Class Hirudinea Lamarck, 1818 - leeches see Subclass Hirudinida
   Subclass Euhirudinea Lukin, 1956 - true leeches see Subclass Hirudinida
     Order Rhynchobdellida Blanchard, 1894
       1 Family Glossiphoniidae Vaillant, 1890
       2 Family Piscicolidae Johnston, 1865
       3 Family Ozobranchidae Pinto, 1921