  We report the discovery of eleven new variable DA white dwarf (ZZ Ceti)
stars. Candidates were selected by deriving temperatures from model fits to
spectra obtained from the Sloan Digital Sky Survey. We also find objects whose
temperatures and gravities indicate they lie within the instability strip for
pulsation, but which were not observed to vary. Although the temperatures are
based on relatively low S/N spectra, an impure strip is unexpected, and if
confirmed suggests that our knowledge of the pulsation mechanism is incomplete.
This work brings the total number of published variable DA white dwarf stars to
82.
