Emission of CO (a) integrated over the observed range in latitude as a function of velocity and longitude and (b) integrated over the observed range in longitude as a function of velocity and latitude. In both (a) and (b) the lowest contour is at 0.30 K deg, and each contour is 1.58 times higher than the previous, for five contours per decade. In (b) we marked the velocity ranges of the Perseus and local arms, −85 to −25 km s⁻¹ and −25 to 10 km s⁻¹, respectively. The arrows point to the interarm feature near ﹩v_{\mathrm{LSR}\,}=-35\,\mathrm{km\,s}\,^{-1}﹩, ﹩l=108\fdg 9﹩, ﹩b=1\fdg 7﹩ discussed in § 6.4.