cryptozoic vs shrouded

cryptozoic

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

  • Living in a cavity or small cave. 

  • Relating to a cryptozoite. 

shrouded

adj
  • Concealed or hidden from sight, as if by a shroud. 

  • Wearing, or provided with a shroud. 

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