Class Hirudinea Lamarck, 1818 - leeches see Subclass Hirudinida
   Subclass Euhirudinea Lukin, 1956 - true leeches see Subclass Hirudinida
     1 Order Rhynchobdellida Blanchard, 1894
     2 Order Arhynchobdellida Blanchard, 1894