a es Ға ER E DAMEN ава 
SARGASSUM 67 
15-35 mm. long, 6-10 mm. broad, mostly undulate-crisped, the 
margins sinuate-lobed, obscurely and irregularly or sometimes 
deeply dentate, or subentire, the short petiole often bearing 1-3 
tooth-like appendages, cryptostomata inconspicuous or almost 
wanting; vesicles small, ovoid, or obovoid, muticous, 3-5 mm. 
long, on pedicels of about equal length; receptacles cymose, 2-5 
times subdichotomous, 5-7 mm. long, congested in the axils of the 
leaves, the ultimate branchlets conic-cylindric or short-finger- 
shaped, 2-4 mm. long, often roughened by developing sporelings. 
In general habit, Sargassum pacificum somewhat resembles the 
West Indian 5. foliosissimum (Lamour.) Vickers (which is perhaps 
the oldest valid name for the rather indefinite thing currently 
known as Sargassum vulgare Ag., though Lamouroux's Fucus 
foliosissimus was published by illustrations rather than by diag- 
nosis). It differs, however, from the typical 5. foliosissimum in 
the almost complete absence of cryptostomata, the longer and 
commonly less dentate leaves, etc. 
Bory's type specimen of Sargassum pacificum was collected at 
Concepcion, Chile, in 1823, and is now preserved in the Muséum 
d'Histoire Naturelle in Paris; its leaves are 15-40 mm. long and 
4-8 mm. wide, the margins sinuate, subentire, ог sparingly dentate, 
the petioles sometimes bearing one or two teeth, the crypto- 
stomata almost wanting; vesicles subglobose or slightly obovoid, 
2-3 mm. long on stalks of equal length, mucronate when young 
but soon muticous; receptacles 3-5 times subdichotomous, con- 
gested in the axils of the leaves, the ultimate branchlets conic- 
cylindric or digitiform, 2-5 mm. long. 
PLATE 25. Sargassum pacificum 
Photograph of a lete fertil ecimen (from liquid preservative—Coker 270), 
> Y r ы 
reduced to a little less than опе half of the natural dimensions. 
“ Fucodium fastigiatus" is attributed to the coast of Ancón, 
Peru, by Piccone (Alg. Vettor Pisani 40. 1886). 
