blue sea slug vs glaucus

blue sea slug

glaucus

noun
  • Citrus glauca, the desert lime, a thorny shrub species endemic to semi-arid regions of Australia. 

  • Any member of the genus Glaucus of nudibranchiate mollusks, found in the warmer latitudes, swimming in the open sea, strikingly colored with blue and silvery white. 

How often have the words blue sea slug and glaucus occurred in a corpus of books? (source: Google Ngram Viewer )