THE ALG^ 433 



Porphyra laciniata (Lightf.) Ag.^ 



On the stems of Fiiciis and on rocks in the littoral and sublittoral 

 zone, Yakutat Bay. 



All specimens obtained were sterile. 



Porphyra perforata J. Ag. 



On rocks in the littoral and sublittoral zones, Glacier Bay (lOo); 

 Sitka (130) ; Shumagin Islands (394)- 

 The most abundant species. 



Porphyra amplissima (Kjellm.) Setchell & Hus. 



On rocks in the sublittoral zone, Prince William Sound. This large 

 and beautiful species was found growing in great abundance at this 

 station but was not collected again. 

 Porphyra miniata forma cuneiformis Setchell & Hus. 



Usually found floating, occasionally attached to stems of Nereo- 

 cystis and other algae ; Lowe Inlet (20). 



Porphyra tenuissima (Stroemf .) Setchell & Hus. 



Abundant on rocks and also epiphytic on algte. Sitka (148a, 137) ; 

 Yakutat Bay (214). 



Not previously reported from the west coast of North America. 



Family HELMINTHOCLADIACE^^. 

 Batrachospermum vagum flagelliforme Siridot. 



In ponds, pools and streams near Virgin Bay, Prince William 

 Sound (299) ; Cook Inlet (423) ; Kadiak Island. 



Plants collected in June and July at or near sea level bore an abund- 

 ance of mature carpospores. 



Family GELlDIACEyE. 



Choreocolax polysiphoniae Reinsch. 



On the stems of Polysiphonia sp., Sitka (123a). 



Plants collected in June bore only tetraspores. The 'plants are 

 closely attached to the lower part of the main stem of the Polysi- 

 phonia^ spherical, dark brown or black, about J^ mm. in diameter. 

 The tubes of the Polysiphonia are much deformed wherever the 

 "parasite" is attached. The central tube is much enlarged, the sur- 

 rounding ones somewhat so, the walls considerably contorted and 

 thickened. This species has been found in the Atlantic on the Euro- 

 pean and American shores but has not been previously reported from 

 the Pacific ocean. 



1 All specimens of the genus Porphyra were identified by Dr. Setchell and 

 Mr. Hus. 



