﻿PLATE IV. 



Herposiphonia fissidentoides (Holm.) Okam. 



RHODOMELACE/E. 

 NOM. JAP. Hime-goke. 



Herposiphonia fissidentoides (Holm.) Okam. Contrib. to the Knowl. 

 of the Mar. Alg. of Japan, III, p. i o - 1 1 , PI. I, fig. 9-1 r. — Polyzonia 

 fissidentoides Holmes, New Mar. Alg. Jap. No. 22. t. XII, f. 2 a - b. 

 (Journ. Linn. Soc" Bot., Vol. XXXI.) 



Fronds creeping on various kinds of calcareous algae, de- 

 cumbent, rooting from under surface. The " Lang trie be " arise 

 alternately from every fourth articulation ； and the " Kurztriebe," 

 which are flat and leaf-like, stand almost horizontally in double 

 rows along the upper side of the decumbent stem, p-iving a 

 dorso-ventral appearence for the plant. The latter arranp-ement 

 of the " Kurztriebe," however, is rather obscure ; for, although 

 the leaves (i.e. " Kurztriebe j are in reality inserted on the 

 dorsal side of the shoot, }'et they spread out very widely on both 

 sides, and appear to lie apparently on the same plane as the 

 " Lanp" け iebe." The " Krmtriebe" (i.e. leaves) varies from ovato- 

 lanceolate to oblong*, ending in a broadly acute apex with a 

 tapering or constricted and oval base. The broader leaves slightly 

 overlap one another with their edp-es. The length and the breadth 

 of leaves measure 560-750 ！ f- and 131— 281 / ノ- respectively. Their 

 surface is composed of horizontally arranged hexagonal cells of 

 approximately equal length (34-38 〃-) and shows 7—1 1 cells in 

 the widest row. The apices of " Langtriebe are not inrollecl, 

 but flat and straight ； the " Kurztriebe are patent or almost 

 horizontal, at first curvinpr towards the growing apex of the shoot, 



