71-1 University of California Piiblications in Botany [Vol. 8 



and of the main stipe, which are in many instances of much value in 

 classification, cannot be stated. We have several clean primary 

 branches which are in good fruiting condition and otherwise seem- 

 ingly characteristic. The loose, open character of the branching and 

 the shape and size of the vesicles remind one very much of some mem- 

 bers of the genus Cystophyllum J. Ag. It has perhaps its nearest 

 relative in 8. carpophyllum but differs in leaf characters and in the 

 vesicles being regularly lateral or terminal to the receptacles. 



4. Sargassum lapazeanum S. and G. 



Fronds 4.5-6 dm. high, arising from a solid parenchymatous disk ; 

 stipe 1.5 cm. long; primary branches 5-7, terete, smooth, giving rise 

 to numerous long, slender, secondary branches ; leaves 0.5-1.5 cm. 

 long, asjmimetrical, widest toward the apices, with very short petioles, 

 the basal half of the upper margin smooth and concave, the remainder 

 of the blade sharply dentate, midrib inconspicuous, cryptostomata 

 abundant and conspicuous ; vesicles scattered among the receptacles, 

 ellipsoidal, 1-2 mm. long, transformed from the base of a leaf, mostly 

 crowned by the remnants of the blade ; receptacles 4-7 mm. long, 2-3 

 times forked, branches strict, spinulose, intermixed with leaves and 

 receptacles forming a heteroclyte cyme. 



Cast ashore. La Paz, Lower California. 



Setchell and Gardner, Mar. Alg. Gulf Calif., 1924, p. 733, pi. 20, 

 fig. 74. 



^t5- 



5. Sargassum Bryantii S. and G. 



Basal parts unknown ; branches terete, more or less contorted ; 

 leaves 6-12 mm. long, 0.5 as broad as long, ecostate, asymmetrical, the 

 upper margin concave and smooth, the lower margin and the end 

 unevenly serrate ; cryptostomata few and irregularly placed ; vesicles 

 numerous along the ramuli or, more rarely, intermixed with the 

 receptacles, subspherical, marginate when young, spinose, short- petio- 

 late; receptacles short, 4-8 mm. long, 1.5-3 mm. broad, irregular 

 cylindrical below, blunt or pointed, at times slightly spinose and 

 crowned with a rudiment of a leaf. 



Cast ashore near La Paz, Lower California. 



Setchell and Gardner, Mar. Alg. Gulf Calif., 1924, p. 733, pi. 21, 

 fig. 83. 



The characters of the receptacles do not agree in every particular 

 with those given by J. Agardh (Sp. Sargas. Austral.) in his key to 



