gnathite vs maxilliped

gnathite

noun
  • Any of the mouth appendages of the Arthropoda. 

maxilliped

noun
  • One of the appendages on the heads of centipedes and some crustaceans behind the maxillae, used for feeding. The maxillipeds, known as forcipules, give centipedes their scientific name, Chilopoda (lip-foot). 

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