26 



Remarks. Specimens of the present plant before me are younger 

 forms and are few in number. From .the want of knowledge of its 

 fully grown frond and from the absence of fruits its true affinity at 

 present is not distinctly known ; but taking the mode of growth into 

 consideration we may perhaps refer it to the section Odontophora in 

 which Delesseria Lyalii Hook el Harv. and D. similans J. Ag. are 

 comprised (J. Ag. Epicr. p. 487). With those two plants it presents no 

 affinity. Among hitherto known species of this genus, a's far as I 

 know from J. Agardh's Epicrisis, we find no one which has a habit 

 more or less similar to the present species. In Zanardini's Phycearum 

 Indicarum p. 141 a decumbent-rooting species of Delesseria with the 

 name D. adnata Zanrd. is mentioned which differs from the present in 

 many important points. 



Rytiphloea angusta sp. nov. 



Syn.? RytipMcea complanata var. pusilla Harv. 

 Cha. new alg. no. 16. 



Diagnosis. Frond narrow, linear, ancipito-compressed, distichous, 

 alternate, more or less irregulary 2-3 times pinnate, divaricately 

 branched, taking somewhat flabellate outline. Lower pinnse of stem 

 and main branches often stunted and spinose ; upper ones longer and 

 very patent, sublinear in outline, tapering to fine points, with rounded 

 axils, regularly pinnulated. Pinnules subulate tapering from broader 

 base, simple or similarly compounded, fibrilliferous at apex when young. 

 Apices of pinnae and pinnulee erect and not inrolled. Stichidia trans- 

 formed from pinnulaB, aggregated on a short pinnaa, flabeliato-dichotom- 

 ous, embracing a double row of tetraspores. Pericentral cells 6-8, 

 thickly corticated. 



Hah. On rocks between tide marks. 



Loc. This plant is rather widely distributed both along the 

 Pacific side of Hondo (i.e. the main island) and the coast of the Japan 

 sea. At present it is known from Temiya and Hakodate in Hokkaido, 

 from Iwaki in Hondo, and from Noto and Idzurno along the coast of 

 the Japan sea. 



