[43 1 ] THE ALG^E 195 



Agarum turner! (Post & Rupr.). 



Abundant in the sublittoral zone. Yakutat Bay (2000) ; Prince 

 William Sound (261) ; Popof Island. 



This species differs from the last chiefly in its smaller size, more 

 ovate outline, and the much narrower midrib. Its relationship would 

 probably be better expressed by placing it as a variety rather than a 

 distinct species. 



Costaria turner! Grev. 



Abundant in the sublittoral zone from Puget Sound to the Shumagin 

 Islands. Victoria ; Sitka (187) ; Yakutat Bay ; Prince William Sound ; 

 Kukak Bay ; Shumagin Islands. 



The plant reaches a much larger size on the Alaska coast than on 

 the California and Washington coast. Specimens were seen measuring 

 from 1 80 to 220 cm. in length and 50 cm. wide at the base. 



Eisenia arborea Aresch. 



A broken fragment of this plant was obtained at Wrangell and 

 several specimens were obtained in Puget Sound. 



Macrocystis pyrifera (Turn.) Ag. (Plate LX.) 



In the elittoral zone off rocky points and in unprotected places. 

 Wrangell; Sitka (171, 189) ; Juneau. 



Although a constant watch was kept for this plant it was not seen 

 north of Sitka. 



Nereocystis priapus (Gmelin) Saunders. (Plates LVIII, LIX.) 



Ulva priapus GMELIN, Hist. Fucorum, 231, 1768. 

 Nereocystis lutkeanus MERT.. FIL. in Linnaea, p. 48, 1829. 



Abundant from Puget Sound to the Shumagin Islands. The plant is 

 seldom found growing in protected places, being confined to the elit- 

 toral zone at the mouth of bays and in the open ocean from a few yards 

 to a mile or more from shore. The plant, unlike Macrocystis pyrifera 

 and Alariajistulosa, does not form floating masses. 



Mature plants measure from 50-70 feet long, about two-thirds of 

 which is the long tube-like stipe with its terminal air bulb, which 

 floats the dichotomously torn lamina on the surface of the ocean. 



Mertens' statement, copied by Harvey, in which in speaking of the 

 stipes, he says : " They are said to be 45 fathoms long/' is probably 

 not true. The writer has measured many fully-developed plants on 

 the California, Oregon, and Washington coasts as well as on the 

 Alaska coast and has never yet found one exceeding the above figures. 



Gmelin's figures and description of Ulva priapus leave no doubt 

 as to the identity of his plant although he had only an imperfect stipe. 



