1 AET. 12. — K. YEXDO. 



and Harvey.^^ In his classical work "Species Sargassorum 

 Australiœ," J. Agaedh revised all the species of Sargassum 

 known from the Australian seas as well as those from the coast 

 of Japan and the Indian Ocean, adding at the same time, a large 

 number of new species described by him. He"' again revised 

 Sargassum of Japan in " Analecta Algol ogica " and added a few 

 other species. Before the last mentioned publication appeared 

 De Toni included all known species up to that time in his 

 " Sylloge Algarum." The Japanese forms mentioned in that 

 work numbered 39 species and 3 varieties inclusive of the doubtful 

 species described by the earlj'^ writers. Okamura's enumeration 

 noted above is based entirely upon De Toni's work. 



Any one who tries to touch upon the Sargassum and Cysto2^hyl- 

 liim of Japan encounters the utmost difficidty in identifying the 

 specimens with the descriptions. The plants under these genera 

 vary greatly in their morphological characters according to the 

 age of the individual and the conditions of its environment : 

 and not a few species have their uj)per parts so wliolly unlike 

 their lower portions, that it would be quite im2:)0ssible to imagine 

 the former in cases in which the latter alone were given. Many 

 of the species assigned to the coast of Japan and established by 

 European botanists were based upon fragmentary and sterile 

 specimens of such variable plants as mentioned above found 

 floating on the sea or cast ashore. And moreover the species 

 described by Hatîvey and by J. Agaedh have never been 

 illustrated. The present writer could not restrain an exclamation 

 of impatience at a diagnosis of a few lines which was satisfactorily 



1) Cluiracters of New Alg;\i chielly from Japan anil adjacent Eegions collected bj' 

 Charles AVright in the North Tacific Expedition UIlde^ 'Captain Eodgkrs.— Proceedings 

 of the American Academy of Art and Science. Vol. V. 1859. p. 327-334. 



2) De Speciebiis Sargassorum .Taponicis Scholia. (Anal. Algol, cont. TIT. p. 49-()l). 



