[A new species of Euglena (Euglenozoa: Euglenales) isolated from extreme environments in "boiling mudflats" of Rincón de la Vieja volcano, Costa Rica].

A new species of euglena isolated from a hot and acid mud pool located in Las Pailas de Barro, Volcán Rincón de la Vieja, Costa Rica is described. This species inhabits hot and acid environments. Euglena pailasensis sp.