1920] 8etchell-Crardner : Chlorophyceae 209 



1. Cladophora amphibia Collins 



Basal layer of densely branching, prostrate filaments, segments 

 cylindrical, 40-70ju, diam. and 2-5 diam. long, or fusiform, 1-2 diam. 

 long, swollen to IOO/a in the middle, emitting erect filaments with 

 segments 30-50ju, diam., 4-8 diam. long, cylindrical or irregular, term- 

 inal segments obtuse or truncate ; slender descending rhizoids some- 

 times issuing from lower segments of erect filaments. 



Growing on the ground among Salicornm and other salt marsh 

 plants along high-tide line. Known only from a single locality, viz., 

 Alameda, along the shores of San Francisco Bay, California. 



Collins, in Collins, Ilolden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 1284 (nonien nudum), and in Rhodora, vol. 9, 1907, 

 p. 200 (description), Green Alg. N. A., 1909, p. 349. 



Collins has correctly described this species as a "dull green 

 unattractive plant." It is not readily mistaken for any other, both 

 as regards its habitat and its habit. It is low and forms extended 

 patches along the salt marsh covering of Salicornia. Its discovery 

 in similar localities along the coast is to be expected. The species 

 would ordinarily be grouped with those of the Aegagropila section ; 

 it is matted together below by the intertwining of the prostrate fila- 

 ments and by the descending slender almost rhizoidal branchlets. 

 The branching is irregularly alternate and not at all dichotomous. 

 The turflike layer is not over a centimeter in thickness. 



2. Cladophora hemisphaerica Gardner 



Plants at first compact, hemispherical, of not over 1 cm. radius, 

 profusely branching at the base, dichotomous, forkings narrow, seg- 

 ments 60-150/1, diam., 3-6 diam. long, often distinctly clavate; later 

 less regularly hemispherical, up to 3 cm. or more radius, branches 

 more distant, with segments in the upper part 50-80ju, diam., cylin- 

 drical ; numerous slender tufts, up to 1 dm. long, on nearing maturity 

 arise from the hemispherical mass, having cylindrical segments 50-80/i, 

 diam., with forkings very distant and narrow; substance firm, not 

 adhering well to paper. 



Growing in small, shallow pools on rocks in the upper littoral belt. 

 Cypress Point, Monterey County, California. 



Gardner, m Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 2240 (nomen nudum), in Collins, Green Alg. Suppl. II, 

 1918, p. 83 (descr.). -^T'' 





