cochlea vs gastropod

cochlea

noun
  • A spiral-shaped shell, especially that of a snail. 

  • The complex, spirally coiled, tapered cavity of the inner ear of higher vertebrates, which contains the organ of Corti and in which sound vibrations are converted into nerve impulses. 

gastropod

noun
  • Any member of a class of mollusks (Gastropoda) that includes snails and slugs; univalve mollusk. 

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