Heliocentric radial velocities (V_R,h) as a function of projected distances to the galaxy centre (d_p). Different symbols represent dwarf (red circles), ellipticals (blue squares), lenticulars (blue-violet triangles), and spirals (green diamonds). The dashed line indicates d_p = 30′, and the dotted one represents the V_R,h for both gEs, ~2800 km s^-1. The grey regions indicate the caustic curves obtained with the Praton & Schneider (1994) infall model for two sets of parameters.