An excerpt from the entry for "Limax" in the 3rd edition of the Encyclopaedia Britannica published in 1797:
LIMAX, the Slug, or Naked Snail; a genus of insects belonging to the order of vermes mollusca...There are eight species, distinguished entirely by their colour; as the black slug, the white slug, the reddish slug, the ash-coloured slug, &c.
