CO emission in the outer galaxy between longitudes 500 and 720

We have searhced for CO emission from the outer Galaxy between longitudes 500 and 720 at latitude 1.05 spaced every 0.01. These observations are in the same region observed by Kutner and Mead who reported extensive emission from molecular clouds in the outer Galaxy, at galactic radii between 12 and 27 kpc, not seen in previous surveys. We are unable to reproduce their observations. We find only 17 CO lines stronger than T(/sub R/ = 1 K, whereas they report about 225. A comparison with the inner Galaxy at lapprox.290 shows that a single spectrum has more integrated intensity than the sum of 220 spectra at negative velocities in this section of the outer Galaxy. In our 220 spectra, there were no emission lines from galactic radii greater than 15.5 kpc. we find between 0.08 and 0.17 times as much mass in molecular clouds in the outer Galaxy (galactocentric radii 11 kpc<R<15 kpc) as in the inner Galaxy (3 kpc<R<9 kpc)