ABSTRACT: A diverse radiolarian fauna is described from strata of a road cut section of the uppermost part of the Bell Canyon Formation (Capitanian, Guadalupian, Middle Permian), Apache Mountains, West Texas. Fifteen new species are described: Campanulithus insuetus, Pseudoalbaillella apachensis, Astroentactinia capitanensis, Polyedroentactinia guadalupensis, Afanasievella apachensis, Copicyntra erinacea, Paracopicyntra snyderi, Klaengspongus planus, Copiellintra orbiculata, C. fastuosa, Shangella capitanensis, Rectotormentum wardlawi, Tetratormentum ormistoni, Quadrilobata? blomei, and Nazarovispongus globosum. The diagnoses of the species Follicucullus sphaericus Takemura in Takemura et al. 1999 and the genus Raciditor Sugiyama 2000 are emended. The rank of the subspecies Raphidociclicus gemellus americanus Nazarov and Ormiston 1985a is raised to species level. The genus Nazarovispongus Kozur 1980 is considered to be a valid genus and is reinstated. Established are one new genus, Afanasievella (assigned to the family Spongentactiniidae), one new subfamily Polyedroentactiniinae (in the composition of the family Orosphaeridae), and one new family Tetratormentidae (in the composition of the order Pyramidata). The radiolarian assemblage from the described section in the Apache Mountains is at least partly coeval with the radiolarian assemblage from the Reef Trail Member of the Bell Canyon Formation in the Guadalupe Mountains, allowing a straight correlation of this age strata between the Apache and Guadalupe mountains. This correlation is supported by the conodont species that define the latest Guadalupian conodont zones and that occur together with radiolarians in both areas. The radiolarian species Albaillella yamakitai in sense of Xia et al. (2005) present in the late Guadalupian J. altudaensis conodont Zone cannot be a marker for the Guadalupian – Lopingian boundary as was proposed by Xia et al. (2005).