It's quite late and I'm lazy... have some Wilhelm Foissner instead:
I'm gonna guess them spiraling clockwise inward, starting from Bursaria (the big thing with the gaping oral cavity); take this with a big grain of salt:
Bursaria - Coleps - some other ciliate - testate amoebozoan (some relative of Difflugia?) - suctorian - amoebozoan (Arcella relative?) - some Tetraselmis-like thing? - another ciliate - filose amoeba - Didinium - Euplotes
Check out more of his SEMs if you can... his stuff is amazing!
Sixty-four years later: How Watson and Crick did it
7 hours ago in The Curious Wavefunction