Distribution of internal reddening [E(B−V)_int] for (a) all H II nuclei in our survey, (b) nuclei with types S0–Sbc, (c) nuclei with types Sc–I0, and (d) the sample of disk H II regions of McCall et al. (1985). The bins are separated by 0.1 mag. We estimated the internal reddening in our measurements from the observed Hα/Hβ ratio (see Ho et al. 1997a).