Marine vs thalassoid

Marine

adj

  • Of, or pertaining to, a marine corps. 

noun

  • A member of a marine corps. 

thalassoid

adj

  • Synonym of marine 

noun

  • Any small lunar "sea" 

  • Any moth of the genus Thalassodes 

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