We present new BVR integrated magnitudes and color indices for 75 globular clusters and cluster candidates in the halo of M31. These have been measured by CCD imaging at the KPNO 0.9 m telescope. The aperture growth curves, image morphologies, and locations in the (B - V,V - R) two-color plane are used along with other information in the literature (radial velocities, degree of resolution into stars) to help identify background galaxies and other types of contaminating objects, and to remove them from the cluster sample. The "cleaned" sample is used along with previously published material to construct a preliminary luminosity function for the halo clusters in M31. There is some indication that the peak frequency or "turnover" point for the M31 globulars may be as much as approximately 0.2 mag more luminous than for the Milky Way halo clusters. This conclusion is, however, quite uncertain because of incompleteness in the faint half of the sample, which (in agreement with previous authors) we find to persist despite extensive efforts to survey the M31 halo. Finally, we suggest how the "missing" faint-halo clusters might be located from the existing catalogs.