280 Vnivcrsity of California Piihlications in Botany [Vol.8 



]. Gayella polyrhiza Rosenv. 



Frond at first a simple filament of a single series of disk-shaped 

 cells, 10-12/t diam., attached to the substratum by a rhizoidal pro- 

 jection from the lower cell ; later attached at various parts of the 

 filament by rhizoidal growths, one or two from a cell ; increasing in 

 diameter by growth and division of cells, up to lO/x diam. ; terete or 

 somewhat irregular in surface, but not flattened ; cells with parietal 

 chromatophore and one pyrenoid ; in the mature plant showing super- 

 ficially an arrangement in longitudinal and transverse lines; in cross 

 sections an arrangement by 2^—8-16, etc., in somewhat Gloeocupsa- 

 like form ; asexual reproduction by aplanospores, arranged in longi- 

 tudinal and horizontal series. 



Known onlv from th'e west shores of Amaknak Island, Alaska. 



Rosenvinge, Groenl. Havalg., 1893, p. 937, f. 45, 46 ; Collins, Green 

 Alg. N. A., 1909, p. 221; Setchell and Gardner, Alg. N.W. Amer., 

 1903, p. 217; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 

 no. 914. 



The specimens distributed under no. 914 of the Phycotheca Boreali- 

 Americana agree so closely in every way with the description and 

 figures of Rosenvinge that we feel justified in referring them to 

 Gayella polyrhiza. They were not associated with anything resembling 

 a true Prasiola. 



2. Gayella constricta S. and G. 



Plate 12, figs. 5-10 



Filaments small, dark green, somewhat tufted, 1-4 mm. high, 

 18-20/x diam. at the base, up to 175/a at the apex, cylindrical-clavate, 

 uncinate, constricted at frequent intervals, sparingly branched at the 

 base; cells disk-shaped, 10-15/x diam., at first in a single series through- 

 out, remaining so for some distance at the base, but dividing into 

 groups longitudinally in two or more planes above, increasing the 

 diameter of the filament and preserving its cylindrical form in general 

 through gradually becoming larger, the terminal group of cells having 

 the greatest diameter; at frequent intervals groups of 2-6 cells remain 

 undivided vertically, giving a constricted appearance to the mature 

 plants ; cell walls hyaline, homogeneous ; cross-walls very thin ; 

 chromatophore single, occupying nearly the entire cell ; pyrenoid 

 obscure. 



Growing in depressions and crevices in rock, above high-tide level, 

 kept moist bj^ dashing salt spray. Discovered at Tomales Point, Marin 



