In addition to the middle and lateral hooks and connecting plates, 

 the Diplectanidae also have disc-like growths on the dorsal and ventral sur- 

 faces of the disc (see page 355 ). The attaching apparatus of Tetraonchoi- p. 35 

 didae (page 394 ) and Bothitrematidae (page 395 ) is more connplexly arranged. 



(LImm 



Fig. 41. Pseudoanthocotyle pav- 

 lovskyi Bychowsky and Nagibina, 

 adult worm from the gills of 

 Scomber canagurta Rupp. from 

 the region of the Island Liu-Kiu 

 (East China Sea) (According to 

 Bychowsky and Nagihina, 1954). 



Fig. 42. Anthocotyle merlucii Bene^ 

 dene and Hesse, adult but not fully 

 matured worm from the gills of 

 Merluccius merluccius (L. ) near 

 the western shores of England 

 (Atlantic Ocean) (According to 

 Bychowsky and Nagibina, 1954). 



Among Calceostomatidae, Monocotylidae , Loimoidae, Dion- 

 chidae and Capsalidae the attaching disc represents a more or less developed, 

 well-delineated sucker also provided with lateral and middle hooks as in 

 the previous families. (Calceostomatidae have one pair of middle hooks 

 and twelve edge hooks on their discs. ) Their disc is powerfully developed 

 and provided with a festoon-shaped cutout fringe. Among Monocotylidae 

 there is one genotype (Ennpruthotrema raiae MacCallum, Fig. 15) which is 

 devoid of middle hooks whereas all the remaining species have one pair of 

 middle hooks and 14 edge hooks. As a rule there is no chitinous connecting 

 apparatus. Genera of this family have varying numbers of partitions or 

 septa which separate the suckers into a series of isolated attaching alveoli 

 on the attaching disc, the number of these alveoli varies greatly. Usually 

 there is one lying in the center and from 7 to 100 or more laterally located 

 symmetrically in relation to the longitudinal axis of the attaching disc 



28 



