  We report the results of a submillimetre continuum emission survey targeted
toward 78 star formation regions, 72 of which are devoid of methanol maser and
UC HII regions, identified in the SEST/SIMBA millimetre continuum survey of
Hill et al. (2005). At least 45 per cent of the latter sources, dubbed
`mm-only', detected in this survey are also devoid of mid infrared MSX,
emission. The 450 and 850micron, continuum emission was mapped using the
Submillimetre Common User Bolometer Array (SCUBA) instrument on the James Clerk
Maxwell Telescope (JCMT). Emission is detected toward 97 per cent of the 78
sources targeted as well as towards 28 other SIMBA sources lying in the SCUBA
fields.
  We concatenate the results from four (sub)millimetre continuum surveys of
massive star formation [Walsh et al. (2003), Hill et al. (2005), Thompson et
al. (2006); as well as this work], together with the Galactic Plane map of
Pierce-Price et al. (2000) in order to determine the dust grain emissivity
index $\beta$ for each of the sources in the SIMBA source list. We examine the
value of $\beta$ with respect to temperature, as well as for the source classes
identified in the SIMBA survey, for variation of this index. Our results
indicate that $\beta$ is typically 2, which is consistent with previous
determinations in the literature, but for a considerably larger sample than
previous work.
