encephalon vs telencephalon

encephalon

noun
  • The area of central nervous system that includes all higher nervous centers, enclosed within the skull and continuous with the spinal cord; the brain. 

telencephalon

noun
  • The anterior part of the forebrain; the endbrain. 

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