Anabaina fragilis Meneghini, 1837: 8 (type locality: Euganean Hills, near Padova, Italy).
Phormidium fragile (Meneghini) Gomont in Bornet, 1891: 249.—T. Pillay, Vijayaraghavan, & Thakurta, 1962: 420.— Nizamuddin & Gessner, 1970: 8.— Patnaik, 1973: 62.— S. Dixit, 1980: 59.— Farghaly, 1980: 138.— Untawale, Dhargalkar, & Agadi, 1983: [41].— N. Anand & Venkatesan, 1985: 102, fig. 9.— Chennubhotla, Kaliaperumal, & Kalimuthu, 1987a: 110–111.— Anagnostidis & Komárek, 1988: 391.— G. Subramanian et al., 1989: 311, 313, 315, 317–320.— Thajuddin & G. Subramanian, 1992a: table III.
Spirocoleus fragilis (Meneghini) P. Silva.
INDIAN OCEAN DISTRIBUTION: India, Madagascar.
Note: Drouet (1968: 29, 72), after examining a representative of the type collection (in LD), assigned this species to Schizothrix calcicola (C. Agardh) Gomont.