Comparison of masses derived from the 875 μm dust continuum as well as via the C¹⁸O(2–1) line width under the assumption of virial equilibrium at the same spatial resolution of 27.5′′. We draw 25% error-bars although the real errors may be even larger as discussed in the main text. The solid line marks the 1:1 relation. The numbers in the bottom-right part correspond to the clumps discussed in the main text and marked in Fig. 4.