cotylidae but also from the majority of Monogenoidea. We observe 

 similar structure of the ovary among several forms, as for instance 

 some Calceostomatidae [ Calceostoma calceostoma (Wagener)] and the 

 highly organized Chimaericolidae, belonging to a conmpletely different 

 group. Price (Price, 1936 and 1938a) isolates Loiinos into a special 

 subfamily of Monocotylidae--Loimoinae; however, he did not see many 

 peculiarities of these worms. Corrections and additions to his des- 

 cription made by Manter in 1944 show, in spite of the opinion of both 

 authors, that the unification of Loimoinae w^ith the rest of the Mono- 

 cotylidae is erroneous and this group must be considered as a separate, 

 very specialized family standing somewhat apart in the system of Mono- 

 pisthocotylinea. We are not at all convinced that its attribution to the sub- 

 order indicated is fully justifiable, for even though we write about the 

 probability of the presence of 14 edge hooks, this has not yet been proved. 

 Thus, one must not underevaluate the sinailarities which exist in the 

 structure of Loimoidae and Calceostomatidae, and in particular the 

 peculiarities of the structure of the sex system, and of the attaching 

 apparatus. As we have already indicated above, the ovary of Loimoidae 

 resembles the one of Calceostoma calceostonna, the absence of the 

 connecting plate between the middle hooks is peculiar also for Calceo- 

 stomella inermis (Parona and Perugia) etc. Perhaps only the 



nature of the location of the middle and edge hooks of the disc, if Manter's 

 above-mentioned drawing is correct, will provide us with greater certainty p. 372 

 of the correctness of the isolation of Loimoidae to Monopisthocotylinea and 

 not Dactylogyrinea. The occurrence of the family of Elasmobranchii serves as 

 indirect evidence in favor of this also. 



3. Family Dionchidae Bychowsky fam. nov, 



(Fig. 16) 



Monocotylidae Taschenberg, 1879, part. , Dionchmae Johnston 

 and Tiegs, 1922. 



Monopisthocotylinea, having middle sizes in adult state. Attaching 

 apparatus consists of a sucker-shaped disc divided along the periphery by 

 10 (?)-14, incomplete septa into a number of separate parts, and bearing 

 chitinous armature which consists of 14 edge hooks and 2 middle hooks. 

 All the edge hooks lie along the periphery of the disc and at the places of the 

 termination of the septa and the transition of their nnusculature into the 

 musculature of the edge of the disc. In connection with this, only one pair 

 of edge hooks lies between the septa in which the middle hooks are located 

 (and one pair of edge hooks) at the posterior edge of the disc. The anterior 

 end of the body is linguaform with 2 relatively long glandular zones into 

 which numerous cephalic glands open. The buccal opening lies on the 

 ventral side and lacks an adoral sucker. There are 4 eyes. The intestine 



443 



