Abstract
In this work Tamsiella amazonica nov. sp. a new species of Nayades of the genus
Tamsiella HAAS, belonging to the Juruá River, an affluent of the Solimões River,
between Taumaturgo and Fóz do Bréu, Brazil, is described.
At the same time an analysis and new regrouping of the existing genera of
Monocondylaeinae, is made, giving some considerations about the geographical distribution of its genera in South American waters and its probable phyletic relationship.