auricle vs auricula atrii

auricle

noun
  • Synonym of atrium. 

  • The outer ear or pinna. 

  • An anterior ear-shaped appendage of the left or right atrium of the human heart. 

  • Any appendage in the shape of an ear or earlobe. 

auricula atrii

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