Observations suggest that plasma can occasionally be transferred from closed to open field lines in the geomagnetic tail during periods when the separatrix between open and closed field lines moves rapidly toward decreasing latitudes. Such transfer would require E⋅J0. We have recently shown that gyroviscosity can provide the force required to balance the electric force along an X line having E⋅J>0. Here we extend this previous analysis of gyroviscosity to the case where E⋅J<0 along an X line. We show how the balance between gyroviscosity and the electric force along an X line is maintained for any E⋅J. We conclude that observational evidence for the occasional existence of E⋅J<0 along an X line provides support for the suggestion that collisionless gyroviscosity, rather than resistivity, balances the electric force along an X line. We also evaluate conditions for which particle motion in the vicinity of an X line can give a current in the direction appropriate for E⋅J<0, and we find that there is maximum electric field magnitude for particles to be able to carry a significant current. For parameters typical of the distant magnetotail the critical electric field magnitude was found to be ~0.15 mV/m, which is of order of, though somewhat less than, the potential electric field magnitudes expected in the magnetotail. This maximum allowable field magnitude is about the same for protons as it is for electrons in the magnetotail. ¿ American Geophysical Union 1992