Selection of fits to the Lyman series for systems D, C, and B at z = 3.346, 3.348, and 3.351, respectively. Lines between the third and tenth orders allow systems C and D to be constrained well. Higher order Lyman-series transitions near the Lyman limit, where system B better is constrained, are shown in Fig. 2. Shaded regions show 0.3 dex deviations from the best fit. Grey vertical lines represent the centres of the corresponding components.