[New species of parasitic infusoria of the family Urceolariidae].

Three new species of Ciliata of the family Urceolariidae were found as follows: Paratrichodina voikarensis sp. n. on the gills of Coregonus nasus and C. peled; P. uralensis sp. n. on the gills of the sterlet and Trichodina percae sp. n. in the nasal cavities of the perch. Figures and descriptions of the new species are given.