Histogram of the dust mass distribution for the 134 of our GDCs with reliable mass measurements; individual mass values of the GDCs are indicated by the ticks in the rug plot. The bin size of 0.17 dex corresponds to our median mass uncertainty. The shaded bars indicate the subsample of 86 GDCs associated with HII regions from D88; individual values of these GDCs are indicated in white in the rug plot. The dashed vertical line indicates the median mass value of 4.6 × 10³M_⊙ for the entire sample and the vertical dotted line indicates our mass completeness limit of 3.8 × 10³M_⊙ .