Dactylogyrus inversus is described from Lateolabrax 

 japonicus (Cuv. and Val. ) (Serranidae) and is often found on it, besides 

 it is also indicated from the gills of the scombrid, Pneumatophorous 

 japonicus Houtt. (Ishii and Sawada, 1938a). The latter seems unjusti- 

 fiable to us and demands careful verification. Even though they are related 

 to one order Serranidae and Scombridae are nevertheless very distant 

 from each other. 



Diplectanum aequans is described from Morone labrax (L. ) 

 and was encountered on it by a number of authors and is indicated from 

 Umbrina cirrhosa (L. ), the latter indication is made by Sonsino (Sonsino, 

 1890) and is undoubtedly erroneous because it refers to another species 

 of Diplectanum as we succeeded in elucidating in our nnaterial (Bychowsky, 

 1957). Thus, up to this time, D. aequans has been encountered only on 

 one species of host. 



Similarly, Encotyllabe pagrosomi must be considered as 

 occurring only on one species of fish--Pagrosomus auratus (Houtt. ), be- 

 cause the indication of the finding of this species on Caulolatilus sp. 

 actually refers to another species. Thus, Meserve (Meserve, 1938) des- 

 cribed one sample of Encotyllabe under the nanne of E. pagrosonni and in 

 the text indicated that this deter nnination was provisional. Comparison 

 between his data and the data of Price (Price, 1937b), although Meserve 

 refers to the latter, indicates that the individual from Caulolatilus sp. 

 must be considered as undetermined pending further findings, and at any 

 rate it is not E. pagrosomi. 



Gyrodactylus medius is described by Kathariner (Kathariner, 

 1894) from the gills of Cyprinus carpio (L. ) (Cyprinidae) and from Mis- 

 gurnus fossilis (L. ) (Cobitidae) and then a mass of different Gyrodactylus 

 from various fishes, but mainly Cyprinidae was indicated under this 



1 



As is indicated in the text, G. nnedius is placed in the group under 

 study on the basis of the fact that it was described from two species of 

 fishes. It is understood that this is a provisional arrangement. 



name. There is no doubt that present knowledge gives basis with complete 

 certainty to consider that this parasite is encountered only on C. carpio 

 and that even Kathariner who described it was mistaken in thinking that 

 G. medius was also encountered on M. fossilis , Thus this species must 



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