Two species of South American Mailed Catfishes of the genus Pseudoloricaria Bleeker, 1862 are redescribed and figured from type-specimens and additional material: Pseudoloricaria laeviuscula (Valenciennes, 1840), and Pseudoloricaria punctata (Regan, 1904). Since the provenance of the holotype of P. laeviuscula is unknown, the type-locality of this species is restricted to the mouth of the Rio Tapajós at Santarém. The lectotype is selected from the three syntypes of P. punctata, and its type-locality is restricted to the Rio Amazonas at Manaus. P. laeviuscula is distributed only in the Rio Amazonas basin in Brazil, whereas P. punctata occurs in several river systems, viz. the Rio Amazonas basin in Brazil, Peru, and Ecuador, in the Rio Parnaiba, Est. Piaui, Brazil, in the Essequibo River system in Guyana, and in the Rio Meta system in Colombia. Loricaria griseus Eigenmann, 1909, Rhineloricaria petleyi Fowler, 1940, and Loricariichthys parnahybae Fowler, 1941, are synonymized with Pseudoloricaria punctata for the first time.