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

Brown University - Algae
Catalog #: ABRU00003302
I. Holden s.n. 23 June 1893
Symploca thermalis Kützing ex Gomont
United States, New York, Schenectady, NY

Yale University Herbarium
Catalog #: YU.091735
Isaac Holden s.n. 23 June 1893
Symploca thermalis Kützing ex Gomont
United States, New York, Schenectady, NY

Michigan State University Algae
Catalog #: MSC0184972
Isaac Holden #s.n. 23 June 1893
Symploca thermalis Kützing ex Gomont
United States, New York, Schenectady, Schenectady

Miami University - Algae
Catalog #: 000187198
Isaac Holden #s.n. 23 June 1893
Symploca thermalis Kützing ex Gomont
United States, New York, Schenectady, Schenectady