Distributions of the −42, −22, −3, 9, and 17 km s⁻¹ clouds. Panels (a)–(e) are the channel maps of the ¹²CO emission line, and panels (f)–(h) are those of the ¹³CO emission line which are made for the same velocity intervals as for panels (c)–(e) in this order. Velocity intervals used for the integration are denoted above each panel. Others are the same as in figure 1. (Color online)