Three species of two-clawed Mallophaga have heretofore been recorded from South American mammals. Concerning one of these species, Menopon extraneum Piaget, nothing is known aside from the information included in the original description and, judging from this and the accompanying figure, it appears not to differ from the usual type of bird-infesting members of this group. The other two species have each been made the type of a genus and these two genera have been considered by Harrison as representing a well-marked family, the Trimenoponidae.