Abstract
Species of the genera of the Cryptopygus complex in South Africa are morphologically revised. Five new species of the genus Cryptopygus Willem, 1902 s. s. and one new species of the genus Isotominella Delamare Deboutteville, 1948 are described. Cryptopygus abulbus sp. nov. and C. bulbus sp. nov. have only one chaeta on the anterior side of dens and no chaetae on the anterior side of manubrium, the latter species being characterized by the presence of a bulb at apex of antennae; C. inflatus sp. nov. shows a rare combination of eight ocelli on each side of the head with a tridentate mucro; C. longisensillus sp. nov. has five long s-chaetae on the fifth abdominal segment; C. postantennalis sp. nov. is unique by having a very long and slender postantennal organ with strong inner denticles; Isotominella laterochaeta sp. nov. is the second member of the genus and differs from the type species by many more anterior chaetae on the manubrium and the presence of chaetae on ventral side of metathorax. The genera are discussed and a key to all species of the Cryptopygus complex recorded in South Africa is given. The focus is on the Western Cape Province where the complex is the most diverse and sampling more complete than in other provinces of South Africa.