vol.i] SetcJiell— Gardner. — Algm .of Northwestern America. 273 



Stipe 16-60 em. in length, cylindrical or nearly so only 

 at the very base, mueh flattened above, slender and flexible; 

 Rhachis more or less elongated, flattened, with the sporophylls 

 at first remote, later crowded. Sporophylls from narrowly to 

 broadly lanceolate and cuneate at the base, varying to broadly 

 ovate or oblong and distinctly cordate at the base, with more or 

 less pronounced stipes^ Blade elongated, 100-150 cm. long, 10— 

 35 cm. wide, broadly cuneate at the base, very thin, collapsing 

 when withdrawn from the water, with plentiful cryptostomata of 

 small size, Midrib narrow to fairly broad, oblong in cross sec- 

 tion. 



Xot uncommon from Unalaska to Paget Sound. 



The description applies to the species, in general, which is 

 better understood if divided into at least two forms, as has been 

 done below. The species is to be distinguished by its very 

 decidedly flattened stipe and thin blade. Specimens from several 

 localities were submitted to Kjellman, who replied that he con- 

 sidered it to be a distinct species belonging either to the group 

 represented by A. dolicJiorhachis-oblonga-elliptica of Kjellman or 

 by A. membranacea-Pylaii-grandifolia of J. G. Agardh. 



We supposed at first that some, at least, of our specimens 

 might represent forms of A. grandifola. This is particularly to 

 be suspected as to the broader forms, whde the narrower forms 

 approach ^-L. Pylaii and resemble also A. fragilis of Saunders. 

 From both of the latter, our plants differ, as far as descriptions 

 go. by the flattened stipe. 



Alaria tenuifolia f . typica Setchell f.-nov. Plate 22. 



The type of the species is No. 3286a of Setchell and Lawson's 

 collection on the west shore of Amaknak Island, Bay of Una- 

 laska. Alaska, where the species formed a distinct zone on rocky 

 shores below that of A. lanceolata and just above or just below 

 the limits of extreme low water. The stipe is of moderate length, 

 varying from 10 to 15 cm. as a rule,' while the blade is compara- 

 tively narrow, 8-15 cm. in width, and cuneate at the base, The 

 sporophylls are narrowly to broadly lanceolate with cuneate base 

 and short stalks. The midrib is not noticeably broad. 



On rocks and stones at low water mark. Amaknak Island, 



