  Finite thin disc models of four galaxies in the Ursa Major cluster are
presented. The models are obtained by means of the Hunter method and the
particular solutions are choosen in such a way that the circular velocities are
adjusted very accurately to the observed rotation curves of some specific
spiral galaxies. We present particular models for the four galaxies NGC3877,
NGC3917, NGC3949 and NGC4010 with data taken from the recent paper by Verheijen
& Sancici (2001). By integrating the corresponding surface mass densities, we
obtain the total mass M of these four galaxies, all of them being of the order
of 10^10 solar masses. These obtained values for M may be taken as a quite
accurately estimative of the mass upper bound of these galaxies, since in the
model was considered that all their mass was concentrated at the galactic disc.
The models can be consider as a first approximation to the obtaining of quite
realistic models of spiral galaxies
