chlamys vs perigone

chlamys

noun
  • A short poncho-like cloak caught up on the shoulder, worn by hunters, soldiers, and horsemen in Ancient Greece. 

perigone

noun
  • perianth 

  • In mosses, the involucral bracts of a male flower. 

  • A sac surrounding the generative bodies in the gonophore of a hydroid. 

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