234 University of California Publications. [botany 



genus Alaria and contributed determinaions and notes without 

 which our account would have been extremely meager. 



In this group we find a mixture of forms of North Atlantic 

 affinities mixed with types of Antarctic affinities. The genera 

 Macrocystis, Nereocystis, Lessonia, Postelsia, Dictyoneuron, and 

 Egregia are most closely related to Laminariacea? of the Ant- 

 arctic Ocean, some species of Chorda, Lam in aria, Agarum, 

 Alaria, and Fucus are identical with those of the North Atlantic, 

 while others of the same genera are very closely related to the 

 North Atlantic forms. We have selected the species and genera 

 just mentioned, because they are large and typical. A detailed 

 list would only show the same thing and make the proportions 

 plain. The proportions, however, if taken from such a list as 

 could be compiled at present, would probably not hold as soon as 

 we have a little more complete knowledge than we have at pres- 

 ent. Iu the group of the Pha^ophyceae, too, we see the mingling 

 of the algal flora of the North Temperate Region and the Lower 

 Boreal Region very plainly. The Antarctic types belong properly 

 with the North Temperate, although some of them, notably 

 Nereocystis, extend through the Lower Boreal, but are wanting, 

 as we have reason for believing, in the Upper Boreal. The 

 North Atlantic types, on the other hand, are characteristic of the 

 Lower Boreal and are represented in the North Temperate by 

 fewer species or mostly by species related to, but not identical 

 with, the species of the North Atlantic. A comparison with the 

 Phseophyceae of the northeastern coast of Asia, is not possible, 

 at least with the expectation of satisfactory results. The algal 

 flora of Ochotsk Sea, is very similar to that of Bering Sea, and 

 this Upper Boreal flora reaches to the northern extremity of 

 -I a pan, but beyond that our present knowledge of the flora of 

 -Japan in the Lower Boreal Region is not sufficient to allow any 

 very definite statements to be made. A comparison with the 

 coasts of the United States below Cape Flattery might be made, 

 especially with those included in the North Temperate Region, 

 but it is sufficient to say that many of the species of that flora 

 have already been found in the lower limits of the Lower Boreal 

 Region and many more will probably be added when our knowl- 

 edge approximates completeness. 



