264 University of California Publications in Botamj [Vol.8 



2. Ulva californica Wille 



Frond 1.5-2 cm. long, up to 1.5 cm. wide, triangular or reniform 

 with wavy edge, sometimes with proliferations of a few cells each, 

 passing abruptly into a slender, filiform stipe ; cells of the stipe, which 

 on the inner side form rhizoidal prolongations, are in cross section 

 about quadrate; membrane 30-35ja thick; the cells in the upper part 

 of the frond are rather irregularly polygonal with rounded corners; 

 no noticeable arrangement in longitudinal series. 



Growing in profusion on rocks near high-tide line. California 

 (region about San Diego). 



Wille, in Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 611; Collins, Green Alg. N. A., 1909, p. 215. 



Our knowledge of TJlv<i caUfornica is derived from the type and 

 other specimens collected by Mrs. M. S. Snyder at La Jolla, near San 

 Diego, California. It seems to be a very small species with a compara- 

 tively long stipe and having the cells small and nearly isodiametric. 

 In this combination of characters it seems amply distinct from all other 

 species of the genus. 



3. Ulva angusta S. and G. 



Plate 22, and plate 26, fig. 1 



Frond simple or very rarely lobed, lanceolate to oblanceolate, 8-15 

 cm. long, 0.5-1.5 cm. wide, 35-45;u, thick (occasionally about 53;u.), 

 tapering either gradually or abruptly at the base to a delicate, solid 

 stipe with discoidal holdfast, color of fronds pale green, margins vary- 

 ing from almost plane to very much crisped; cells in surface view 

 3- 6-sided, with rounded angles, 5-12/i, diam.^in section, quadrate to 

 one and a half times longer than broad, with rounded angles; chro- 

 matophore filling the outer half of the cell. 



Growing in shallow pools along high-tide level. California (region 

 of San Francisco). 



Setchell and Gardner, Phyc. Cont. I, 1920, p. 283, pi. 27, and 

 pi. 31, fig. 1. 



We find at several places along the coast of central California, 

 a rather short-and narrow Ulva which does not seem to belong to any 

 of the hitherto described species. We have felt compelled, therefore, 

 to give it a name. It resembles the Phycoseris lapathifoUa of Kuetz- 

 ing (1856, pi. 25) but is shorter and narrower. It also resembles, 



