688 University of California PuhlicaUons in Botany [^^ol. 8 



receptacles definitely delimited, complanate to moderately tumid, 

 deeompositely furcate, mostly spreading and acuminate, 3-4.5 cm. 

 long ; conceptacles numerous, conspicuous. 



Growing on boulders, logs, etc., in the lower littoral belt. Sack- 

 man's Point, near Tracyton, Kitsap County, Washington. 



Gardner, Genus Fucus, 1922, p. 49, pi. 53. Fuciis evanescens, 

 Tilden, Amer. Alg. (Exsicc), no. 235. 



Tilden's no. 235 seems to belong here, although the specimen in 

 Setchell's copy of her American Algae is only a fragment and just 

 beginning to produce receptacles. 



The distinguishing character of this form is the deeompositely 

 furcate receptacles, often widely divergent. As many as eight diver- 

 gent apices have been observed with a common base. The fronds are 

 decidedly flaccid and dissolve rather readily in fresh water after 

 being dried. 



7. Fucus evanescens f. intermedius Gardner 



Fronds foliaceous, flaccid, 12-18 cm. high, light brown to yellowish, 

 dark brown on drying, holdfast and stipe small, angles broad, rounded ; 

 segments linear, reduced above each forking, 1-2 cm. wide, crypto- 

 stomata 15-25 per sq. cm., midrib narrow, prominent, percurrent, alae 

 relatively wide, membranaceous ; receptacles broad at the base, 1-2- 

 furcate, acuminate or acute, complanate or tumid with mucilage, 

 definitely delimited ; conceptacles small, numerous. 



Growing on rocks in the middle of the littoral belt. East Sound, 

 Orcas Island, Washington. 



Gardner, Genus Fucus, 1922, p. 44, pi. 44. 



This form seems unmistakably connected, through its narrow 

 specimens, with F. evanescens f. costatus on one side, and, on the other 

 side, through its widest specimens, it seems not unlike certain narrow 

 specimens of F. evanescens f. pergrandis. It differs from the former 

 in having wider segments not perceptibly reduced in width, as in 

 f. costatus, above the forkings, and in having wider, much more robust 

 and blunt receptacles. From the latter it differs in being much less 

 robust throughout, in having fewer cryptostomata, and in having much 

 more delicate and membranaceous alae. 



