1 



The indication of the host demands verification, because undoubtedly 

 the eggs of Arius are not the normal place of habitat of the species. 



references. The characteristics which liken this monotypic genus to 

 Calceostomatidae are the shape and peculiarities in the structure of the 

 intestine, and also the presence of relatively very small middle hooks 

 located in the center of the disc. The indication of the absence of edge 

 hooks is apparently erroneous, and their presence and subsequent count 

 will show the correctness of the attribution of this genus to the present 

 family. 



The correctness of the inclusion of the present family into 

 Dactylogyridae remains unclear to us because the presence of 12 edge 

 hooks on the attaching disc and a number of other peculiarities point to 

 a considerable singularity of the family from the rest which enter into the 

 circle of the present order. It is quite possible that separation into a 

 special order w^ould have been more correct, but it is impossible to do 

 this at the present time without special nnorphological study even if it 

 requires going to the basic genera. Consequently, we retain Calceo- 

 stomatidea conditionally within the limits of Dactylogyridea. It should 

 also be completely clear that their attribution to Dactylogyrinea is not 

 less conditional and is made on the basis of greater similarity between 

 the nnorphological structures of Calceostomatidae with the ones of the 

 lowest Dactylogyridea, 



2. Suborder Monopisthocotylinea (Odhner, 1912) 

 Bychowsky, 1937 



Dactylogyridea, having larvae with 14 edge hooks. Adult forms 

 with attaching armature consisting of 14 edge hooks and 1-3 pairs of 

 middle hooks. Connecting plates are absent. In rare cases the attaching 

 armature can be completely absent (Microbothriidae), As a rule the 

 attaching disc is transformed into a more or less powerful sucker which 

 serves for attachment independently of the retention of the chitinous 

 armature among the adult aninnals. There are cases when the true 

 attaching disc is replaced during development by a false one which develops 

 above on the body of the animal and which assumes the function of attaching 

 the adult animals (Acanthocotylidae), The intestine is in the shape of two 

 trunks merging or terminating blindly, often forming lateral outgrowths 

 and little anastomoses. 



Parasites of marine and fresh water Elasmobranchii and 

 Teleostomi. 



482 



