1906). Finally Tristoma fuhrmanni Guiar (sic), although it was not de- 

 scribed in detail, was undoubtedly discovered on Raja sp. (see page 261 ), 



Likewise there are no doubts about the finding of Capsalidae on 

 Tstrodontiformes. Thus, five species of Capsala are found on Molidae. In 

 addition to that, there is an indication, although a rather dubious one and 

 not taken into consideration in the composition of Table 16, that T ristoma 

 was also found on the same family of fishes (see page 261 ). Likewise the 

 findings of Benedenia melleni on the four famiilies of Tetrodontiformes in 

 artificial conditions (see page 224) were not taken into consideration, nor the data about 

 finding Capsala on Diodontidae which do not deserve trust (see page 2bl ). 

 At any rate, both the occurrence of a number of species of Capsala in 

 nature and the infection in aquaria by Benedenia testify to the authenticity 

 of the Capsalidae parasitizing Tetrodontiformes. 



Three representatives of the genus Entobdella are authentical]y 

 known on Pleuronectiformes. The existing indications about tne finding of 

 Capsalidae of different genera on Pleuronectiformes are apparently erroneous 

 (see pages 258-261 )• For Acipenseriformes, the indications are known about 

 the presence of three species of Nit zschia and two of them apparently are 

 synonyms of the single authentic species--N^ sturionis (Abildgaard) (Brink- 

 maun, 195 2b; Shulnnan, 1954a ; in addition to that we have material on'N. 

 superta MacCallum" from North America, which shows that it is the same 

 N. sturionis). The indications of the finding of Benedenia on Mi^giliformes 

 are doubtful (see page 261 ). 



Thus, Capsalidae are known with certainty from five orders of 

 fishes quite distant from each other. Their basic number is encountered on 

 the most varied families of Perciformes and on orders of fishes which are 

 genetically connected with this order; namely- -Tetrodontiformes, and 

 Pleuronectiformes (see also page 316). Along with this, as is apparent from 

 wh^t has been said before, a small nunaber of species of Capsalidae are 

 undoubtedly found on fishes very distant from the Perciformes, that is on 

 sharks, skates, and (Acipenseriforrries ? , nobis) A'-ipc-seridae. 



Gyrodactylidae are authentically encountered on 10 orders of 

 fifshep; the majority of their specicb were in our hands and they were 

 eit.-ier collected personally by us or by our collaborators. Their classifi- 

 cation into orders and families of hosts practically coincides with the ones 

 for the genus Gyrodactylus (see page 316 ) with the addition of five more 

 parasices for Clupeifornaes (genus Gyrcdactyloides ) i^nd of one ( Paragyro - 

 dactylus) for Cypriniformes. Just as for the Gyrodactylus the parasitizing o. 277 

 on the most diversified families (orders) of fishes, the ones v/nich are related 

 to each other, just as the unrelated ones- -and periiaps there are considerably 

 niOre of the latter, is characteristic for this fainily. 



316 



