penfish vs rectrix

penfish

noun
  • A squid. 

  • Any of various porgies of the genus Calamus 

rectrix

noun
  • A flight feather on the tails of birds, used for directional control. 

  • A governess; a rectoress. 

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