A Key to the American Species of Hydrocanthus Say, with Descriptions of New Taxa (Coleoptera: Noteridae)

The species of the genus Hydrocanthus (Say 1823) present a Gondwanan distribution with members in Africa, the Indo-Malayan region, Australia, and the Americas. The African species have been separated in the subgenus Sternocanthus Guignot, and the American species present two groups: Hydrocanthus sensu stricto with species ranging from Patagonia to Canada (type species H. iricolor Say) and Guignocanthus n. subg. (type species H. ancus Guignot) with species ranging from the Mato Grosso to Texas (described herein). The following new species are described: Hydrocanthus (s. str.) pallisteri (Central Plateau of Mexico), H. (s. str.) occidentalis (western Mexico), H. (Guignocanthus) guignoti (Mato Grosso, Brasil). H. (s. str.) atripennis Say is considered to be the same as H. texanus Sharp.