Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Annelida Lamarck, 1809 - segmented worms
     Class Oligochaeta Grube, 1850 - oligochaetes see [unranked] oligochaetous Clitellata
       Order Haplotaxida
         1 Family Tubificidae Vejdovský, 1876 - sludge worms see Family Naididae Ehrenberg, 1828
         2 Family Naididae Ehrenberg, 1828 - naidids
         3 Family Lumbricidae Rafinesque-Schmaltz, 1815 - earthworms