Collins, Holden & Setchell, Phycoth. Bor.-Amer.
Collins, F.S.; Holden, I.; Setchell, W.A. [1-2300]

Brown University - Algae
Catalog #: ABRU00003698
E. Butler s.n.
Phormidium tenue (C.Agardh ex Gomont) Anagnostidis & Komárek
Canada, Alberta, Hot Sulphur Springs, Banff, Canada

Michigan State University Algae
Catalog #: MSC0183263
E. Butler #s.n. 00 June 1901
Leptolyngbya tenuis (Gomont) Anagnostidis & Komárek
Canada, Alberta, Hot Sulphur Springs, Banff

Miami University - Algae
Catalog #: 000187981
E. Butler #s.n. 00 June 1901
Phormidium tenue (C.Agardh ex Gomont) Anagnostidis & Komárek
Canada, Alberta, Hot Sulphur Springs, Banff

Yale University Herbarium
Catalog #: YU.092088
Eloise Butler s.n.
Phormidium tenue (C.Agardh ex Gomont) Anagnostidis & Komárek
Canada, Alberta, Hot Sulphur Springs, Banff