Sororities that dropped out of NPC?

[CutiePie2000]

There is an old thread that talks about old chapters which were absorbed into the NPC sorority Delta Zeta. The only sorority that I know of that was in the NPC and is no longer, is Iota Phi Theta (correction made later that day: I meant "Iota Alpha Pi"...sorry about my mistake), and I think it was absorbed into another NPC, though I cannot say for sure.