  We present rotation curves for 19, mostly luminous, early-type disk galaxies.
Rotation velocities are measured from a combination of HI velocity fields and
long-slit optical emission line spectra along the major axis. We find that the
rotation curves generally rise rapidly in the central regions and often reach
rotation velocities of 200 - 300 km/s within a few hundred parsecs of the
centre. The detailed shape of the central rotation curves shows a clear
dependence on the concentration of the stellar light distribution and the
bulge-to-disk luminosity ratio: galaxies with highly concentrated stellar light
distributions reach the maximum in their rotation curves at relatively smaller
radii than galaxies with small bulges and a relatively diffuse light
distribution. We interpret this as a strong indication that the dynamics in the
central regions are dominated by the stellar mass.
  At intermediate radii, many rotation curves decline. The strength of the
decline is correlated with the total luminosity of the galaxies, more luminous
galaxies having on average more strongly declining rotation curves. At large
radii, however, all declining rotation curves flatten out, indicating that
substantial amounts of dark matter must be present in these galaxies too.
  A comparison of our rotation curves with the Universal Rotation Curve from
Persic et al. (1996) reveals large discrepancies between the observed and
predicted rotation curves; we argue that rotation curves form a multi-parameter
family which is too complex to describe with a simple formula depending on
total luminosity only. (abridged)
