Some controversial problems in classification of Monogeneans.

The paper contains the main objections of foreign specialists (Llewellyn and others) to Bykhovsky's system of monogeneans. Llwellyn's interpretation of anchors and marginal hooks which is the basis of his phylogenetic scheme is proved to be erroneous by a number of data on morphology of chitinoid formations and on their mutual position. Thus the phylogenetic scheme loses its integrity and cannot be accepted. The system of Bykhovsky remains now the most natural. Some additions or changes do not break its principles.