Phycoboca Boreali-Americana

Collins, Holden & Setchell.

1710. Phormidium Retzii Gomont.

Gomont, Monogr. des Oscill., p. 195, Pl. V, figs. 13-13, 1893.

Forti, Syll. Myx., p. 241, 1907.

Tilden, Minn. Algae, Vol. I, p. 105, 1910.

Forming sheaths on stalks of plants in shallow water. Great Pond, Eastham, Massachusetts, Sept. 9, 1910.

F. S. COLLINS