Phylogenetic Relationships of African Killifishes in the Genera Aphyosemion and Fundulopanchax Inferred from Mitochondrial DNA Sequences is published by William J. Murphy, Thuan N. P. Nguyen, Eric B. Taylor and Glen E. Collier in Molecular Phylogenetics and Evolution Volume 11, Issue 3, April 1999, Pages 351-360.

Preliminary results indicate that BAT "Fundulopanchax kunzi" (batesigroup; subgenus Raddaella) belongs in the genus Aphyosemion not in Fundulopanchax.

It goes something like this: there is no kunzi, it's really splendidum. But there is no splendidum either they're all batesii. Either way we're talking about the same fish the nearly impossible to spawn genetically primatimve and probably founder species of Aphyosemion.

In other words it's a big old Aphyosemion rather than a Fundulopanachax where it was thought to belong.

While not free, the article can be found here: http://dx.doi.org/10.1006/mpev.1998.0566