16 Alpha Leonis One

16 Alpha Leonis One was a planet with an atmosphere of carbon dioxide and seas of boiling sulphuric acid. The crystaline sea anemone-like Cthalctose evolved on the planet.

Jason Kane travelled to the planet in the year 6 billion BC, using one of the Seventh Doctor's personal force field emitters to survive its harsh environment. (PROSE: Eternity Weeps)