The zodariine spider genus Mallinus Simon, 1893 is redescribed and diagnosed. The type species, M.nitidiventris Simon, 1893 from South Africa, was originally described from subadult specimens. Adults of both sexes of M.nitidiventris are described for the first time, based on recently collected material, and the genus is rediagnosed, redescribed, and its relationships discussed. A single aberrant male specimen from Namibia is here described as a morphospecies, as it is presumed to only be superficially related. A second species, M.defectus Strand, 1906 from Tunisia, is considered a 'species inquirenda', as the type specimens could not be traced, but this species is in any case unlikely to be congeneric. The genus is one of 10 cases of a monotypic genus in the Zodariidae. Notes are provided on the biology of M.nitidiventris.
Keywords: Zodariinae; Arid; Nama Karoo; South Africa; endemic; myrmecophagous.