representative of photospheric calcium (and thus the wavelength of the maximum absorption of this component represented ), fit a single Gaussian to the entire profile to measure . Among other claims, reported a linear relationship between  and light-curve shape (3.4-$\sigma$ significant). Furthermore, they claimed that after correcting for the relation between light-curve shape and , there is no correlation between  and host-galaxy mass.

In this paper, we examine the claims of with particular scrutiny to the details of the Ca H&K profile. In Section \[s:cahk\], we re-examine the sample. We confirm a difference in the Ca H&K line profile for SNe Ia with different light-curve shapes, but show that the difference is primarily in the blue component. We also conclude that single-Gaussian fits to the Ca H&K feature give biased, unphysical velocity measurements. In Section \[s:synow\], we provide simple models of calcium and silicon features in a SN Ia spectrum. Trends in the spectra indicate that the blue component of the Ca H&K feature is likely from [Si$\,$]{} $\lambda 3858$. In Section \[s:m12\], we perform further analysis with the sample, finding systematic biases in single-Gaussian velocity measurements appear to be present in the analysis. In Section \[s:cfa\], we re-examine the 