The freshwater Bangia atropurpurea (Roth) Ag. and the marine B. fuscopurpurea (Dillw.) Lyngb. have both been studied in unialgal culture. They are morphologically similar and have been united by some authors under the former name, but a comparison of salinity ranges in cultures has shown that they differ, only showing optimum growth in freshwater and marine media respectively.
B. atropurpiirea has also been kept under observation in the field for three years and little seasonal periodicity has been noticed. In cultures of this species branched filaments and Conchocelis-stages have been obtained, both bearing monospores. These stages are described in detail.