Two families of monogenetic trematodes are indicated as 

 occurring on three orders of fishes. The first--Acanthocotylidae--is 

 discovered on belachiiformes (13 species of one genus of worms on one 

 family of Rajidae), Perciformes (1 species) and Anguilliformes (1 species). 

 The indication of the finding among the Perciformes pertains to Lophocotyle 

 cyclophora Braun for which a number of authors indicates Notothenia sp. 

 as host (see Johnston and Tiegs, 1922; Sproston 1946, and others). If we 

 turn to the original description of Braun (Braun, 1896) we will see that he 

 writes somewhat differently, thus, in two places in his work he indicates 

 "the collection of Michaelson" (Hamberger Magalhaensische Sammelreise, 

 No. 176, Navarin, Puerto Toro), There are two samples of monogenetic 

 trematodes labelled thus: "probably from the skin of Notothenia 20, XII. 92. " 

 Thus, we don't have sufficiently serious basis to consider the finding of 

 li. cyclophora on the Perciformes and are inclined to think, rather, that it p. 275 



is not so. The indication of the Anguilliformes refers to Enoplocotyle 

 minima Ta.gliani, discovered on the skin of Muraena helena (L. ). We have 

 no basis for'doubt in this case, but, nevertheless, this finding remains not quite 

 clear. As a matter of fact, other questions connected with this species will 

 be indicated in detail later (see page 385 ). Taking into consideration what 

 has been said, we can consider that Acanthocotylidae are apparently 

 encountered not on three orders of fishes, but on two and on one of them as 

 a normal (regular, lawful, nobis) exception. 



The second, family indicated for three orders of hosts is 

 Diplectanidae. It is known from a number of families of perciformids. In 

 addition to that.Yamaguti described two genera from Mugiliformes 

 ( Pseudolamellodiscus ) and from Clupeiformes (Diplectanocotyle ) (Yamaguti, 

 1953). As was already indicated, we did not have the given work of Yamaguti 

 and because of that we cannot say anything about both genera. We shall note, 

 however, that we have already spoken about the connection between Mugili- 

 formes and Perciformes, and Clupeiformes are far removed from the latter 

 and from the Mugiliformes. Diplectanidae are discovered on the Perci- 

 formes, on Serranidae (14 species of worms), Sciaenidae (8-7 species), 

 Sparidae (7-6 species), Lethrinidae (2 species), Nemipteridae (2 species), 

 Liognathidae (1 species), and Girellidae (1 species). All these families 

 are related to the superfamily Percoidae, and undoubtedly have sufficiently 

 close genetic links. 



Microcotylidae parasitizes four orders--Perciformes, Beloni- 

 formes, Mugiliformes and Polynemiformes. Microcotylidae are encountered 

 very widely on the Perciformes. Thus, they are discovered on 32 families 

 relating to nine suborders: Percoidei, Blennoidei, Siganoidei. Acanthuroidei, 

 Scombroidei, Stromateoidei, Thunnoidei, Gobioidei, and Cottoidei. So far 

 Microcotylidae are not known from Ophioidei, Ammodytoidei, Trichiuroidei, 

 Tetragonuroidei, Callionymoidei, Anabantoidei, Luciocephaloidei, and 

 Kurtoidei (so far monogenetic trematodes have been studied only on the 

 first three suborders), but there is no doubt that they will be discovered 



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