Note: Do not rely on this information. It is very old.
Clio
Clio. 1. One of the Nine Muses, whose special attribute it was to patronise history, and it was, perhaps, for this reason that Herodotus named the first book of his history after her, thus giving her the preference over the other eight. Addison's papers in the Spectator are signed with one or other of the letters composing her name.
2. The name of a boring sponge which riddles the shells of oysters, etc. Though the spicules have not been found fossil, its presence in early times is inferred from the galleries bored through fossil shells.