A taxonomic revision of South American species of the genusStenostomumO. Schmidt (Platyhelminthes: Catenulida) based on morphological characters.

This paper revises the genusStenostomumbased on a rich collection of species from Argentina and on a review of bibliographical resources of all known South American species. The description of South American species is standardized. The new genusAnokkostenostomumis established and several species ofStenostomumare transferred to it based on the absence of light-refracting bodies and the presence of a metameric anterior brain lobe. We report fiveStenostomumspecies and threeAnokkostenostomumspecies new to Argentina and present an identification key for South American species. Finally, all the world species are compiled, with an overview of their distribution. © 2005 The Linnean Society of London,Zoological Journal of the Linnean Society, 2005,144, 37–58. [ABSTRACT FROM AUTHOR]