horizontally articulated. Tetrasporangia scattered, irregularly cru- 

 ciate. Carpogonisl branches and auxiliary-cell-branches are produced 

 in number, being formed as lateral branches of infra-cortical cells. 

 Cystocarps prominent, minute, globular with closed pericarp ; gonimc- 

 blast spherical faintly lobed, almost all articulations of spore-filaments 

 being transformed to spores. 



From the characters of curved auxiliary-cell-branches and 

 ooblastema filaments the genus is placed in the family Dniiiontiaccac. 

 Among hitherto-known genera of that family the present genus seems 

 to be placed in the vicinity of Cryptosiphonia from the point of 

 resemblance of the external habit of sterile frond. But, the characters 

 of central axis and cystocarps are quite different from those of that 

 genus, and I do not find close relationship with any genera of that 

 family. 



Hyalosiphonia coespitosa n. sp. 



Nonii Japi ; Iso-mume-inodoki. 



PL. LXIV, PL. LXV, Fig. 1-6. 



Fronds elongated, coespitose, rising from a scutate disc, filiform, 

 cylindrical, tapering to both ends, either furnished with a percurrent 

 stem or dividing into some main divisions, irregularly branching on all 

 sides, 10-30 cm high. Branches often elongated, patent and weak, 

 somewhat thickly furnished with longer or shorter ramuli, some of 

 which elongate into normal branches which are in turn loaded with 

 ramuli. Even the percuiTent stem or main branches are more or less 

 thickly iurnished with short ramuli. All the branches filiform and 

 patent, tapering to a fine apex. Ramuli short and slender, tapering 

 to both ends, 5-10 mm long. -Tetrasporangia scattered over bran 



