Annelida Lamarck, 1809 - segmented worms
   Class Oligochaeta Grube, 1850 - oligochaetes see [unranked] oligochaetous Clitellata
     Order Tubificida
       Family Tubificidae Vejdovský, 1876 - sludge worms see Family Naididae Ehrenberg, 1828
         1 Genus [Aulodrilus] Bretscher, 1899
         2 Genus [Bothrioneurum] Michaelsen, 1900
         3 Genus [Branchiura] Beddard, 1892
         4 Genus [Limnodrilus] Claparède, 1862
         5 Genus [Tubifex] Lamarck, 1816