Bocchino (1964) described and figured a new genus and species, Propygidium primaevus, and assigned it to the siluriform family Trichomycteridae (=Pygidiidae). After examination of the holotype, the only referred specimen, the authors conclude that it does not correspond to a catfish, but to an acanthopterygian. Since it was considered the only fossil record of trichomycteridae, and having been used to support speculations on the “center of origin” of this Neotropical family (see Ringuelet, 1975), it is appropriate to correct the former assignment.