  It is pointed out that electrostatic and electromagnetic waves propagating in
perpendicular direction to the density gradient $\nabla n_0=\hat{x}
|\frac{dn_0}{dx}|$ and external magnetic field $\vec{B}_0=B_0 \hat{z}$ in
hybrid frequency range $\Omega_i \ll \omega \ll \Omega_e$ (where
$\Omega_j=\frac{eB_0}{m_j c}$ and $j=e,i$) have several applications in space
and laboratory plasmas. The electron plasma waves are important for the future
experiments on heavier ion plasmas as well as the results are applicable to the
experiments performed to create pure pair ion fullerene plasmas. The
electrostatic modes are shown to exist in upper F-region of terrestrial
ionosphere and electromagnetic waves are applied to cylindrically bounded heavy
ion plasmas.
