Even though Megalocotyle is indicated for four families of fishes, 

 it is done so apparently erroneously. Thus, M. rhombi (Beneden and Hesse) 

 from the gills of Riiombus maximus L. should be attributed to the genus 

 Entobdella because the basic drawings of Van Beneden and Hesse (Van Beneden 

 and Hesse, 1863), the only ones who had this species in their hands, re- 

 semble the representatives of this genus much more than Megalocotyle. 

 This is all the more probable since Entobdella are characteristic for Pleuro- 

 nectiformes as we saw before. Thus, for the genus Megalocotyle one 

 should consider as hosts the representatives of three families of Perci- p. 259 



formes, which are, it is true, sufficiently distant from each other. 



The genus Octostoma is indicated from Bramidae apparently 

 erroneously because the species described by Parona and Perugia (Parona 

 and Perugia, 1896) under the name of Octobothrium bramae has never been 

 since encountered even once though it is attributed by contennporary authors 

 to the genus Octostoma (Kuhnia), but hardly correctly. The fact is, that 

 if one judges by the generally insufficient description and very schematic 

 drawings of Parona and Perugia, Octostoma bramae sharply differs from 

 the rest of the species of the genus by the number of hooks of the male sex 

 armature. As regards the finding of Octostoma on Sciaenidae we cannot 

 say anything definite because we did not have the corresponding work of 

 Yamaguti (Yamaguti, 1953). In any case, the genus is characteristic for 

 Scombroidei (according to Gregory), and it should be transferred into the 

 group parasitizing three fannilies. 



For Trochopus,the finding on Perciformes is characteristic. 

 Basically the species of this genus are encountered on Triglidae and 

 Scorpaenidae, which are close to them, and in addition in more rare cases 

 on two families very distant from each other and from Triglidae. 



Tw^o genera are indicated as occurring each on five families of 

 fishes. 



Of them, Pseudaxine is encountered on four families of the group 

 of Scombroidei, according to Gregory, and in addition to that, one of the 

 species is encountered on Sparidae, also related to Perciformes but some- 

 what further removed from the first four families. 



As regards the genus Haliotrema ,it is indicated basically on 

 Mullidae and on four more families of Perciformes; but of them, four 

 families are more or less close to each other (they are related to Per- 

 coidae) and one (Acanthuridae--H. xesuri, Yamaguti) is considerably re- 

 moved from the first. 



As a result of the analysis of 10 genera of Monogenoidea in- 

 dicated in Table 12 we see the following. 



293 



