We investigate the propagation of volume polaritons in a ferromagnetic slab magnetized to saturation, by means of a short wave-type approximation.The set of equation which governs the wave behavior is shown to be (2+1)-dimensional generalization of the sineGordon equation.It depends on the direction of the applied magnetic field H0:a term accounting for a transverse drift appears when H0 is in the plane of the slab [1], which is absent if it is perpendicular to it.The derivation shows that neither the damping nor the demagnetizing field have an appreciable effect on the wave propagation.Line-solitons can propagate, the conditions for their transverse stability is established.The threshold value of the soliton parameter below which the soliton is stable depends on the direction of the applied field H0.The unstable line soliton evolves into stable two-dimensional localized solitary waves, or lumps.These are described by means of both a numerical and a variational approach.Interactions between the lumps are also mentioned.