Enumeratio Specierum Nemalionis et Hel- 

 minthocladiae Japonicae. 



By 



Seiichi Narita. 

 With Plate I. 



..". 



Nemalion Targioni-Tozzetti. 



Nemalion vermiculare Sir. Illustr. Alg. du Jap., 1. p. 91, t. 

 XXXIV; Hariot, Alg. de Yokoska, p. 218, No. 24-; De Tom, Phyc. 

 Jap. NOV., p. 19, No. 3 ; Id., Syll. Alg., IV, p. 78 ; Okam., Nippon S.-rui 

 Meii (Enumeratio AJgarnm Japonicarum), Ed. II. p. 312; Vendo, Text 

 Book of Marine Botany (in Japanese), p 525, fig. 150. = .V. liibricurn 

 Matscmura (non Dubv), Shokubutsu Meii, Ed. I, p. 194; Okam., I.e., 

 Ed. I. p. 13 ; Yendo, I.e., p. 527 (non alior). 



In the external appearance of frond the present species can 

 hardly be separated from A*, lubricum DuBY. The distinction 

 between them hitherto mentioned lies on the relative thickness 

 ol the .'ixU and the cortex. Careful observation on many 



Specimens Ol hoth species from various localities have led me In 



conclude that the diameter of the axial part as well as the 

 length ol the assimilators are never constanl as to put Bpecific 

 importance upon them. The axis has always largest diameter 

 in the lower pari of frond, gradually decreasing upwards. Vet 

 the two Bpecies may be distinguished one another by the shape 

 and size of the cells of the assimilators. In .Y. lubricum Duby, 

 the cells ol the terminal parti ol the assimilators are elliptical 

 and moniliform, and have larger diameter, measuring 9 ISfi ; in 

 A', vermiculare Sua. they ace cylindrical, slightly constricted al 

 the joints, and bave the diameter 6 1 I • This poinl ol disi 

 Hon, however, i- ool absolute, bul pi nation i>< some 



