[415] THE ALG^ 179 



sides of the Atlantic, but appears not to have been previously reported 

 from the Pacific. 



The follow^ing specimens of Cladofhora can be noted by numbers 

 only, specific determination being impracticable at present. 



Annette Island (17, 45, 48) ; Wrangell (56) ; on rocks. Glacier 

 Bay (86) ; forming masses on rocks, Sitka (157) ; on protected side 

 of exposed rocks. Virgin Bay, Prince William Sound (295). 



Family GOMONTIACB^^, 



Gomontia polyrhiza (Lagerh.) Born. & Flah. 



Popof Island. 



Basal layer growing in the substance of marine shells, erect filaments 

 extending to the surface, zoospores formed in sporangia. 



Family DERBESIA CE^^. 



Derbesia vaucheriaeformis (Harv.) J. Ag. 



On a sponge in Yakutat Bay (234). 



Filaments 30-40 (i in diameter, simple below^, dichotomous above, 

 branches patent, 20-30 ix w^ide, often with a cuboidal cell near the 

 base ; zoosporangia ovoid or pyriform, 140-200 by 50-80 /Jt, short-pedi- 

 celled. 



As there are no mature spores on this specimen, there is a possible 

 doubt as to the identification, but the characters agree well with the 

 species named. 



Derbesia marina (Lyng.) Kjellm. 



Sitka, in quiet water (149). 



Filaments 50-60 tx in diameter at the thickest, tapering slightly ; 

 sparingly branched laterally, usually two partitions found at the base 

 of each branch, enclosing a short cell; zoosporangia 150-180 by 90- 

 120 )u, short pediclled. 



Family VAUCHERIACE.^. 



Vaucheria sessilis (Vauch.) DC. 



On an overhanging dripping cliff, Juneau (74). 



Filaments up to 70 p. in diameter ; oogonia usually two or three to- 

 gether, sessile, ovate or ovate-oblong, about 60-150 /i, beaked ; anther- 

 idia in the vicinity of the oogonia, formed at the end of a short, hooked 

 or curved ramulus. 



With antheridia and oogonia. 



