1923] Setchell-Gardner: Melcmophyceae 6s:; 



17. Cryptostomata 12-25 per square centimeter 7. f. intermedius (p. 688) 



18. Fronds fruiting in different zones 15. f. limitatus (p. 694) 



18. Fronds fruiting in the same terminal zone 19 



19. Fronds irregularly branched and distorted 14. f. irregularis (p. 693) 



19. Fronds regularly dichotomous 1. f. typicus (p. 683) 



1. Fucus evanescens f. typicus Kjellm. 



Fronds 15-25 cm. high, coriaceous, dichotomous, dark brown ; seg- 

 ments cuneate to sublinear, midrib moderately distinct, percurrent, 

 cryptostomata few, small; receptacles mostly complanate, deeply 

 furcate, segments obovate to linear-acuminate. 



Growing on rocks in the upper littoral region. Harvester and 

 Kadiak Islands, Alaska. 



Kjellman, Om Spets. Thall., II, 1877a;, p. 3 ; Setchell and Gardner, 

 Alg. N.W. Amer., 1903, p. 282 ; Gardner, Genus Fucus, 1922, p. 51, 

 pi. 56. 



Setchell and Lawson, no. 5122 (Herb. Univ. Calif., no. 99136), 

 Harvester Island, Uyak Bay, Alaska ; Bigg, no. 100, Kadiak Island, 

 Alaska. 



We have a photograph of Kjellman 's type specimen of this form. 

 It represents a plant considerably smaller than the plants which we 

 have allied with it from the Alaskan waters. No. 5122, in particular, 

 is much more robust than Kjellman 's description calls for. The 

 receptacles are much longer and wider, but this may possibly be 

 accounted for by difference in age. The plants collected by Bigg are 

 smaller and more nearly coincide with the description. This photo- 

 graph shows Kjellman 's plant to be about 10 cm. high, possessing 

 distinct midribs in many of the segments, and to have relatively small 

 receptacles. There is a plant in the Herbarium of the University of 

 California, sheet no. 132618, contributed by Kjellman and collected 

 on Spitzbergen in "1872-73," labeled in Kjellman 's handwriting, 

 "Fucus evanescens Ag.," which is almost a duplicate of the type speci- 

 men mentioned above. There is also a plant in the same herbarium, 

 collected in 1868 from the same locality and determined by J. G. 

 Agardh as F. evanescens Ag., whose fronds are about twice as wide 

 as those of the Kjellman plants. Otherwise all of these three collections 

 of plants are very much alike. 



The type specimen of F. evanescens Ag. is in the herbarium of 

 J. G. Agardh at Lund under no. 00299. It has been examined by one 

 of us (Setchell) who finds that the plant is slightly smaller than the 



