The fourth species, Amphibdella maccallumi (Johnston and Tiegs), 

 is indicated from four species of fishes of which three are related to two 

 close genera of Torpedinidae and one (Squalus acanthias L. ) to Squalidae. 

 We have no doubt that the data about the last host are erroneous and con- 

 sequently A. maccallumi must be considered as encountered on two genera 

 of the same family of fishes. As a basis for this serves the fact that the 

 information about the finding of this species on Squalus acanthias is based 

 on the data of MacCallunn and in the work where he describes this species 

 for the first time, only one host--Tetranarce occidentalis (Storer) is in- 

 dicated (MacCallum, 1916a). As was mentioned earlier, the data of Mac- 

 Callum often do not deserve attention- -in his work the faults of labeling are 

 numerous and in this case this is very probable. 



The fifth species, Axine belones Ablldgaard, is only known with 

 certainty from one species of host.. Belone belone ( L. ), and is also in- 

 dicated by Palonnbi (Palombi, 1949) from the gilla of Tylosurus ( = Belone) 

 imperialis Raf. , Exocoetus rondeleti, Cm.^ and Hexocoetus heterurus L,. 

 It is possible that Palombi is right, but it is more probable that he was 

 dealing with several species of Axine, very close to each other, each 

 parasitizing a different species of host. Our research on the genus Axine 

 during the time of the 22nd cruise of the Expeditionary Vessel "Vityaz" in the Pacific 

 Ocean in 1955 serves as a basis for such an opinion. These 



researches showed that a number of close but independent species, each 

 of which is adapted to a very narrow circle of hosts and to only one species 

 of fishes, parasitize Exocoetidae and Belonidae. 



According to the literary data eight species of monogenetic 

 trematodes parasitize three species of fishes related to three genera of 

 different families but of one order: Ancyrocephalus manilensis Tubangui, 

 A. mogurndae (Yamaguti), Ancylodiscoides various Achmerov, Encotyllabe 

 spari Yamaguti, Heterocotyle minima (MacCallum), Thaumatocotyle 

 dasybatis (MacCallum), Squalonchocotyle abbreviata (Olsson) ,and Sq. grisea 

 Cerfontaine. 



According to the data of the author who described it, Ancyro- 

 cephalus manilensis is encountered on three families of the perciformid 

 group--Acanthuridae (typical host according to the author), Lutianidae, 

 and Serranidae. Unfortunately we did not see the works of Tubangui 

 (Tubangui, 1931) . Sproston (Sproston, 1946) indicates that in the aquarium 



_ 



We only had an extract from the text of the work describing the worm 

 itself. 



256 



