Jan.. 1916.] 



K. OKAMURA.— MARINE ALGAE. 



Turhinaria omata J. Ag. Sp. Alg. I, p. 206, Bart. Syst." Struct. 

 ' Account of Turbin. p. 219 ; Fuciis titrbinatus var. ornatus Turn. 

 Fuc. Vol. I, p. 50, t. 24, f. c-li. 

 Ponape (Yanagi), Truk (Miyake, Fujita), Palau (Okada). 

 Distr. : Indian Ocean, Malay Archi-^elago, Pacific Ocean, Ryukyu, 

 Sargassum cristaefolium Ac; J. Ag. Sp. I. p. 325. 

 Ponape and Saipan (Yanagi), Palau (Okada). 

 Distr. : Ceylon, Manila, Sunda Isl., Japan. 



Dilophus radicans n. sp. PI. I, fig. 1-6. 



Diagn. : Fronds narrow, linear, ancipito-compressed, form- 

 ing loosely entangled 

 mass, rooting and 

 creeping on other 

 algae, irregularly and 

 distichously branched 

 in opposite and alter- 

 nate manner, patent ; 

 inner cells four layers, 

 not areolated in sur- 

 face view. 



Entangled among 

 the fronds of Laurencia ; 

 Ponape (Yanagi). 



Fronds narrow 

 linear, slightl}' anci- 

 pito-compressed (0.2— 

 0.5 mm., scarcely one 



Fig. 2 

 Fig. 1. Surface view of frond of Dilophus radicans n 



152 



sp., -j- 



Fig. 2. Longitudinal section of frond, -^ 



mm. broad), forming loosely entangled depressed mass, creep- 

 ing on the frond of another alga, emitting tufted or scattered 

 root fibres from places where the frond comes in contact with 

 the substratum. Branches arising irregularly in opposite and 

 alternate manner, distichous, patent, standing on roundish 

 axils. Lower portion of frond slenderer, becoming a little 

 wider above, and acuminate at apex. Young branches are 

 almost tooth-like. Cross-section of main branches elliptical 

 showing four layers of cells in the median portion of the 

 section, with a few cells at both margins. Cortical cells rect- 



