244 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



Sargassum acinacifolium S. & G. 



Plate 37, Figs. 1-26 



Setch. & Gard., 1924, p. 724, pi. 21, fig. 82. 



Basal parts not positively known, probably a parenchymatous disk- 

 holdfast; branches terete, smooth, deliquescent above; leaves 12-16 mm. 

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

 margin and apex coarsely dentate, ecostate, cryptostomata absent; ves- 

 icles subspherical to ellipsoidal, smooth, with a simple apicula about 

 0.6 as long as the bladder, commonly unflattened, on pedicels shorter than 

 the diameter; oogonial receptacles 2 to 3 times forked, nearly cylindrical, 

 smooth, or more or less denticulate toward the apices. 



J. 75, high sublittoral rocks, San Francisquito Bay, June; Brand. 2, 

 Guaymas?; MacDougal, Port Libertad, Sonora, May 4, 1923; D. 678, 

 lower littoral on cobblestone beach, south shore of Tiburon Island, July 

 (young specimens but apparently with the juvenile characters of this 

 species). 



Sargassum asymmetricum sp. nov. 

 Plate 36, Figs. 8-18 



Frondes axi primaria curta (1 cm. longa) gracilique, a rhizomatibus crassis 

 discum efficientibus oriente; ramis primariis teretibus, levibus, strictis, percurrenti- 

 bus, minime 6 dm. longis; foliis ecostatis, plerumque valde asymmetricis, dentatis, 

 2-2.5 cm. longis, infernis parvissirais, 3-6 mm. longis; cryptostomatibus inconspic- 

 uis; vesiculis ellipsoideis, cum extensionibus foliaceis dentatisque, 1-3-plo longi- 

 oribus coronatis. 



Primary axial stems terete, smooth, strict, percurrent, unbranched to 

 at least 6 dm., from a slender stipe 1 cm. long, attached to a small, knotty 

 disk of short, thick rhizomes, 1-1.5 cm. across; leaves ecostate, usually 

 strongly asymmetrical by means of a smooth, concave upper side, dentate 

 or almost lobed at times, 2-2.5 cm. long, the lowermost very small, 3-6 

 mm., blunt-lanceolate to almost triangular in shape; cryptostomata small, 

 inconspicuous, but present; vesicles ellipsoidal with usually dentate, foli- 

 aceous extensions, 1-3 times as long as bladder; antheridial inflorescences 

 about 1 cm. long, more or less heteroclyte, of 2-4 times branched recep- 

 tacles which are terminally dentate ; oogonial receptacles unknown. 



Type: D. 156, on rocks in lower littoral, Tiburon Island (opposite 

 Turner's Island), Jan. 25, 1940. Herb. AHF no. 13. 



D. 221, on rocky shore, Puerto Refugio, Jan.; D. 314, rocky shore, 

 Gonzaga Bay, Feb. (juvenile specimens) ; Poindexter, Punta Pefiasco, 

 March. 



