Observations on the popular antiquities of Great Britain, vol. 3Edit
The original word rem, translated unicorn in our version of the book of Job, xxxix. 9, is by Jerome or Hierome, Montanus, and Aquila rendered rhinoceros; in the Septuagint, monoceros, which is nothing more than "one horn." I have no doubt but that the rhinoceros is the real unicorn of antiquity. The fabulous animal of heraldry so called, is nothing more than a horse with the horn of the pristis or sword fish stuck in his forehead.
This short snippet earned an honorable mention in Odell Shepard's "The Lore of the Unicorn" for the most "dense and audacious error". The author has probably confused several marine animals. "Pristis" is another name for a sawfish; the swordfish is called "xiphias". The horn of the unicorn looks nothing like the parts of those creatures. Brand would have been partially correct if he mentioned a narwhal (Monodon monoceros) instead.
The original identity of the re'em is a more complicated matter; most scholars agree that it is of bovine nature.