scutum vs squama

scutum

noun
  • A scute. 

  • The kneecap. 

  • One of the two lower valves of the operculum of a barnacle. 

  • An oblong shield made of boards or wickerwork covered with leather, with sometimes an iron rim; carried chiefly by the heavily armed infantry of the Roman army. 

  • A shield-like protection, such as the scutum protecting the back of a hard tick (cf. alloscutum, conscutum) 

squama

noun
  • Any scaly bracted leaf. 

  • A scale cast off from the skin; a thin dry shred of epithelium. 

  • The bract of a deciduous spike. 

  • A calypter. 

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