100 



branous. A full-grown fructified sporophyll attains a length of 15-20 

 cm by 10-15 mm and has a thickness of 1.5-2 mm. In such a one, 

 the basal thicker portion gradually becomes thinner and narrows some- 

 what toward the base of the membranous portion. The membranous 

 portion more or less dilates toward the apex, assuming an oblong or 

 elongated sub-cuneiform shape, ending in an obtuse apex. Now a sorus 

 makes its appearance in the basal part of the membranous portion, 

 forming patches ovate, oblong, or semiovate (Fig. 15). It is 10-15 mm 

 long by 7-8 mm leaving narrow marginal portion and the rest greater 

 part naked. When Zoospores are emitted, the membranous portion falls 

 away, leaving behind only the thicker part, which then assumes a thick 

 scalpel-like appearance. The thick sporophyll carries a very narrow 

 wing along both margins, so that it is ancipitous in a cross-section. 

 Even this afterwards decays by and by, and finally falls off. 



This plant has a narrow range of its distribution, it being known 

 from the Hakodate to Rikuchu southward. 



Botanical Laboratory of the 4th Higher School, Kaga, Japan, 



November 10th, 1896. 



EXPLANATION OF FIGURES IN PLATE VII. 

 Laminaria longipedalis Sp. Nov. 



Fig. 1. — Fructified frond of the second year (1/10), with a cross-section of the 

 stem (nat. size). 



Fig. 2. — Fructified frond of the first year (1/10), with a cross-section of the stem 



(nat. size). 

 Fig. 3. — Cortical portion of the stem ; 50/1. 



Laminaria japonica. 



Fig. 4. — Cortical portion of the stem ; 37/1. 



Laminaria angusta. 



Fig. 5.— Portion of a cross-section of the lamina; 50/1. 



Laminaria gyrata Rjellm. 



Fig. 6. — Portion of frond bearing sori (cross-hatched patches) ;'' nat. size. 



Fig. 7. — Cortical portion of the stem of /. linearis; 240/1. 



Fig. 8. — A young plant of /. latior with one primary holdfast ; nat. size;. 



Fig. 9. — The same with two holdfasts ; nat. size. 



Fig. 10. — Holdfasts of the plant drawn in fig. 9; a the primary one. 



