hooks (apparently all four pairs, although so far it has not been possible 

 to detect a pair of the small edge hooks) are preserved together with a 

 strongly reduced appendage, but both suckers (highly reduced to a great 

 extent in the preceeding genus) completely disappear. 



Fig. 49. Leptocotyle minor (Monticelli), 

 adult worm from the skin of the dorsal 

 fin of the young Scyliorhinus canicula (L. ) 

 from the Bay of Naples (Mediterranean 

 Sea). 



Fig. 50. Neopolystoma palpe- 

 brae Strelkow, adult worm 

 from beneath the lower eyelid 

 of Amyda sinensis (Weig. ) 

 from Hanka Lake. 



The ensuing families (Chimaericolidae, Fig. 53; Mazocraeidae, 

 Fig. 24; Hexostomatidae, Fig. 37; Discocotylidae , Fig. 2Z8; Anthocoty- 

 lidae. Fig. 42; Plectanocotylidae , Fig. 88; Diclidophoridae , Fig. 54; 

 Microcotylidae, Fig. 23; Gastrocotylidae, Fig. 7; Protomicrocotylidae, 

 Fig. 89) are characterized by the presence of an attaching disc which is 

 delineated fronn the body of the animal in varying degrees and bears, as a 

 rule, a varying number of chitinous hooks which may be, however, absent 

 in adult forms, and also bearing a varying number of attaching clamps. The 

 number of chitinous hooks fluctuates from one to four pairs and the number 

 of clamps fluctuates from one to several scores (above 100) of pairs. Four 

 pairs of clamps and not more than three pairs of chitinous hooks are charac- 



32 



