Deep H $_{\bf \alpha}$ survey of the Milky Way. III. The l = 338 area

The Galactic plane has been observed between I = 337 degrees and l = 342 degrees in the frame of an H alpha Survey of the Southern Milky Way. This area is known to be rich in radio sources but poor in H alpha emission. The analysis of high resolution profiles of the Her emission observed in this direction nevertheless enabled to distinguish 6 different velocity components: 2 faint layers of diffuse ionized hydrogen at 0 and -12 km s(-1) (V-LSR), 2 brighter layers at -28 and -39 km s(-1) including individual HII regions, a faint patch at -50 km s(-1) and two isolated bright HII regions at -61 km s(-1). Combining these H alpha observations with stellar and radio data we conclude about the most probable distances for the different components.