52 University of California Publications in Botany [Vol. 10 



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 Rigg are 

 smaller and more nearly coincide with the description. This plate 

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

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

 tacles. There is a plant in the Herbarium of the University of Cali- 

 fornia, sheet no. 132618, contributed by Kjellman and collected on 

 Spitsbergen in "1872-73," labeled in Kjellman's handwriting, "Fucus 

 evanescens Ag.," which is almost a duplicate of the type specimen 

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

 lected 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 (cf. plate 56). 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 Professor Setchell, who states 

 that the plant is slightly smaller than the plant referred to in Setchell 

 and Gardner's Algae of Northwestern America, under f. typica, from 

 Harvester Island, Alaska. This plant is in the Herbarium of the 

 University of California under no. 99139. It differs only slightly from 

 the wide form of F. evanescens from Spitzberg'en, mentioned above, 

 having more numerous, larger, and better developed receptacles. 

 There is much greater disparity of size between this specimen and 

 Kjellman's f. "typica" than there is between Kjellman's f. "typica" 

 and his f. "limilata." If we admit the specimen determined by J. G. 

 Agardh from Spitzbergen as belonging with f. typica Kjellman, then 

 the Harvester Island specimen which is so close to it had probably 

 better be allied with it at present, until more is known of the forms 

 from that island. However, it also seems very close to Kjellman's 

 f. "cornuta," but has wider fronds and receptacles than the type 

 specimen of that form. 



I am referring here a series of plants collected on Kadiak Island, 

 Alaska, by G. B. Rigg, no. 100. These plants are only slightly wider 

 than the type specimen of Kjellman, and have numerous well developed 

 receptacles. They appear to be the closest in all characters to the 

 type, and I am taking them to be the best representatives of f. typicus 

 thus far discovered in Pacific Coast waters. 



