New techniques are developed for a rough but rapid determination of position angle, ellipticity, compactness, and center of distribution of galaxies in a cluster.These methods are applied to clusters associated with supergiant (Morgan cD) galaxies.There is a strong tendency for the major axis of the distribution of galaxies to be oriented along the major axis of the cD galaxy.The relative compactness of brighter and fainter members indicate that the radio cD clusters are dynamically younger than the nonradio cD clusters.In the last decade Zwicky ( 1957, 1964 ) has extensively studied the distribution of galaxies in nearby clusters, such as the Coma and Cancer clusters and the cD cluster around NGC 541, on 18-inch and 48-inch Schmidt telescope plates.Abell (1958) has prepared a catalog of rich clusters using the original Palomar 48-inch Schmidt Sky Survey plates.Recently, Noonan (1961) reinterpreted Zwicky's counts of Coma Cluster galaxies to derive the structure of that cluster.This structure was confirmed by means of independent counts by Omer, Page, and Wilson (1965).Rood (1965), using
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Gummuluru N. Sastry (1968) studied this question.