h ― 19U ― 



meration of of Japanese Algae ") p. 121， putting it under subfamily 

 Tabacopsideae of Fam. Demarestiaceae. More afterward, however, charac- 

 ters of its changing colour of frond, its having astringent and sour taste, 

 and its having midrib and veins led me to consider it as a species of 

 Desmarestia in relation with other plants of that genus, though the mode 

 of growth of frond is not known at present. The nature of reproductive 

 organ is now imperfectly known among the plants belonging to the 

 Family Desniarestiaceae, only unilocular sporangia having been detected 

 in some species of Desmarestia and Arthrocladia, If my identification 

 proves to be correct, then, the nature of plurilocular sporangia or 

 gametangia may be said to have been brought to light. 



PL. XXXVIII. Fig. 1 : frond of Desmarestia tabacoides Okam. n. 

 sp. bearing sori, s, s， ま. 一 Fig. 2: one of sterile hairs, ― Fig. 3: por- 

 tion of cross-section of frond with 2 gametangia and hairs. h、 h, 一 

 txg. 4 : different stages of the development of ^ametangia ； a, - 

 "/， -6; 凡 



PL. XXXIX， Fig. 9-13. Fi ん 9: portion of the cross-section of 

 thicker midrib ； c, the central axis ； -^. ― Fig. 10: longitudinal section 

 of the central axis, -"； え 一 tig. 11: cross-section of the same, ― Fig. 

 12: portion of cross-section of the lamina with a veinlet, -^. ― Fig. 13: 

 filaments forming the medullay layer of the membranous portion of 

 lamina, - 



Desmarestia Lamouroux 1813. 

 ' うるしぐ さ屬. 



DESMARESTIACEAE. うるしぐ さ 科. 

 體ハ 絲狀， 扁 壓又ハ 扁平 ュ シラ 「パ ンド」 狀 乃至 葉 狀ヲナ 



