  We present observations of fifty square degrees of the Mopra carbon monoxide
(CO) survey of the Southern Galactic Plane, covering Galactic longitudes $l =
300$-$350^\circ$ and latitudes $|b| \le 0.5^\circ$. These data have been taken
at 0.6 arcminute spatial resolution and 0.1 km/s spectral resolution, providing
an unprecedented view of the molecular clouds and gas of the Southern Galactic
Plane in the 109-115 GHz $J = 1$-0 transitions of $^{12}$CO, $^{13}$CO,
C$^{18}$O and C$^{17}$O. We present a series of velocity-integrated maps,
spectra and position-velocity plots that illustrate Galactic arm structures and
trace masses on the order of $\sim$10$^{6}$ M$_{\odot}$ per square degree; and
include a preliminary catalogue of C$^{18}$O clumps located between
$l=330$-$340^\circ$. Together with information about the noise statistics of
the survey these data can be retrieved from the Mopra CO website, the PASA data
store and the Harvard Dataverse (doi:10.7910/DVN/LH3BDN ).
