Well, that is happening as we speak. In Cesare Emiliani's Planet Earth  Cosmology, Geology, & the Evolution of Life & the Environment he described a series of close related species that reproduce circulary in one direction but not in the other. (The group escapes me at the moment but maybe they where polyps). So specie A could breed with B, B with C, C with D and D with A. But D could not with B and so on.