342 University of California Publications. [botany 



floccosum var. Pacificum; Pleasant Beach, Kitsap County, Wash., 

 N.L.G., No. 346! 



This form, which is abundant on the western coast of North 

 America, grows in dense tufted masses. It is to be recognized 

 by its long, simple, subulate branchlets. 



Antithamnion Americanum (Harvey) Kjellman. 



On stems of Nereocystis and on wood, in the upper sublitoral 

 zone. Esquimalt, B. C, Harvey (1862, p. 175, under Galli- 

 thamnion Americanum) ; Friday Harbor, San Juan Island, Wash., 

 N.L.G., No. 502! 



The specimen from San Juan Island is referred here with 

 some doubt. The tetrasporangia are seeund on the branchlets, 

 but they are also provided with a unicellular pedicel. 



Antithamnion Pylaissei (Montagne) Kjellman. 



On Nereocystis and on wood, upper sublitoral zone. West 

 coast of Whidbey Island, Wash., N.L.G., Nos. 72!, 447!, 453! ; 

 Friday Harbor, San Juan Island, Wash., N.L.G., No. 503! 



The specimens referred here have a more verticillate habit 

 than the last, and are more slender than the next. They seem 

 to be distinguished better by habit than by any microscopical 

 character. 



Antithamnion Pylaisaei f. Norvegica Kjellman. 



Floating. Ludlow Bay, Jefferson County, Wash., N.L.G., 

 No. 438! 



Agrees well with Kjellmau's figure (1883, pi. 16, f. 1). 



Antithamnion subulatum (Harvey) J. Agardh. 



On larger alga?. Esquimalt, B. C, Harvey (1862, p. 175, 

 under Gallithamnion subulatum); Port Renfrew, B. C, Butler 

 and Policy, No. 40, and in Collins, Holden and Setchell, P. B.-A., 

 No. 944!; Vancouver Island, B. C, G. 11'. Lichtenthaler (in 

 Herb. F. S. Collins); west coast of Whidbey Island, Wash., 

 W.L.G., No. 922! 



A coarser species than the preceding and with the pinnules 

 provided with short subulate lateral branches. The type seems 

 to have disappeared, since Professor W. G. Farlow has searched 



