The nature of the velocity distribution for molecules emitted from a liquid surface is considered, and the angular dependence of the sticking coefficient for molecules striking the liquid surface is calculated with allowance for the presence of thermally excited capillary waves. Of the various forms of Maxwell distribution that have been assumed to apply to the molecules emitted from a gas-liquid interface, the speed distribution for molecular effusion is most appropriate, but the available experimental data do not allow us to discriminate between this function and "floating" forms of the ordinary Maxwell distribution of speeds. The distribution function for effusion, which is the one normally used in studies of the gas-solid interface, includes a cos theta factor, where theta is the angle between the velocity vector and the normal to the surface. Our work on the kinetics of emission from the liquid surface indicates that the factor should be cos(2) theta for molecules emitted from the liquid. This angular factor has a significant effect on the angular dependence of the sticking coefficient alpha. Comparisons of the observed and calculated angular dependence of alpha at high collision energy clearly favor the form with the cos(2) theta factor over the form with cos theta.