Resumo Continuação do levantamento qualitativo das algas desmídias, Mesotaeniaceae e Desmidiaceae, dos lagos Cristalino e São Sebastião, Estado do Amazonas, Brasil. As amostras examinadas foram coletadas no período de fevereiro de 1977 a janeiro de 1978. São descritos, com detalhes morfológicos, 11 taxons infragenéricos, representantes dos gêneros Netrium, Closterium e Pleurotaenium. A descrição de cada espécie, variedade ou forma taxonômica é complementada com desenhos, medidas, distribuição geográfica no Brasil e comentários.

Summary This paper is a contribution to the qualitative survey of the desmids — Mesotaeniaceae and Desmidiaceae, Zygnemaphyceae — from two lakes, Lago Cristalino and Lago São Sebastião in the northern State of Amazonas. Brazil. Samples were galhered monthly during one year. The genera Netrium, Closterium and Pleurotaenium were identified to totaling 11 infrageneric taxa, all of which were described in every morphological detail possible. They were also given measurements and the illustrations needed for the taxonomic identification. Comments about every named taxon are included. An artificial key based on fundamental morphological and vegetative characteristics was prepared for the identifications of the taxa documented in the text. A larger number of desmid taxa were observed to occur in Lago Cristalino than in Lago São Sebastião. The taxon commonly occuring in both lakes was Clasterium lirteatum var. lineatum f. lineatum.

Resumo O presente trabalho é uma contribuição ao levantamento qualitativo das algas desmídias filamentosas dos lagos Cristalino e São Sebastião, Estado do Amazonas, Brasil. Foram realizadas coletas mensais durante um ano, entre fevereiro de 1977 e janeiro de 1978. O material identificado, num total de 13 táxons infragenéricos, é descrito com detalhes morfológicos. Encontraram-se representantes dos gêneros: Bambusina, Desmidium, Groenbladia, Hyalotheca, Sphaerozosma e Spondylosium. As espécies de Bambusina e Groenbladia só ocorreram no lago Cristalino.

Summary This paper is a contribuition to the qualitative survey of the filamentous desmids from two lakes, lago Cristalino and lago São Sebastião in the northern State of Amazonas, Brasil. Samples were gathered montnly during one year. The material collected was identified to totaling 13 infrageneric taxa, all of which were described in every morphological detail possible. They were also given measurements and the illustrations needed for the taxonomic identification of each of the 13 taxa. Comments about every named taxon are included. An artificial key based on fundamental morphological and vegetative characteristics was prepared for the identifications of the genera, species, varieties, and named taxonomic formae documented in the text. One map and one plate containing 18 figures complement the text. A larger number of desmid genera were observed to occur in lago Cristalino than in lago São Sebastião. The genera commonly occuring in both lakes were: Desmidium, Hyalotheca, Sphaerozosma and Spondylosium. The genera Bambusina and Groenbladia only occurred in lago Cristalino.

Resumo Registro da ocorrência de lóricas de Trachclomonas playfairi Defl., espécie de Euglenophyceae, em amostras de sedimentos do lago Aningal, Boa Vista, Território Federal de Roraima, norte do Brasil. O material encontrado é descrito em detalhes e ilustrado.

Summary In this paper loricas of Trachelomonas playfairi Defl., Euglenophyceae, are recorded from sediment sample from lago Aningal, Boa Vista. Território Federal de Roraima, northern Brazil. The material found is described in detail and illustrated.