  We discuss the morphology, photometry and kinematics of the bars which have
formed in three N-body simulations. These have initially the same disc and the
same halo-to-disc mass ratio, but their haloes have very different central
concentrations. The third model includes a bulge. The bar in the model with the
centrally concentrated halo (model MH) is much stronger, longer and thinner
than the bar in the model with the less centrally concentrated halo (model MD).
Its shape, when viewed side-on, evolves from boxy to peanut and then to
X-shaped, as opposed to that of model MD, which stays boxy. The projected
density profiles obtained from cuts along the bar major axis, both for the
face-on and the edge-on views, show a flat part, as opposed to those of model
MD which are falling rapidly. A Fourier analysis of the face-on density
distribution of model MH shows very large m = 2, 4, 6 and 8 components.
Contrary to this for model MD the components m = 6 and 8 are negligible. The
velocity field of model MH shows strong deviations from axial symmetry, and in
particular has wavy isovelocities near the end of the bar when viewed along the
bar minor axis. When viewed edge-on, it shows cylindrical rotation, which the
MD model does not. The properties of the bar of the model with a bulge and a
non-centrally concentrated halo (MDB) are intermediate between those of the bar
of the other two models. All three models exhibit a lot of inflow of the disc
material during their evolution, so that by the end of the simulations the disc
dominates over the halo in the inner parts, even for model MH, for which the
halo and disc contributions were initially comparable in that region.
