In a revision of the genus Setaria s.l. the author gives a review of the literature on the systematics of this group. The genus Setaria s.l. is divided into three genera. Hyraconema n.g. monotypic for H. loveridgei (Sandground, 1928), a primitive worm of the hyracoids; Setaria Viborg, 1795, monotypic for S. equina (Abildg., 1789) the common parasite of equine animals; and Artionema n.g. for the remaining species, all of which occur in artiodactyls. Artionema africana n.sp. is the genotype. A. africana is found in Tragelaphus spp. and cattle in various parts of continental Africa. The other new species A. hartwichi n.sp. is found in the European deer, Capreolus and Alces on continental Europe. The paper includes a discussion on host parasite relationship, phylogeny and the evolution of taxonomic characters in speciation. In the Subfamily Setariinae Yorke and Maplestone, 1926, the author recognizes five genera as follows: Skrjabinofilaria Trav., 1925; Hyraconema gen. nov., Setaria Viborg, 1795, Papillosetaria Vevers, 1923 and Artionema gen. nov. The paper ends with a host list.