In mythology, the salamander had the ability to survive fire, to be "fireproof." In Bullfinch's Mythology, in Chapter 36, Bullfinch discusses the origin of the myths surrounding the salamander and the properties it was said to have:
The following is from the "Life of Benvenuto Cellini," an Italian artist of the sixteenth century, written by himself: "When I was about five years of age, my father, happening to be in a little room in which they had been washing, and where there was a good fire of oak burning, looked into the flames and saw a little animal resembling a lizard, which could live in the hottest part of that element. Instantly perceiving what it was, he called for my sister and me, and after he had shown us the creature, he gave me a box on the ear. I fell a-crying, while he, soothing me with caresses, spoke these words: 'My dear child, I do not give you that blow for any fault you have committed, but that you may recollect that the little creature you see in the fire is a salamander; such a one as never was beheld before to my knowledge.' So saying he embraced me, and gave me some money."
I have provided the link to this chaper below, and there are several more paragraphs about the salamander.
How does the salamander fit into Fahrenheit 451? Does the salamander represent Montag? Does the salamander represent the ideas that cannot be destroyed by fire? This symbol would make an interesting topic for a paper.