  (abridged) Photometry and long-slit spectroscopy are presented for a sample
of 6 galaxies with a low surface brightness stellar disc and a bulge. The
stellar and ionised-gas kinematics were measured along the major and minor axis
in half of the sample galaxies, whereas the other half was observed only along
two diagonal axes. Spectra along two diagonal axes were obtained also for one
of the objects with major and minor axis spectra. The kinematic measurements
extend in the disc region out to a surface-brightness level mu_R~24mag/arcsec^2
reaching in all cases the flat part of the rotation curve. The stellar
kinematics turns out to be more regular and symmetric than the ionised-gas
kinematics, which often shows the presence of non-circular, off-plane, and
non-ordered motions. This raises the question about the reliability of the use
of the ionised gas as the tracer of the circular velocity in the modeling of
the mass distribution, in particular in the central regions of low surface
brightness galaxies.
