Finsler geometry is the most natural generalization of Riemannian geo metry. It started in 1918 when P. Finsler 1] wrote his thesis on curves and surfaces in what he called generalized metric spaces. Studying the geometry of those spaces (which where named Finsler spaces or Finsler manifolds) became an area of active research. Many important results on the subject have been brought together in several monographs (cf., H. Rund 3], G. Asanov 1], M. Matsumoto 6], A. Bejancu 8], P. L. Antonelli, R. S. Ingar den and M. Matsumoto 1], M. Abate and G. Patrizio 1] and R. Miron 3]) . However,...