The Nearctic species, as well as several Palearctic species, of Athous Eschscholtz, Harminius Fairmaire, Hemicrepidius Germar, and Acanthathous Champion are studied and rearranged with the following new combinations: the Nearctic Hemicrepidius simplex (LeConte), H. falli (Reitter), and H. palpalis (Fall) (each from Athous); the Palearctic Hemicrepidius hirtus (Herbst) and H. niger (Linnaeus) (each from Athous); Hemicrepidius dauricus (Mannerheim) and H. flavipennis (Cherepanov) (each from Harminius); Hemicrepidius inornatus (Lewis) (from Yukara); and Acanthathous photinoides (Champion), A. campanulatus (Champion), A. mexicanus (Candèze), A. aequinoctialis (Champion), A. marcidus (Champion), A. aztecus (Champion), A. rugipennis (Champion), A. angusticollis (Champion), A. carinicollis (Champion), and A. championi (Schwarz) (each from Athous). Hemicrepidius hirtus (Candèze) (nee hirtus Herbst) is renamed californicus, new name, and the name H. hemipodus (Say) is recognized rather than decoloratus (Say). Pertinent generic characters are illustrated and brief notes are given for each of the above species (except those in Acanthathous) and for Harminius (Diacanthous) triundulatus (Mannerheim), H. (D.) undulatus (DeGeer), and Hemicrepidius pallidipennis (Mannerheim). Renter’s two subgenera of Harminius: Diacanthous and Megathous are recognized. A key to the genera associated with Athous and to the subgenera of Harminius is provided.