Regions of interest for RXC J0225. Regions R1 and R2, which do not contain any significant galaxy overdensity, were used to estimate the average surface density of field galaxies. The latter is used to correct the richness of each substructure. The elliptical regions labelled G1–G7 are the substructure candidates identified by the galaxy overdensities in the optical maps, and/or from the Δ-tests. The contours trace the surface density of the bright red-sequence galaxies (starting at 5σ and omitting the two innermost levels, for clarity). Symbols show the location of the spectroscopic members associated with the different KMM partitions. The dashed circle has a radius of R₂₀₀ ~ 2 Mpc.