2. Loimoidae Bychowsky fam. nov. 

 (Fig. 20) 

 Monocotylidae Taschenberg, 1879, part. , Loimoinae Price, 



1936. 



c 



Monopisthocotylinea, having middle sizes in adult state. The 

 attaching apparatus consists of a sucker-shaped disc, bearing armature 

 consisting of 2 middle, and supposedly, 14 edge hooks; 4 of them along the p. 371 

 posterior edge between the middle hooks as among Monocotylidae. On 

 the dorsal side of the disc there are two pairs of half-rounded chitinized 

 ribs, sometimes they are weakly noticeable or absent. The anterior end 

 is with 1-3 pairs of sucker-shaped depressions located on the dorsal 

 edge of the weakly expressed pre -oral sucker with the opening facing the 

 ventral side. The eyes are absent. The intestine with 2 branches not 

 forming offshoots and ending blindly. The male sex aperture and the 

 opening of the uterus open medially. The copulatory organ with a simple 

 central chitinous pipe. The testis is single, follicular, or there are 

 several of them. The ovaries branch, consisting of a number of separate 

 curved little pipes. The vaginal duct is single. 



Parasites of sharks (Sphyrnidae and Carcharhinidae ). 



Type genus, Loimos MacCallum, 1917. 



One more genus, Loimoisina Manter, 1944, enters into the 

 composition of the family in addition to the type genus. 



The few representatives of this new family, which is separated 

 by us fronn Monocotylidae, were poorly described as a whole, conse- 

 quently nnuch of their morphology remains mysterious. The more detailed 

 data appear in the works of Manter (Manter, 1938 and 1944) which we must 

 use as a basis because of the lack of the material itself. The 



attaching apparatus of Loimoidae lacks division into separate sections 



by the septa, which differentiates it from the one of Monocotylidae. How- 

 ever, the location of the middle hooks and their correlations with the edge 

 hooks is of similar nature to that of Monocotylidae. Both families can be 

 completely separated by the presence of the special half-rounded, rib- 

 shaped convex formations on the dorsal side of the disc of Loimoidae, which 

 are apparently of chitinous nature, and which have, as is apparent from the 

 drawing of Manter (Manter, 1944, Fig. 7) a complex structure. Only the 

 sucker-shaped growths of the dorsal side of the disc of Tetraonchoididae 

 (see page 394) are analogous to these formations. What has already been 

 said above forces us to doubt the attribution of Loimos and Loimosina to 

 Monocotylidae; however, besides this these genera also differ by the 

 singular structure of the ovary, which are different not only from Mono- 



442 



