Previous analysis of the particle size distribution of lunar surface material has assumed a log-log particle size distribution. A distribution of this type means that, with no bounds set on particle size, the total volume of particles goes to infinity. If there are bounds set on particle size, the mode will be the size interval at one of the extremes. The author believes that this is a highly improbable size distribution and that a Gaussian size distribution is more realistic. Using a Gaussian particle size distribution and 50 percent porosity, plus a surface irregularity correction, the mean particle size at the Surveyor I site is 9.6μ, and the mean particle size at the Surveyor III site is 54μ.