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

University of North Carolina at Chapel Hill Herbarium; Max & Fran Hommersand Algae Herbarium: Algae
Catalog #: NCU-A-0018311
Farlow, W. G. #P.B.-A. 1163 00 September 1903
Lyngbya subtilis Holden
United States, Massachusetts, Essex, Magnolia; Magnolia, Massachusetts

Field Museum of Natural History
Catalog #: C0500270F
I. Holden #s.n. 00 April 1904
Lyngbya subtilis Holden
United States, Massachusetts, Essex, Magnolia

Michigan State University Algae
Catalog #: MSC0184002
Isaac Holden #s.n. 00 September 1903
Phormidium holdenii (Forti) L.H.Z.Branco, C.L.Sant'Anna, M.T.P.Azevedo & L.Sormus
United States, Massachusetts, Essex, Magnolia, Massachusetts

Miami University - Algae
Catalog #: 000188157
Isaac Holden #s.n. 00 September 1903
Phormidium holdenii (Forti) L.H.Z.Branco, C.L.Sant'Anna, M.T.P.Azevedo & L.Sormus
United States, Massachusetts, Essex, Magnolia, Massachusetts

Brown University - Algae
Catalog #: ABRU00003877
W. G. Farlow s.n.
Lyngbya subtilis Holden
United States, Massachusetts, Magnolia, MA

Yale University Herbarium
Catalog #: YU.092246
William Gilson Farlow s.n.
Lyngbya subtilis Holden
United States, Massachusetts, Essex, Gloucester; Magnolia, MA