Ancyrocephalus (s. lat. ) hemibarbi Achmerow--The larvae of 

 this species were obtained by A. V. Gussew of Lake Hanka in 1948-1949. The 

 embryonic development (in hanging drops) required 4 to 5 days. The larva 

 has three zones of cilia. The attaching disc is equipped with 7 pairs of 



p. 157 



^OBIhm' 



Fig. 158. Ancyrocephalus (s. lat.) 

 mogurndae (Yamaguti), attaching 

 armature of the disc of an adult 

 worm from the gills of Siniperca 

 chua-tsi (Bas. ) from the Island 

 of Hanka. 



(WImm 



Fig. 159. Ancyrocephalus (s. lat. ) 

 curtus Achmerow, attaching 

 armature of a free-swimming 

 larva. (According to Gussew, 

 1955). 



edge hooks, 0. 012 to 0. 014 mim in length and one pair of powerful sabre- 

 shaped inceptions of the ventral middle hooks (Fig. 163); the length of the 

 latter is about 0. 025 mm. The adult worms, which parasitize the same 

 fishes as the preceding type, have the usual attaching arnnature (Fig. 164). 



Fig. 160. Ancyrocephalus (s. lat. ) pavlovskyi Gussew, attaching arma- 

 ture of the disc of an adult worm. (According to Gussew, 1953). 



The edge hooks are also of two types^ however, the difference between 

 them is considerably less than among A. pavlovskyi Gussew. Thus there 

 are only two small hookS; the 6th pair. Their length is 0.016 to 0.018 

 mm. All the remaining hooks have a length of 0. 025 to 0. 039 mm (the 

 smallest among them is the 7th pair). 



167 



