Two new species and a new genus of neotropical mailed catfishes of the subfamily Loricariinae Swainson, 1838 (Pisces, Siluriformes, Loricariidae)

A new monotypic genus and two new species of South American mailed catfishes of the subfamily Loricariinae are described and figured. A discussion of and comparative notes on related taxa are added. Ricola genus novum is established for the species originally described by Regan (1904) as Loricaria (Loricaria) macrops. A lectotype for Ricola macrops is selected from the two syntypes, originating from Río de la Plata in Argentina/Uruguay. Ricola macrops is compared with species of the genus Loricaria Linnaeus, 1758. Loricaria prolixa species nova is described from Rio Piracicaba, Est. São Paulo, Brazil. It is compared with Loricaria macrodon Kner, 1854, and with Loricaria lata C. H. Eigenmann & R. S. Eigenmann, 1889. Pseudohemiodon apithanos species nova is a species which displays remarkable colour polymorphism. It was previously recorded by Saul (1975) as Loricaria cf. laticeps from Río Conejo, Ecuador. The new species certainly appears most closely related to Pseudohemiodon laticeps (Regan, 1904).