Phormidium amoenum Kützing, 1843b: 192 (lectotype locality: Padova, Italy fide Drouet, 1968: 231).
Oscillatoria amoena (Kützing) Gomont, 1892b: 225.—Islam, 1974a: 21–22, pl. 8: figs. 7–11.— Islam, 1974b: 89.— Islam, 1976: 70, pl. 72: fig. 409.
INDIAN OCEAN DISTRIBUTION: Bangladesh.
Note: Drouet (1968: 230–231, 248) chose a specimen in L as the lectotype of this species and assigned it to Microcoleus vaginatus (Vaucher) Gomont.