The genus Centrorhynchus (Acanthocephala) in North America with description of Centrorhynchus robustus n. sp., redescription of Centrorhynchus conspectus, and a key to species.

Reexamination of the type series of Centrorhynchus wardae Holloway, 1958, and Centrorhynchus conspectus Van Cleave and Pratt, 1940, revealed no consistent difference between the 2 purported species; therefore, C. wardae is considered a junior synonym of C. conspectus. Specimens from additional collections are consistent with this view and provided adequate material for redescription of the species. Centrorhynchus robustus n. sp. resembles C. conspectus in the number of hooks per Salient differences between the 2 species are size and body shape, with C. robustus having a robust trunk with the widest diameter anteriad and C. conspectus being elongate with no region of the trunk consistently widest. Additionally, a conspicuous posteriad swelling exhibited by females of C. conspectus is lacking in C. robustus. Centrorhynchus kuntzi is reported for the first time from Montana and Nebraska, and C. conspectus is reported for the first time from an eastern screech owl, Otus asio.