There are no titles for the individual simanim in the Tur but the simanim in the Shulchan Aruch have titles given by the Mechaber himself.
Siman 552 is Din Erev Tish'ah Be-av, and Siman 553 is Din Seudat Hamafseket.

However, from a casual reading of those two simanim in the Shulchan Aruch it seems to me if anything, siman 552 is almost exclusively about the se'udat hamafseket, and siman 553 is almost exclusively about erev tsihah beav other than the seudat hamafseket. Does anyone else agree?