1920] Sctchcll-Gardncr: Chlorophyccae 225 



those of S. arcta (uj) to 200/a or over at the tips), but we have seen 

 none approximating the maximnin diameter (500^1 at the tips) given 

 for the Atlantic-Arctic plants. The Tihlen specimens (American 

 Algae, no. 374), issued as Cladx>phora arcta form h, and a.ssigned to 

 C. Ilijstrix by Setchell and Gardner (1903, p. 226), prove on exam- 

 ination to have compound hooked branchlets and have been assigned, 

 consequently, to Spongomorpha- coalita in this account. Specimens 

 from Karluk and from Uj'ak Bay, Alaska, assigned by Setchell and 

 Gardnei- to Cladophora arcta and its form conglutinata are now 

 referred here, after careful examination. The status of this species 

 on our coast, however, is subject to careful revision as soon as more 

 abundantniaterial for study and comparison is available. 



Spongomorpha Hystrix might be compared with 8. duriuscula, 

 so far as description goes, but the species are very different in aspect, 

 tlie former being closel}' matted together below, while the latter shows 

 so loose an intermingling of the filaments as to suggest tlie possibility 

 of its belonging rather to Cladophora than to Spongomorpha. The 

 segments also in *S^. duriuscula are usually shorter and those of the 

 main filaments are horizontallv striate. 



3. Spongomorpha duriuscula (Rupr.) Collins 



Tufts 15-25 cm. high, erect, loose, main filaments firm, straight, 

 with thick, horizontally striate walls, 200-250/a diam. below, 300/.1 at 

 the tip; segments 0.5-1.5 diam. long, 2-3 diam. at the blunt tips; 

 branches similar, erect, scattered or in secund series of two or more ; 

 near the base of the tuft more slender, 150-200/i. diam., with thiinier 

 walls, not striate, with numerous short, patent ramuli, scattered or 

 secund. 



Growing on rocks in the upper sublittoral and lower littoral belts. 

 Alaska (Pribilof Islands to Karluk). 



Collins, Green Alg. N. A., 1909, p. 357. Cladophora ala.skana 

 Collins, in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 

 no. 917 (nomen nudum), in Setchell and Gardner, Alg. N.W. Amer., 

 1903, p. 228 (description). Conferva duriuscula Ruprecht, Tange, 

 1851, pp. 401-404. Conferva cartilaginca Ruprecht, Tange, 1851, 

 p. 404 (fide Yendo). Acrosiphonia duriuscula Yendo, Notes on algae 

 new to Japan, V, 1916, p. 246. 



The type locality of Conferva duriuscula Ruprecht is Unalaska, 

 where it was collected by Wosnessenski (no. 108) as the type specimen 



