Grey-scale representation of the mean Hi brightness temperature in the velocity range −26 to −19 km s^-1. The light dot ellipse represents the least square fit to the Hi peaks defining GS305+04-26. The location of GSH305+01-24 (McClure-Griffiths et al. 2001) is depicted by a dark dot ellipse. The dash-dotted rectangle delimits the region shown in Fig. 5. The small black rectangle shows the position of the star WR 48, . The angular resolution of these data is given by the filled dot drawn in the upper left-hand corner.