Comparison of P₂ and the ellipticity, ϵ, calculated from a fit of an elliptical β model to the X-ray image. The blue stars represent those classified as regular, the green diamonds the intermediate, and the disturbed clusters are marked by the red squares. This convention is carried throughout the paper. There is a positive correlation between two parameters. We note that there is a segregation effect which separates regular clusters from the intermediate and disturbed ones.