Redescription of Ilyocryptus tuberculatus Brehm, 1913 (Anomopoda, Branchiopoda)

The morphology of Ilyocryptus tuberculatus Brehm, 1913 is redescribed, base d on material from the Niger basin, Africa. The species name was given by B rehm erroneously, because under an optical microscope he mistook internal s tructures (the columns between the outer and inner walls of the valves) for the tubercules on the valve surface. But this species is undoubtedly valid , and 'incorrect' species names must be conserved. Differences between I. t uberculatus and the most similar I. agilis (probably absent from the majori ty of African waters), I. spinifer (common in Africa), and some other speci es are discussed. Currently, I. tuberculatus is known for the Central Afric an Republic, Mali and Niger.