The neotropical mailed catfishes of the genera Lamontichthys P. de Miranda Ribeiro, 1939 and Pterosturiosma n. gen., including the description of Lamontichthys stibaros n. sp. from Ecuador (Pisces, Siluriformes, Loricariidae)

Descriptions and illustrations are given of four species of mailed catfishes belonging to the subfamily Loricariinae, tribe Harttiini. Two species are assigned to Lamontichthys P. de Miranda Ribeiro, 1939: Lamontichthys filamentosus (La Monte, 1935) (type-species, of which Harttia filamentissima C. H. Eigenmann & Allen, 1942, is provisionally considered a junior synonym), based on a total of thirteen specimens, including all type-specimens, from Brazil, Bolivia, Peru, and Ecuador (all from tributaries of the Rio Amazonas system), and Lamontichthys stibaros n. sp., based on two specimens from Ecuador, sympatric with the former species. Harttia microps C. H. Eigenmann & Allen, 1942, is redescribed from three out of the five type-specimens, originating from Iquitos, Peru (Rio Amazonas system). It is designated as type-species of Pterosturisoma n. gen., which superficially resembles Lamontichthys. Sturisoma brevirostre (C. H. Eigenmann & R. S. Eigenmann, 1889), type-species of Parasturisoma A. de Miranda Ribeiro, 1911 ( = Sturisoma Swainson, 1838), which was poorly described previously, is redescribed from its unique holotype, primarily to indicate the generic distinction from both Lamontichthys and Pterosturisoma, the species of which have been recently referred to Parasturisoma.