The spectrum displayed like this shows a shift from mythology (which I suspect is qualified in this structure as the earliest incarnation of idea/story) to fairy tale (not so close to the original idea/story in the ether).
I, on the other hand, find so much depth in the wealth of fairy tale resources that I tend to lump them into the broader mythology category (as you may have noticed in my "Essay for Karen" post). Vampires and werewolves get lumped in there, as well. In order to address my tendency to put them all in the same category, I thought I'd do a little research.
Where better to start than the Dewey Decimal System? The system baffles me on some of its qualifiers, as I've noticed them on the shelves. Why do books on American Indian religion appear in the 290s, but books of American Indian legends are shelved in the 398.2s?* I used my investigative skills and asked the cataloger at the library why it all worked, and she supplied me with a most excellent Dewey Decimal index that elaborates on what goes where. (I'd always thought cataloging was quite mysterious, but the index is a great demystifier.)
Here's the basic scoop: the 290s are "Religions other than Christianity." 292: Classical Religion (read: Greek and Roman mythology). 293: Germanic Relgion (Teutonic mythology, Norse mythology). 294: Religions of Indic Origin (Buddhism, Hinduism, and Sufiism are all here). 295: Zoroastrianism. 296: Judiasm. 297: Islam. (Christianity doesn't get all of 200-290, but it's pretty darn close. Which tells you a bit about Mr. Dewey's worldview.)
The 398s, on the other hand, are folklore. Anything dealing with superstitions, folktales about characters, folktales about specific creatures (I think that's 398.4), riddle games, rhyming games, etc., finds its home between 398 and 400.
I have some conclusions that I've drawn from this, but I'd like to open it to discussion first. After all, I was talking for awhile about writing a dissertation on this stuff (if I could find a religion program that would get behind me on it), so I've probably got more to say than anyone is particularly interested in hearing on the subject. It also means I'm interested in hearing what other folks have to say on the topic!
*I use American Indian rather than Native American here, in part because of the national museum in DC, and in part because of a very compelling argument posted, weirdly, by the Antiques Road Show; the full reasoning will appear over on the Cowboys and Aliens bonus pages in the next few weeks, and if you're interested, I'll post a link when it's up.