entozoan vs epizoic

entozoan

adj
  • Of or relating to the Entozoa. 

epizoic

adj
  • In a parasitic way, as an external parasite. 

  • In a nonparasitic way, using an animal's skin as a microhabitat. 

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