Annelida Lamarck, 1809 - segmented worms
   Class Oligochaeta Grube, 1850 - oligochaetes see [unranked] oligochaetous Clitellata
     Order Opisthopora
       Family Octochaetidae Michaelsen, 1900
         1 Genus [Dichogaster] Beddard, 1888
         2 Genus [Eudichogaster] Michaelsen, 1902
         3 Genus [Eutyphoeus] Michaelsen, 1900
         4 Genus [Lennogaster] Gates, 1939
         5 Genus [Octochaetoides] Michaelsen, 1920
         6 Genus [Octochaetus] Beddard, 1893
         7 Genus [Pellogaster] Gates, 1939