A Monograph of the Geniis Alaria. \QJ 



the eastern and the southern coast, considering the type locahty 

 as the center of its distribution. 



Remarks on the relatiomhip to other species. The present species 

 has a close resemblance in many respects to A. esculenta of the 

 Atlantic coasts. If both had been found near each other, one 

 might well have been taken as a variety of the other. The only 

 and marked distinction between them lies in the considerable 

 thickening of the matured sporophylls of the present species. The 

 species, however, has only a limited area of distribution and can 

 not in any way represent in the Pacific the position of A. esculenta 

 in tlie Atlantic. 



The specimens collected on the coast of Hidaka Province 

 generally have the sporophylls much thinner and broader than the 

 typical form and the matured ones apparently holosoric. The 

 characteristic arrangement of the sporophylls is obliterated in 

 them. They are to be determined as A. prcelonga K.jellm. 

 better than as the present, if the blades had not been frosted 

 with rich cryptostomata. It is not seldom to find a specimen 

 which appears to link the two species. This view is much 

 strengthened by the relative positions of their distributive areas. 

 A. prœlonga is found in the southern part of Kamtschatka, and 

 then along the Kurile group as far south as near Cape Erimo, 

 Hidaka Province, on the coast of Hokkaido. It there disappears 

 and in its stead the present plant occupies the coasts further south- 

 westward. As the intermediate forms are usually confined to about 

 the crucial region of the two species, one might be regarded as a 

 variety of the other due to the locality. The typical forms of both, 

 however, are so well marked that I can not bring them together 

 in our present conception of species. 



A parallel example may be given in Laminnria. The vicinity 



