Cleidodiscus is undoubtedly an artificial genus; however, if 

 one takes it in contemporary scope one sees that its basic hosts are 

 Centrarchidae. In addition to that, Cleidodiscus i s known in a small 

 number of species from Amiuridae and Pimelodidae (Siluridae) close to 

 each other, and also related to the cypriniformid Cyprinidae (but distant 

 from Siluroidae). All the last three families are very distant from the 

 first. Later we shall return to the questions concerning the genus Cleido- 

 discus and its occurrence (see page 476 ). 



Entobdella is encountered on three families of Pleuronectiformes 

 of the suborder Pleuronectoidei and is indicated for Trigonidae. In the 

 literature there is an indication of the finding of Entobdella on Scorpaenidae 

 which was not taken into consideration by us in Table 4 or in Table 12 be- 

 cause it is incorrect. The first and only indication concerning this is found 

 in the work of Heath (Heath, 1902) who writes that E. squamula is described 

 by him from Paralichthys californicus Ayres, and also on Sebastodes 



sp. sp. but considerably more rarely. We are convinced that Heath con- 

 fused two different species, and the one parasitizing Sebastodes sp. sp. 

 apparently belongs to the genus Benedenia . Since the finding of two species 

 of Entobdella on the skates does not arouse any doubt, [ E^ diadema Monticelli 

 was found by the author of the species on Trigon violacea Bonaparte near 

 Italy rarely but in a large number of individuals; _E. bumpsii Linton was 

 often found on Pastinachus centrourus (Mitchill) in Woods Hole near the Island 

 of Labrador--Price (Price, 1939)]. one must consider that Entodbella 

 parasitizes four families of groups of fishes unrelated and distant from 

 each other (pleuronectiformids and skates). 



The authenticity of the finding of representatives of the genus 

 Diplectanum on four families of fishes does not arouse any doubt. All these 

 families belong to the suborder Percoidei and have more or less consan- 

 guinous links with each other. As basic hosts for the genus, one should 

 consider two families, Serranidae and Sciaenidae>on which 10 of the 12 

 known species are encountered. In the literature there is another indication 

 which is not included in Table 12 about the finding of Diplectanum on 

 Labridae. This indication is erroneous because for Labridae, Diplectanum 

 pedatum (Wagener) Diesing is indicated as their parasite . This species 

 which is still practically undescribed (the species should be considered as 

 a nomen nudum), was discovered only by Wagener in 1857 and has never been 

 encountered by anyone else. Wagener indicates it as a parasite of Julis ? 

 (Wagener 1857a, page 99) and all the subsequent authors indicate Julis sp. 

 as a host without the question mark. One should suppose that there must 

 be here some sort of error in the determination of the fish; if it were not 

 so, D. pedatum would have been found in subsequent research. 



The genus Heteraxine is encountered on families pertaining to 

 Percoidei, i.e., families which are relatively close to each other. 



292 



