Vol. 1] Setchell-Ganlner. — Algce of Northtvestern America. 281 



plants of the precediug form which represent the typical form, 

 are 30-45 cm. high and 6-10 mm wide. The narrowness of the 

 frond and the acute angles between the fairly regularly dichoto- 

 mous branches give it a very distinct appearance. It represents 

 a distinct transition from the preceding to the following. 



Fucus inflatus f. filiformis ((Tmelin) Setchell and (irardner 

 f. nov. 



This seems to be the F. filiformis of Gmelin, or at least what 

 has passed under that name on the coast of New England. The 

 plants are 8-10 cm., even at times 15 cm., high and seldom over 

 1-2 mm. wide. While the midrib is distinct in some plants or 

 in some parts of others, as a rule the main i)ortion of the frond 

 is reduced to the thickened midrib portion itself without alae. 

 The receptacles are fairly broad in proportion to the sterile 

 portion of the frond. 



On sand rocks, ui)i)erm()st litoral zone. Fairhaven, Wash., 

 X.L.G.\ 



An extreme form as regards the slender character of the frond, 

 and it also has a tendency to spread out and liecome more flabel- 

 late in its dichotomy. Somewhere under F. iiiffafiis is probably 

 to Ije referred the F. Miclonensis mentioned l)y J. G. Agardh 

 (1870a, p. 35) as occurring at Vancouver Island, B. C. 



Fucus evanescens Agardh. 



The type of the present species came from Kamtschatka and 

 the species itself is well developed in the region of the North 

 Pacific as well as in the North Atlantic. As a rule it is easily 

 recognized in its broader forms, by its habit, and by the 

 midi-ib vanishing below the tips of the branches. It approaches 

 in some of its forms to F. platycarpus Thuret, and one of us has 

 been inclined to refer some forms which had some indication of 

 a more pinnate method of branching to the latter species. It 

 seems best, however, to refer all the plants not distinctly belong- 

 ing to the preceding species to F. ci'dnesceiis. It is interesting 

 to note that Borgesen (1902, ]). 472) refers Thuret's species to 

 F. spiralis L. 



