CHAPTER III 



SYSTEM OF MONOGENETIC TREMATODES 



Below is expressed the system of monogenetic trematodes 

 which was basically proposed by us as early as 1937 but supplemented 

 and changed in connection with subsequent works, ours as well as those 

 of numerous Soviet and foreign scholars. The following order of presen- 

 tation has been adopted: in the beginning a short description is given of 

 the systematic groupings under consideration, then considerations about 

 peculiarities of its evolution, questions linked with the history of its 

 study (to the extent that has a bearing on its foundation) and other 

 remarks of a general nature are cited. Thus the presentation of the 

 system resennbles rather' a critical analysis. With this one must take 

 into consideration that the questions concerning phylogeny are con- 

 sidered more completely in the next section and consequently are touched 

 only lightly here. 



The system is carried to subfamily; in a majority of cases 

 we shall be forced to dwell on separate genera and sometimes also on 

 intrageneric relations. This is explained by the fact that in some cases 

 the correlation between the families and the subfamilies amalgamated by 

 them are not clear without the analysis of their smaller taxonomic sub- 

 divisions. 



The divisions or subdivisions accepted by us: class (for its 

 characteristics and discussions see the work dedicated to the relations 

 between monogenetic trematodes and other groups --Bychowsky, 1937, 

 page 1379) subclass, order, suborder, family, subfannily, genus, species 

 (lower tcLxonomic units are not taken into consideration here because they 

 have been insufficiently studied). We have completely discarded as being 

 inconvenient the category of superfamily, which is accepted by English and 

 American authors and which practically in a majority of the cases for mono- 

 genetic trematodes corresponds to suborder. 



Class MONOGENOIDEA (Beneden) Bychowsky, 1937 



1 



If one should follow formally the rules of zoological nomenclature, the 

 indication in parentheses of Beneden as the author of the class is 

 erroneous. Actually, the class was established by us under this name 

 for the first tinae. However, we consider it obligatory to reproduce 

 the name of the researcher who first established the existence of the 

 group and such is undoubtedly van Beneden (van Beneden, 1858). Price 



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