92 



the stem. But some hesitation still lingered in my mind in separating 

 those plants from L. gyrata. I begun to doubt whether in L. gyrata 

 lacunae were not present in the stem of some examples and whether my 

 plants in question were not a form or variety of that species. Thereupon 

 I studied several examples of L. gyrata and I was fortunate enough 

 to discover the fact above referred to. 



Based upon the fact that lacunae are present in the stem of L. 

 gyrata and are somewhat variable in their existence, I distinguish 

 three forms of this species, viz. /. linearis, f. latior, and /. obovata. 



Laminaria gyrata Kjellm. — " Rhizinis attenuates, stipite brevi, i:iferne tereti, crassiuscule, 

 superne crompresso, attenuate), in laniinam sensim abeunte, levi, lacunis muciferis nullis 

 corticeque deciduo deficiente ; lamina lineari-lanceolata, angusta, demum pergamea, fascia 

 angusta, fere coslae-formi pereursa, inarginibus planis vel subundulatis ; soris in utraque superficie 

 laminae inferne evolutis, marginalibus fasciam medianum medarn relinquentibus, numcrosis, 

 parvulis, elevatis, distincte circumscripti, vel subcircularibus vel secus directionem laminae 

 transversalem elongatis, plus minus ramosis, structura vulgari. — ad Hokkaido- Stipes 4-5 cm 

 longus, lamina 7-8 cm latkudine metiens ; consistentie ut in Laminaria saccharina*"' — Gr. B. de 

 Tom Syllog. Alg. III. p. 348. 



/. linearis. Characters same as above. 



Hab. Akkeshi in the Hokkaido. 



It is to be added to the characters stated above, that lacunae are 

 more or less present in the stem. Of the existence of lacunae in root 

 fibres I can say nothing, for in my specimens roots are unfortunately 

 wanting ; but from their presence in other two forms it may be said that 

 they are more probably present in root fibres. 



/*. latior. Stipe short, 4-7 cm long, ca. 5 mm in diameter, provided with a ring of 

 muciferous lacunae; lamina linear lanceolate, 50-100 cm long, 10-17 cm broad, oval or 

 cuneate at base, slightly dilated above, with margins flat at base, more or less undulated above. 

 -Fig. 6- 



Hab. Urupp, Etrofu, Shikotan, Akkeshi. 



Stipe is subcylindrical below, slightly compressed above, attenuated 

 with a close ring of muciferous lacunae, which assume an elongated 

 angular chink-like appearance. Lamina is linear, with generally ovate 

 base which is more roundish in some, more cune ite in others. Lamina 

 has a tendency to dilate slightly above the middle point of the length 

 of the specimen. Margin is flat in basal portion, j^ undulated above, 

 and especially so in broader or thinner lamina. The median fascia is 



