Phyllobothrium discopygi n. sp. (Cestoda: Tetraphyllidea) from Chile, with acritical comparison of the affinities of P. auricula van Beneden, 1858 and P. foliatum Linton, 1890. Systematic Parasitology, 10(2) 1987: 159-164. 160 [Zoological Record Volume 124]