Thus, at the present time one can consider the system of „ 34Q 



Price as commonly accepted with separate changes in details put into 

 it by different authors after the period of the appearance of his series 

 of works. 



In 1937 a system different from the ones \diich have been 

 just expressed was proposed by us. It was based on the study of the 

 development of monogenetic trematodes. 



This system remained unknown outside for a number of 

 circumstances and is not even mentioned in the resumes indicated 

 above. As a result of the fact that it represents a basic sketch of the 

 system which is offered in the present work, we do not consider it 

 necessary to deal with it now; its separate peculiarities will be 

 discussed in appropriate places in the text that follows. 



Summarizing the short survey of the systems of the mono- 

 genetic trennatodes we see that they have changed very little in their 

 basic traits starting from the system of Monticelli until the present 

 time. The changes concern mainly details or are connected in a 

 majority of the cases with the appearance of new materials increasing 

 the number of known forms and correspondingly, groups. 



The system w^hich is proposed by us at the present time is 

 expanded in detail in the following chapter, it has the following general 

 form: 



Class --Monogenoidea (van Beneden)Bychowsky, 1937 

 Subclass --Polyonchoinea, Bychowsky, 1937 



A. Order --Dactylogyridea Bychowsky, 1937 



1. Suborder --Dacty logy rinea Bychowsky, 1937 



a. Family- -Dactylogyridae Bychowsky, 1933 



1. Subfamily- -Dacty logyrinae Bychowsky, 1933 

 Z. Subfamily- -Ancyrocephalinae Bychowsky, 1937 

 3. Subfamily --Linguadactylinae Bychowsky, 1957 



b. Family- -Diplectanidae Bychowsky, 1957 



1. Subfamily- -Diplectaninae Monticello, 1903 



2. Subfamily- -Rhamnocercinae Monaco, Wood 



and Mizelle, 1954 



c. Family- -Protogyrodactylidae Johnston and Tiegs, 1922 



d. Family--Calceostomatidae (Parona and Perugia, 1890) 



Price, 1937 



2. Suborder- -Monopisthocotylinea (Odhner, 1912) Bychowsky 1937 



a. Family --Monocotylidae Taschenberg, 1879 



401 



