113 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.12 



upper more markedly dentate and more forked. The teeth were on the 

 whole rather coarser on most specimens than those on the type. The ves- 

 icle stalks were cylindrical at the base but above were more or less flat, or 

 even subfoliaceous and dentate, as occasionally happened in no. 34-254. 

 The few vesicles on the type material kindly loaned by the California 

 Academy of Sciences showed a range of form, some with a flattened stalk 

 but more, apparently, without any flattening, and only two showed small 

 apiculi. Since the type consisted of fragments much worn and supporting 

 many attached organisms, the present collections probably more justly 

 express the natural variation of the species. The duplicate material loaned 

 with the type showed generally simple leaves rather finely serrate near 

 their bases, and generally loose receptacles. 



Ecuador: Archipielago de Colon, attached to rocks at Black Beach 

 Anchorage, I. Santa Maria, no. 34-254, 17 Jan. 1934. Ibid., drifted 

 onto I. Bartolome, I. San Salvador, no. 34-350B, 23 Jan. 1934. 



Sargassum albemarlense n. sp.'^^ 

 Plate 27 



Plants 4 dm tall or more, bushy, the main axes smooth, early defoliate, 

 bearing numerous lateral branches 10-15 cm long; leaves not crowded, 

 moderately thin, glaucus, 25-45 mm long, 4-7 mm wide, oblong to linear- 

 oblong, acute and a little asymmetrical at the base, the margins entire to 

 slightly erose sinuate, slightly tapered to the broadly obtuse apex ; midrib 

 evident in the lower half of the leaf, becoming indefinite and ending well 

 below the apex ; cryptostomata none or rare, inconspicuous ; vesicles mod- 

 erately numerous, spherical, smooth, 3-4 mm diam., pedicellate, the stalks 

 4-6 mm long, compressed and alate above, the wings sometimes extending 

 as ridges onto the lower sides of the vesicles ; receptacles at first subtended 

 by ordinary foliage leaves, later these drop, but 1-4 quite small leaves may 

 develop among the branches of the receptacles, which are moderately 

 compact, 5-8 mm long and nearly as wide, dichotomous to alternately 

 branched, the divisions erect or moderately divergent, smooth, the final 

 divisions short and close, with acute apices. 



These plants are distinguished from S. zacae Setchell & Gardner 

 (1937, p. 138, pi. 29, figs. 13, 14, pi. 31, fig. 50) by the lack of any 



78 Sargassum albemarlense n. sp. — Plantae ad 4 dm altitudine, fruticosae, 

 stipitibus levibus, foliis paululum sparsis, tenuibus, glaucis, lineari-oblongis, basi 

 acuta atque asymmetrica, marginibus paululum eroso-sinuatis, cacumine late ob- 

 tuso; costa non ad apicem folii attingente; cryptostomatibus nullis aut raris, in- 

 conspicuis; vesiculis spbaeroideis, 3-4 mm diam., in stipitibus compressis saepeque 

 alatis, longioribus dimidio; receptaculis compactis, divisionibus brevibus levibus- 

 que. Planta typica in loco dicto Pta. Albemarle, I. Isabela, Ecuador, legit W. R. 

 Taylor no. 34-105, 12 Jan. 1934. 



