the pipe. At the same time with this, five of them are encountered on 

 Cyprinodontidae (3 species), Poecoelidae (1 species), Anoiuridae (1 

 species), i.e. , on fishes far removed from Perciformes which are 

 parasitized by the typical representatives of Urocleidus. The remaining 

 2 species are encountered on Percidae but also sharply differ from 

 Urocleidus s. lat. in our understanding. Hence, it is understandable 

 that there is nothing surprising in this if we will remember that many 

 representatives of the genus Ancyrocephalus and other Ancyrocephalinae 

 are encountered on Percidae. It is interesting that American authors 

 became completely confused in the understanding of the scope of the 

 genus Urocleidus. Thus, the type of the genus U. aculeatus Van Cleave and 

 Mueller w^as taken out of this genus relatively recently and in our opinion 

 quite correctly. At the same time, no synoymic conclusions were made 

 from this (see Mizelle and Regensberg, 1945). 



All in all one can state with certainty that in its contemporary p. 351 

 scope the genus Urocleidus is artificial. Even if all the three nnentioned 

 groups which pertain to groups which we believe should be considered as 

 natural genera are united into one genus, then the 7 remaining species 

 do not in any way belong to Urocleidus (s. lat. ) and should be referred 

 to several of the existing genera of Ancyrocephalinae (apparently part to 

 Ancyrocephalus and part to Cleidodiscus ). 



It is clear from what has been said that one can speak only 

 with great reservations about the natural interrelations of the separate 

 genera of Ancyrocephalinae. Nevertheless , during the analysis separate, 

 quite distinct groups are noted. Thus, undoubtedly the genera Ancylo - 

 discoides , Bychowskyella , and Hamatopeduncularia , the representatives 

 of which are characterized by morphological similarity and which 

 parasitize hosts pertaining only to Siluridae and the closely related 

 Bagridae and Ariidae, are close to each other. In spite of the great 

 peculiarity of its attaching apparatus the genus Anchoradiscus (Fig. 267) 

 undoubtedly descends from a common root with Actinocleidus ; both 

 genera parasitize Centrarchidae and are encountered only in America. 

 We have already spoken about the correlations between Ancyrocephalus 

 and Haliotrema s. str . One must only note that in its contemporary 

 scope the genus Ancyrocephalus also deniands re -examination because in 

 addition to the typical forms in it are included species which do not 

 actually have any relation with it, as for instance A. cruciatus (Wedl) 

 which undoubtedly belongs in Che group of species close to the genus 

 Cleidodiscus, or A. atherinae Price which sharply differs by the 

 character of the edge hooks and which appears to be a representative 

 of a special genus. 



416 



