We report a re-examination of observations of radio waves and banded fine structure observed by Cassini in the Saturn inner magnetosphere. These emissions have been identified in the past as Z-mode emission from possible density cavities along the inner edge of the Saturn plasma torus. A careful examination of the emission fine structure in a region where the ratio of plasma to cyclotron frequency f p /f ce < 1 suggests that the emission bands may be due to eigenmode trapping from density enhancement source regions. The observations are similar to those made at both the Earth and Jupiter and suggest that radio emission fine structure is a remote diagnostic of density fluctuations in planetary magnetospheres.