Darryl Jones. For whatever weird reason they’ve never officially made him a Stone. I have no idea what went into that. But it’s why he doesn’t take the bow with the band. Of course not being officially a Stone has freed him up to work with others, like Ziggy Marley and Neil Young. So there’s that.
Makes sense if that was his motivation to not officially join. Sure he has been invited over the years, as was Ron Wood.