Hydrodynamical models of elliptical galaxies can be obtained by means of Jeans’equations (see for example Ortega and de Freitas Pacheco, 1986). Following this approach, we consider a mass distribution in steady state which approximates de Vaucouleurs’ r1/4 law, and assume the principal axes of the velocity distribution to be parallel to unitary vectors in cylindrical and spherical coordinates, with the ratio between dispersions in different directions a constant or a function of position.