The parasitic Monogenea of fishes from Sichuan Province. 3. Three new species of Ancylodiscoides Yamaguti, 1937, and Ancyrocephalus (S.L.) Creplin, 1839. Acta Zootaxonomica Sinica, 6(4) 1981: 355-358. 356 [Zoological Record Volume 118]