archenteron vs calyx

archenteron

noun
  • A primitive alimentary cavity 

calyx

noun
  • A funnel-shaped expansion of the vas deferens or oviduct of insects. 

  • A chamber in the mammalian kidney through which urine passes. 

  • The outermost whorl of flower parts, comprising the sepals, which covers and protects the petals as they develop. 

  • The crown containing the viscera of crinoids and similar echinoderms, entoprocts, and the polyps of some cnidarians. 

  • A flattened cap of neuropil in the brain of insects. 

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