cryptozoic vs unseen

cryptozoic

adj
  • Hidden (especially in the soil); not easily visible. 

  • Living in a cavity or small cave. 

  • Relating to a cryptozoite. 

unseen

adj
  • Not seen or discovered; invisible. 

  • Unskilled; inexperienced. 

  • Not hitherto noticed; unobserved. 

noun
  • An examination involving material not previously seen or studied. 

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