Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Polyplacophora Blainville, 1816 [monotypic] - chitons
     Subclass Polyplacophora Gray, 1821 [monotypic] see Class Polyplacophora Blainville, 1816
       Order Lepidopleurida Thiele, 1910
         Suborder Chitonina Thiele, 1909
           Family Ischnochitonidae Dall, 1889
             Subfamily Ischnochitoninae Dall, 1889 see Family Ischnochitonidae Dall, 1889
               Genus Ischnochiton Gray, 1847
                 Subgenus Stenosemus von Middendorff, 1847 see Genus Stenosemus von Middendorff, 1848