Phantom menu links?

Overnight, I've had for extra links appear in my menu named "page one," "page two", "page three", and "page four." They link to nothing.

I have 3 actual pages in my Pages folder - Tenets, Colophon, About - all of which show up. I also added a link to the home page through the dashboard which also appears

There are 5 image files in the pages folder, all prefixed with and underscore. So... not sure where those are coming from? Where should I look to remove them?