colubrid vs ophidian

colubrid

noun
  • Any snake in the family Colubridae, completely covered in scales and mostly nonvenomous. 

ophidian

noun
  • Any species of the suborder Serpentes; a snake or serpent. 

adj
  • Of or pertaining to the suborder Serpentes; of, related to, or characteristic of a snake or serpent. 

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