The top panel shows the FUV image on the left and Hα image on the right, for the galaxy NGC 3621. We have included contours indicating the optical edge R₂₅. Bottom panel shows the radial profile for the galaxy with FUV emission in dark grey (blue) and Hα in light grey (red), the distance is shown in kpc on the bottom axis and in terms of R₂₅ on the top axis. NGC 3621 was classed as having a truncation in both the Hα and FUV (Tr*-MaTr*), although this feature occurs beyond R₂₅.