I9i2") i Setchell-Gardncr: Melanophyceae 713 



Anderson and Eaton, Alg. Exsicc. Amer. Bor., no. 102; Collins. Ilolden 

 and Setchell. Phyc. Bor.-Amer. (Exsicc), no. 537a (not 537&). Not 

 C. Agardh, Sp. I, 1820, p. 27. Not Yendo. Fucaceae Japan, 1907, 

 p. 54. Not Fwcus pilwlifer Turner, Fuci, vol. 1, 1808, p. 145, pi. 65. 

 Sargassum dissect if oJium Setchell and Gardner, in Gardner, New Pac. 

 Coast Mar. Alg. I, 1917, p. 386. 



2. Sargassum acinacifolium S. and G. 



Basal parts unknown ; branches terete, smooth; leaves 12-16 mm. 

 long, asymmetrical, the upper margin concave and smooth, the lower 

 margin and apex coarsely dentate, ecostate, cryptostomata absent ; 

 vesicles situated at the base of the receptacles or more rarely among 

 the receptacles, subspherical, smooth, apiculate, 1.5-2.5 mm. diam., on 

 pedicels shorter than the diameter ; receptacles 2-3 times forked, 

 nearly cylindrical, not spiny, acuminate, more or less denticulate 

 toward the apices. 



Cast ashore, Guaymas ( ?), Mexico. 



Setchell and Gardner, Mar. Alg. Gulf Calif., 1924, p. 732, pi. 21, 

 fig. 82. 



This species of Sargassum is a near relative, apparently, of S. 

 lapazeanum and of S. Bryantii, but it differs sufficiently in leaf, 

 bladder, and receptacle characters to warrant giving it separate 

 characterization. 



3. Sargassum guardiense S. and G. 



Basal parts unknown ; primary branches up to 5 dm. high ; second- 

 ary branches long and slender ; branches and ramuli all smooth, terete ; 

 leaves slightly flattened, to filiform, ecostate, margins smooth, crypto- 

 stomata absent or rare ; vesicles situated at the base of the fructiferous 

 ramuli or among the branches of the receptacles, subspherical to 

 slightly cylindrical, 2-4 mm. long, smooth, tapering at both ends, 

 apiculate, on pedicels shorter than the diameter ; receptacles 1-3 times 

 forked, terete, not spinose, 5-8 mm. long, forming with the vesicles 

 short heteroclyte cymes. 



Cast ashore at Angel de la Guardia Island, Gulf of California. 



Setchell and Gardner, Mar. Alg. Gulf Calif., 1924, p. 732, pi. 19, 

 fig. 64. 



Unfortunately we have no complete specimens of this seemingly 

 very well defined species of Sargassum. The character of the holdfast 



