98 



Laminaria angusta. But the absence of lacuna mnciferse in the stem 

 of the latter tells us the difference at once. 



Sori are formed as a rule only on one surface, but they are some- 

 times found on both surfaces. 



The plant of this species grows in abundance along the eastern 

 coast of the Hokkaido, especially between Cape Nosafu and Cape 

 Erimo ; as we proceed southward, it gradually diminishes in number 

 and size. 



Laminaria Peterseniana Kjellm.^ 



Nom. jap. nov. Hira-e-kombu. 

 Nom. jap. Loc. Waniura-lwmbu or Hiro-me, Awo-wakame or 

 Bishamon-wahame. 



This species was at first discovered in the Groto group which is 

 situated to the westward and not far distant from Nagasaki. It also 

 grows in the island of Tsushima where it attains its maximum growth. 

 Eecently de Toni in his Syllog. Alg. III. p. 350 added two localities, 

 Tajima and Shimoda. Laminaria Peterseniana also grows abundantly 

 in Boshu, and Kubiri-mura, both not far distant from Yokosuka. From 

 Boshu I got abundant materials which were obtained on rocks or stones 

 at a depth of 10-15 fathoms. They have generally short compressed 

 winged stem and a shorter but equally broad lamina. The length of 

 their stem varies from 2 to 20 cm and that of lamina from 50 to 150 

 cm with a breadth 20-30 cm. The breadth of lamina does not much 

 differ from the specimens in the southwestern parts, but the length of 

 stem and lamina is much less (according to Kjellman's description 

 stipe measures 65 cm in length and lamina 3.5 m with a breadth of 

 25-30 cm). The following measurements show the proportions of parts 

 in the materials from Boshu. 



Total lenyth of 



Length 



Length of the 



Greatest 



Length of the 



Breadth of 



the alga. 



of the stipe. 



lamina. 



breadth. 



median linear sorus. the sorus. 



130 cm 



9 cm . 



.. 121 cm . 



.. 30 cm 





110 cm 



... 4 cm 



128 



.. 5 



.. 123 



.. 24 



... 



55 



... 7 



105 



.. 10 



.. 95 



.. 20 



... 



45 



... 5.5 



90 



... 9 



.. 81 



.. 20 



... 



60 



... 5.7 



80 



.. 3 



.. 77 



.. 14 



... 



26 



... 5 



55 



.. 20 



.. 35 



.. 10 



... 



— 



... — 



48 



.. 16 



.. 32 



.. 11 



... 



— 



... — 



30 



.. 13 



.. 17 



6 



... 



— 



... — 



1) KjeBlm. et Petersen ibid. p. 266. 



