July, 1917.] x. YENDO:— NOTES ON ALGAE NEW TO JAPAN. VII. 195 



well shown in the figures. The only difficulty in amalgamat- 

 ing it under this species is the simple, disc-form root. 



The species has a strong resemblance with C. malagonium. 

 But the thick, rigid and shining membrane — very likely irides- 

 cent in the water when alive — , of the basal cell of frond soon 

 distinguishes the species from the allies. 



Locality. Bonin Islands (T. Arima, No. 19). 



Distribution. Canary Islands ; Barbados ; West Indies ; 

 Panama ; Morocco ; Indian Ocean ; South Pacific Ocean ; 

 Hawaii. 



Boodlea siamensis Rbld. 



Flora Kohchang, p. 107. — Id. : Siboga Exped., Chlorophyc, 

 p. 68, fig. 11. — Okamura : Mar. Alg. Carol, and Mariana, p. 6. 



Of hitherto described five species of Boodlea, we have 

 already found two, B. coacta and B. composita, on our coast. 

 Among the collections of algae lately sent from Mr. Arima in 

 the Bonin Islands, I have found two well-prepared specimens 

 which satisfactorily agree with the named species. This locality 

 may be taken at present as the northern extremity of its 

 distribution. 



Locality. Bonin Islands (T. Arima, No. 10). 



Distribution. Gulf of Siam; Red Sea; Dar es Salam ; 

 Samoa; Tongatabu; Palau. 



Sargassum Grevillei J. Ac 



Spec. Al^'. I, p. 336. — Id. : Spec. Sarg. Austr., p. 105. — Du 

 Tom: Syll. Alg, Ill, p. 81. — Rkinui.d. : in YVkhkk van I'.ossk ; Listc 

 des Al^. Siboga, I, p. 155. 

 - Sargassum porosum Gkbv. : Alg. Orient, in Ann. and Mag. Nat. 



II, si. ill, ,,. L06, PI. IV, and in Trans. Bot. Soc. Bdinb. III. p. 



93, PI. IX. 

 = Sargassum microcystum Ykndu (non J. Ac): Fucaceae Japan, 



p. 138. 



