The subfamily is very specialized and lives basically on the 

 skin of fast-moving fishes (an exception--several species from Mola mola 

 L.. ) in connection with which the attaching organs are very powerfully 

 developed. In this connection the middle hooks apparently lose their 

 function very early during the time of postembryonic development and 

 quickly degenerate. Thus, among a number of species, one observes a 

 gradual disappearance of these formations and it is even accompanied by 

 their disintegration. We observe this phenomenon in Capsala pelamydis 

 (Taschenberg) from the material from the Black Sea which was transferred 

 to our. laboratory by A. V. Rechetnikova. This circumstance is very 

 innportant because it shows one of the means of disappearance of chitinous 

 attaching organs which are losing their function. It is possible that 

 among aberrant groups of monogenetic trematodes this process proceeded in 

 a similar fashion (see page 347 ). Unfortunately, the development of 

 Capsalinae was not studied and at the present time we cannot say anything 

 about the initial number of middle hooks on the discs of its representatives. 

 However, there is reason to believe that it equals one pair, i, e, , that it 



sharply differs from other Capsalinae. If this should be proved and, also, 

 if we should take into consideration the peculiarities of the structure of the 

 intestine, of the female sex system, and of certain others, it would be quite 

 probable that this subfamily would have to be transferred to a higher rank, 

 after separating it from the rest of the "tristomid-like" forms. 



2. Subfamily Megalocotylinae Bychowsky subfam. nov. 



(Fig. 278, A, 279) 



Trochopodinae (Price, 1936) Sproston, 1946 part. 



Capsalidae> having the attaching disc with a central, often weakly 

 expressed depression, and an unequal nunnber (mostly 7) of peripheral ones 

 delimited from each other by muscular, sometimes weakly developed septa. 

 The middle hooks number 3 differently developed pairs. The anterior end 

 has a weak or completely undeveloped cephalic lobe, and 2 more or less 

 well-developed suckers, more rarely instead of suckers there are tw^o 

 glandular fields similar to the ones of Dionchus. The intestinal trunks have 

 lateral and interior weakly branching outgrowths, they do not merge at the p_ 377 

 posterior end. The ovary is rounded. There are always 2 testes. 



Parasites of marine fishes, basically Perciformes, more rarely 

 sharks (Carcharhinidae and Squatinidae). 



Type genus, Megalocotyle Folda, 1928. 



In addition to the type genus, 2 more- -Macrophyllida Johnston, 

 1929 and Sprostonia Bychowsky gen. nov. --pertain to this subfamily. 



449 



