assembly, earlier-type galaxies live in halos with a richer and more varied merger history, that affects both the bulge and the halo mass; this increases the scatter in $\sigma/V_{\rm C}$. Notice, however, how $\sigma/V_{\rm C}$ does not depend on the total circular velocity $W$, for a given morphological type.

We then compare the observed sample in the same space (*squares*). The morphology of the galaxies in the sample is not known, and we use the relation between photometric type and $\sigma/V_{\rm C}$ of the model to classify them: we colour-code the data based on where they lay with respect to the model, in bands of $\sigma/V_{\rm C}$. We assign *blue* colour to the galaxies with very low velocity dispersion, with values of $\sigma/V_{\rm C}$ typical of model Sc galaxies, *red* to the more dispersion-dominated, with values of $\sigma/V_{\rm C}$ typical of model Sa, and *orange* to the intermediate class, typical of model Sb objects. There is a certain degree of overlap in the model, i.e. there are ranges of $\sigma/V_{\rm C}$ that are occupied by both model Sb and Sa galaxies and, to a lesser degree, by both model Sc and Sb (in analogy with Fig. (\[histo\])). We consider the 