Examination of the relevant types and other material of species of Oosternum Sharp and Paroosternum Scott has proven it necessary to establish the following taxonomic changes: The genus Pemelus Horn, 1890 is considered a junior synonym of Oosternum Sharp, 1882. Cercyon sorex Sharp, 1874, currently placed in Oosternum, is transferred to Paroosternum. The following new specific synonymies are established (senior synonym given first): Paroosternum degayanum Scott, 1913 = Oosternum ecarinatum Orchymont, 1942; Cercyon sorex Sharp, 1874 [now Paroosternum s.] = Oosternum horni Orchymont, 1914. Oosternum sharpi nom. n. is proposed as a new replacement name for Oosternum costatum Sharp, 1882 nec (Le-Conte, 1855).