Fimbriaria teresae sp.n. [Cestoda, Hymenolepididae] a new parasite found in Anas clypeata L. in Poland

The description of Fimbriaria teresae sp. n. is given. It differs from the 5 hitherto-described species of the genus Fimbriaria in having 7-10 genital primordia in every segment (one complex of proglottids), as well as deeply-situated genital atria giving the impression of the presence of proglottids. The cirrus pouch, the cirrus and the copulatory part of the vagina of F. teresae sp. n., are also bigger than the same organs in all the previously-described Fimbriaria species. The number of hook-like spines surrounding the base of the cirrus is 8.