Å. The spectra in the Treu et al. sample have higher $S/N$ than the typical LRG spectrum, but the wavelength coverage is better for the LRG sample (see example in Figure 3). To select potentially passively evolving galaxies, we include only galaxies with $S/N > 9$ per Å and for which passively evolving synthetic stellar population models [@JPMH98] provide a good fit to the continuum. This selection criterion discards dusty or star-forming objects. The spectra of seven red galaxies in the cluster MS1054$-$0321 were obtained by one of us (DS) on UT 11 March 2002 using the dual-beam Low Resolution Imaging Spectrometer [LRIS; @Oke+95] at Keck Observatory. On the blue side, we used the 300 lines mm$^{-1}$ grism ($\lambda_{\rm blaze} =
5000$ Å; spectral resolution $\Delta \lambda_{\rm FWHM} \approx
13.5$ Å) and on the red side, we used the the 400 lines mm$^{-1}$ grating ($\lambda_{\rm blaze} = 8500$ Å; spectral resolution $\Delta
\lambda_{\rm FWHM} \approx 8$ Å). These observations, which were obtained at the parallactic angle, totaled one hour of integration. In order to ensure no gaps in the spectra, half the data were obtained with a D560 dichroic and the remainder were obtained with a D680 dichroic. These spectra 