vor.. 11 Setchell-Gardner . — AlgcB of N'ortJitvestern America. 169 



Sitka, or even to Yakutat Bay or farther west on the shores of 

 the Gulf of Ahiska. When we enter Bering Sea, however, even 

 many species, characteristic of the Boreal Region in its lower 

 part, stop but some continue on even into the northern part. 

 There are some reasons, at present not supported by as strong 

 evidence as may be desired, for believing that it may be neces- 

 sary ultimately to distinguish between an Upper and a Lower 

 Boreal Region. The distribution of Thalassiophyllum, and of a 

 few. other species point toward this. The Boreal Region is to be 

 characterized by the occurrence of Laminaria saccharina in 

 various forms, certain Alarife, certain digitate Laminariae, 

 Chorda, BJiodymenia pertusa (P. & R.) J. Agardh, forms of 

 R. palmata, Agarum etc., to say nothing of the large and con- 

 spicuous Alaria fistnlosa P. & R. which, however, is one of the 

 species which does not extend down into the vicinity of Puget 

 Sound. The Boreal Region has a distinct admixture of Arctic 

 and North Atlantic species, or of species allied to these and dis- 

 tinct in type from those of the North Temperate Region. As we 

 proceed north into the Bering Sea, this Arctic cast becomes more 

 distinct as the number of species becomes less and many of the 

 characteristic species of the Lower Boreal are conspicuous by 

 their absence. Of the Arctic coast of Northwestern America, we 

 know nothing, or practically nothing, of the algal inhabitants. 



In this account, we have included such of the Aleutian Is- 

 lands and the islands in Bering Sea as belong to the United 

 States, more for reasons of convenience than any that are purely 

 geographical or floral. An account of the species of Bering 

 Island and of the Ochotsk Sea would come naturally into a con- 

 sideration dealing with the shores of the Bering Sea, but for 

 reasons of lack of opportunity of examining specimens from these 

 shores, must necessarily be omitted. 



We have spoken of regions of distribution, as may be i)lain 

 from the text, from the point of view of the marine alga3. We 

 have included in our account the species of the fresh waters and 

 damp places of the coast country also, since the materials have 

 come to us with the other, but as regards distribution, they do 

 not fall into line with the marine species. 



The physical geography of the Northwest Coast is, in general,- 



