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Additional results are reported for a photographic photometry study of 12 very rich clusters of galaxies. From the spatial distributions of the galaxies, it is concluded that the core radius may be well correlated with the overall cluster size, suggesting that the more easily determined core parameters may adequately describe the large-scale cluster characteristics. This study confirms previous results that the size of the core radius is similar among different clusters, but does not agree with earlier work on the precise value of the mean core radius. The observation that cD clusters as a whole tend to be flattened and aligned with the axes of centrally located, highly elliptical cD galaxies is briefly discussed in connection with cD formation mechanisms. M/L ratios of 100-300 for eight clusters with known velocity dispersions are consistent with other studies. M/L is not found to be a function of cluster richness. A crude scheme for the morphological classification of galaxies based on discrimination between ellipticals and nonellipticals in the clusters provides a few possible counterexamples to Oemler's (1974) three distinct population types of clusters.
Alan Dressler (Wed,) studied this question.