We report the first results from a panoramic spectroscopic survey of galaxies in the rich cluster Cl0024+1654 ($z\simeq 0.4$). Using HST imaging we examine the properties of early-types as a function of cluster radius. At all cluster radii, our sample lies on a self-consistent Fundamental Plane whose zero point implies evolution since $z=0$ corresponding to $\Delta[\log (M/L_V)] = 0.14 \pm 0.06$, an overall trend consistent with previous work. Using diagnostic [O II] emission and Balmer absorption lines, we locate a population of intrinsically faint galaxies at 1–2.4 Mpc radius undergoing a period of star formation. The luminosity-dependent radial trends are suggestive of the gradual quenching of star formation for infalling galaxies. We discuss physical mechanisms that may be responsible for this environmental evolution.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html