  Recent CO measurements of an essentially complete sub-sample of galaxies from
the SCUBA Local Universe Survey (SLUGS) are used to examine their implications
for dust and gas masses in this sample. Estimates of dust masses are affected
by a contribution to the SCUBA brightness measurements by CO(3-2) emission, and
molecular gas masses by the use of a modified value of the CO-to-H_2 conversion
factor X. The average dust mass is reduced by 25-38 per cent, which has no
bearing on earlier conclusions concering the shapes of the dust mass luminosity
function derived from the SLUGS. The value of X found from the CO survey, when
applied together with the reduction in dust masses, leads to lower estimates
for the mean gas-to-dust mass ratios, where the gas includes both H_2 and HI.
For the CO sample, the mean global ratio is reduced from approximately 430 to
about 320-360, but is further reduced to values near 50 when applied to the
nuclear regions relevant to the CO observations. We discuss these results and
suggest that the differences between the nuclear and outer regions may simply
reflect differences in metallicity or the existence of considerable amounts of
unobserved cold dust in the outer regions of these galaxiies.
