nom. inval. see Order Nantes Linnaeus, 1758
             Genus Petromyzon nom. inval. see Genus Petromyzon Linnaeus, 1758
               Lampetra nom. inval.