228 University of California Publications. [botany 



Cladophora Alaskana F. 8. Collins sp. now 



Tufts 15-25 cm. high, erect, main filaments about 300 h- 

 diam., articulations one-half to one and one-half diam., branches 

 similar, erect, scattered or in secund series of two or more, not 

 tapering, terminal cells blunt, wall thick, striate: branches near 

 base of the tuft slenderer, 200-250 m diam., with thinner walls, 

 not striate, with numerous short, patent or recurved ramuli, 

 scattered or in secund series. Color dark green, becoming whit- 

 ish on exposure. 



On rocks, forming a distinct belt at the lower tide limit. 

 St. Paid Island, Alaska, Herb. 1). G. Eaton, No. 4! ; west shore 

 of Amaknak Island, Bay of Unalaska, Alaska, W.A.8. and 

 A.A.L., Nos. 3259!, 4000!, 5045a!, and in Collins, Holden and 

 Setchell, P. B.A., No. 917! 



The slender divaricate lower branches resemble somewhat the 

 interlacing branches in the subgenus Spongomorpha, but they 

 are not clearly differentiated, the two forms of branches in this 

 species passing into each other. The tufts are never densely 

 matted as in Spongomorpha. 



Cladophora Hutchinsiae var. distans Kuetzing. 



Port Renfrew, B. C, Butler and Volley, No. 127! 



Mr. Collins says of this, that it may be the plant called 

 O. laterirens by Harvey in his "List" (1862), but that it is not 

 the plant properly to be placed under that name. 



The species of Cladophora arc always difficult to determine, 

 and this is especially true of the species of the Pacific Coast of 

 North America. All of our material has been sent to Mr. Collins 

 and besides his special reports on each specimen, he has written 

 the following account of the result of his study of the Ruprecht 

 descriptions, supplemented by a considerable number of Ruprecht 

 specimens in Herb. Parlow. His report reads as follows: 



"Ruprecht gives nine species, all of the Acrosiphonia-group 

 as follows: 



1. C. cohrerens. 4. ('. viminea. 7. ('. cartilaginea. 



2. C. Chamissonis. 5. C. saxatilis. S. C. seopspformis. 

 :>. C. Mertensii. li. C. duriuscula. 9. C. coalita. 



