This paper presents the morphological and/or structural and mensurable characteristics of 12 Eunotia species (E. batavica A. Berg, E. deficiens Metz., Lange-Bert. & García-Rodr., E. genuflexa Nörpel-Sch., E. hepaticola Lang-Bert. & Wydrz., E. herzogii Krasske, E. mucophila (Lange-Bert., Nörpel-Sch. & Alles) Lange-Bert., E. pileus Ehr., E. pirla Carter & Flower, E. schwabei Krasske, E. subarcuatoides Alles, Nörpel-Sch. & Lange-Bert., E. transfuga Metz. & Lange-Bert. and E. yanomami Metz. & Lange-Bert.) found in the Lagoa do Casamento and Butiazais de Tapes areas, between 30º10'-30º40'S and 50º30'-51º30'W, on the Rio Grande do Sul State Coastal Plain. Comments on distribution and habitats where the taxons are found are included.
diatom; distribution; taxonomy
