1925] Setchell-Ganbier: Melanophjircae 679 



Growing- on rock ledges exposed to the action of the surf, in the 

 upper third of the littoral belt. Cape Arago, at the entrance to Coos 

 Bay, Oregon. 



Gardner, Genus Fucus, 1922, p. 28, pi. 21. 



This form grew in abundance in company with F. furcatus f. 

 angustus. The two groups of plants were, however, in slightly dififer- 

 ent altitudes in the belt, and were not indiscriminately intermixed. 

 When the two sets of plants are dried, they are easily distinguishable 

 by the smoothness of the segments, forma hesperius being smooth 

 and usually shining, while forma angustus is rough, due to caecosto- 

 mata, and is of a duller color. 



2. Fucus edentatus f. divergens Gardner 



Fronds coriaceous, smooth and glossy, 28-38 cm. high, regularly 

 dichotomous, dark olive green, black on drying ; segments divergent, 

 7-11 mm. (up to 15 mm.) wide, cuneate below, linear above, reduced 

 somewhat above each forking, terminal truncate, growing point incon- 

 spicuous, midrib very distinct, percurrent, cryptostomata and caeco- 

 stomata absent or very sparse ; receptacles 3-6 cm. (up to 12 cm.) long, 

 definitely delimited, much wider than the segments, single or bifurcate, 

 and mostly widely divergent, apices acuminate or acute ; conceptacles 

 numerous and prominent. 



Growing on rock ledges in the lower littoral belt. Kanaka Bay, 

 San Juan Island, Washington. 



Gardner, Genus Fucus, 1922, p. 29, pi. 22. 



This form of edentatus is closely related to forma hesperius. The 

 fronds average somewhat wider, more robust, the angles between the 

 segments are very much wider and more rounded, and the receptacles 

 mostly deeply bifurcate or single, widely diverging. The average 

 width of the segments is about 10 mm., but a few specimens were 

 found with extremely narrow segments, about 3 mm. These were 

 profusely branched, with wide angles, and small diverging receptacles. 

 Also a few specimens were found with the characters of the form, but 

 were 15 mm. wide. These few specimens are to be considered as the 

 extremes in individual variation in this particular character. 



