only within the limits of the family which is under study, and thus 

 appears as their most important characteristic as has been indicated before. 

 The second innportant characteristic of the family which is under study, 

 strange as it nnay be, is a special type of armature of the copulatory organ. 

 Generally speaking this can hardly be considered as an important character 

 for the highest Monogenoidea because we know that the armature of the 

 copulatory organ and of the sex atrium as a whole varies a great deal; 

 however, in Mazocraeidae we observe a surprising constancy in this 

 connection. In all the genera, the copulatory organ is armed with two 

 large sickle-shaped thorns lying anteriorly along the sides of the sex 

 cone (it is possible in the walls of the sex atrium) and usually within a 

 row of much smaller little thorns lying somewhat posteriorly as is seen 

 in the corresponding drawings (see Fig. 298). The exception is formed 



by Grubea in which the copulatory 

 organ is represented, judging by the 

 drawing of Palombi (Palombi, 1949), 

 as a little corona of single hooks. 

 Generally the status of this group in 

 the system is not clear to us. We 

 don't have our own material and the 

 attribution of this genus is made 

 conditionally, following Sproston 

 (Sproston, 1946). If the data of 

 Palombi are correct, and we have 

 no basis to doubt it in this case, it 

 is most probable that the genus Grubea 

 should be removed from the composition 

 of the present family. We do not do this 

 only because we do not want to make 

 a change which is not very convincing 

 in this connection without any special 

 research. 



Fig. 297. Mazocraes alosae 



Hermann, structure of the attaching 

 clamp, I--Chitinous parts of the 

 capsule of the attaching clamp sepa- 

 ratedand slightly compressed; on the 

 top the anterior "valve" and on the 

 bottom the posterior; II- -Separate 

 chitinous parts of capsule of the 

 attaching clamp, explanation in text. 



The genera Mazocraes and 

 Octostoma are very close to each 



united these genera. 



other and differ almost exclusively by the 

 fact that in the first there are vaginal 

 ducts, whereas in the second there 

 are none all the remaining characters 

 are completely secondary, in connection 

 with which it is not fortuitously that 

 Palombi and certain other authors 

 The genus Neomazocraes in its turn is very close to 



Mazocraes with which it is united by the presence of vaginal ducts and the 

 nature of the posterior end of the body. The differences of both genera 

 consist mainly in the somewhat different structure of the chitinous capsule 

 of the clamps. Undoubtedly iPseudoanthocotyle reaches the highest special- 



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