In addition to one of the two species of Trichopolydesmidae hitherto recorded from Cameroon, Polydesmus integratus Porat, 1894, which is revised based on type material and shown to represent the genus Hemisphaeroparia Schubart, 1955, comb. n., 12 new species from the same genus are described from that country: H. zamakoe sp. n., H. bangoulap sp. n., H. spiniger sp. n., H. ongot sp. n., H. digitifer sp. n., H. parva sp. n., H. fusca sp. n., H. bonakanda sp. n., H. bamboutos sp. n., H. subfalcata sp. n., H. falcata sp. n. and H. mouanko sp. n. A key to all 13 species (of Hemisphaeroparia) known to occur in Cameroon is presented, and their distributions are mapped. All ten recognizable (but excluding two dubious) Afrotropical genera or subgenera of Trichopolydesmidae are rediagnosed and reclassified, based both on their type species and a presumed scenario of gonopodal evolution. As a result, the number of accepted genera is reduced to five: Sphaeroparia Attems, 1909 (= Megaloparia Brolemann, 1920), Physetoparia Brolemann, 1920 (= Elgonicola Attems, 1939, syn. n., = Mabocus Chamberlin, 1951, syn. n., = Heterosphaeroparia Schubart, 1955, syn. n.}, Eburodesmus Schubart, 1955, Mecistoparia Brolemann, 1926 (= Dendrobrachypus Verhoeff, 1941, syn. n.), and Hemisphaeroparia.