In reply to "page-turn text"?:
The ever-helpful Online Etymology Dictionary traces "catch phrase" back to a political meaning of "catchword":
http://www.etymonline.com/index.php?term=catchphrase&allowed_in_frame=0
The interesting thing about catchwords is that they would often match the font and size of the word on the next page, within reason. So even at the bottom of a page of roman text, the catchword could be set in a large blackletter (perhaps even a second ink color) if it's the first word of a large blackletter heading on the next page. So the word actually matched very closely to how it appeared on the next page.