[439] THE ALG^E 203 



Family CERAMIACEsE. 

 Calithamnion floccosum pacificum Harv. 



On Nereocystis priapus and other algae, and on rocks. Puget 

 Sound; Lowe Inlet (15) ; Yakutat Bay (210, 244, 199). 



The most abundant species of Calithamnion on the Northwest 

 coast. 



Calithamnion plumula Lyngb. 



This species was collected several times in Puget Sound but was not 

 seen in Alaska waters. It is a comparatively common plant in Puget 

 Sound, while on the central California coast it is very rarely found. 



Ceratothamnion pekeanum (Harv.) J. Ag. 



On rocks in exposed localities in the littoral and upper sublittoral 

 zones. Sitka (152) ; Yakutat Bay (211); Shumagin Islands (373). 



The northern plant is smaller and with shorter branches than the 

 same species from the California coast. 



Ptilota asplenoides Ag. 



Abundant on rocks in the sublittoral zone. Yakutat Bay (198, 219) ; 

 Prince William Sound (269). 



Ptilota plumosa Ag. 



Attached to rocks and large algae in the sublittoral zone. Sitka 

 (140) ; Shumagin Islands (397). 



A much finer and more delicately branched plant than the last, with 

 opposite similar branches. 



Ptilota serrata Kuetz. 



In the sublittoral zone. Shumagin Islands (355). 



Antithamnion boreale (Gobi) Kjellm. 



Occasional in the sublittoral region. Wrangell (55) ; Sitka (135). 



In its general appearance the plant agrees with A. boreale corallina 

 but the branches near the apex are not elongated as in that form. 



Ceramium rubrum Ag. 



In the sublittoral zone. Sitka (127) ; Prince William Sound (275). 

 The Prince William Sound material, collected in June, bears an 

 abundance of mature carpospores. 



Ceramium codicola J. Ag. 



Attached to Codium mucronatum californicum, Sitka (170). 



The plants are small and sterile, but agree with specimens of C. 

 codicola collected by the writer on the California coast, and with speci- 

 mens distributed in the Phycotheca Boreali-Americana. 



