Column densities of dominant species O I, Mg II, P II, Zn II, Ti II, and Fe II vs. N(H_tot) for Galactic sight lines. The stars denote the sight line toward HD 62542: red = main (14 km s⁻¹) component; green = all other components; blue = all components. The solid lines show weighted and unweighted fits to the data (not including the Sco-Oph and Trapezium sight lines); the dotted lines have slope = 1. Toward HD 62542, the column densities of all but O I are clearly deficient, relative to the general Galactic trends, reflecting the enhanced depletions of those species in this unusual sight line. The column densities for Mg II and for the more refractory Ti II and Fe II are particulary low in the main component, indicating very severe depletions there; P II and Zn II also lie below the general trends. Note also the lower abundances of Ti II in the Sco-Oph sight lines (Welty & Crowther 2010).