Phycotheca Boreali-Americans

Collins, Holden & Setchell.

1734, Rhizoclonium riparium (Roth) Hary.

Harvey, Phyc. Brit., Pl. CCXXXVIII.

Collins, Green Algae of N. A., p. 328, 1900.

Floating in slightly brackish water, Berkeley, California, Oct.
15, 1903.

N. L. GARDNER.

Intermediate between the typical form and var. validum (Gobi)
Foslie.

1735, Rhizoclonium tortuosum Kuetz.
forma longiarticolatum Collins, n. f.

In tangled masses on various species of algae, Moss Beach, San
Mateo County, California, Dec., 1909.

N. L. GARDNER.

In Typical R. tortuosum the cells are pretty uniformly 2 diam.
long just before division, 1 dia. after. In this form none were ob-
served less than 2 diam., while cells up to 3 & 6 diam. long were not
uncommon.

F. S. C.