The growth and damping properties of linear magnetosonic (R-mode compressional Alfv¿n) waves are compared for the idealized case of either generalized bi-Lorentzian or bi-Maxwellian fits to solar wind parameters within 1 AU. Measured proton temperature anisotropies (T∥,p>T⊥,p) can provide significant local convective amplification, though only for small angles of propagation to the magnetic field. For more oblique propagation, waves are subject to Landau damping and cyclotron resonant absorption. Since it is unlikely that waves will remain confined to a small cone of propagation over the appreciable distances (~106 km) necessary for significant growth, this confinement could explain the apparent absence of magnetosonic waves in the undisturbed solar wind. ¿ American Geophysical Union 1996