  Velocity distributions in a vibrated granular monolayer are investigated
experimentally. Non-Gaussian velocity distributions are observed at low
vibration amplitudes but cross over smoothly to Gaussian distributions as the
amplitude is increased. Cross-correlations between fluctuations in density and
temperature are present only when the velocity distributions are strongly
non-Gaussian. Confining the expansion of the granular layer results in
non-Gaussian velocity distributions that persist to high vibration amplitudes.
