;Contents: Research on the nervous echolocation mechanism in bats; Interaction of analyzers in dolphins during discrimination of geometrical figures under water; The location signals of bats native to the U.S.S.R.; The relationship between auditory perception and echolocation during hunting in Myotis oxygnathus; Types and formularies of experiments to be carried out in order to obtain comparative results; Mechanisms of overcoming interference in echolocating animals; Main directions in the evolution of locational systems in bats.