eidolon vs manes

eidolon

noun
  • A phantom, a ghost or elusive entity. 

  • An image or representation of an idea; a representation of an ideal form; an apparition of some actual or imaginary entity, or of some aspect of reality. 

  • An unsubstantial image, spectre, phantom. 

manes

noun
  • The souls or spirits of dead ancestors, conceived as deities or the subjects of reverence, or of other deceased relatives. 

How often have the words eidolon and manes occurred in a corpus of books? (source: Google Ngram Viewer )