112 THE BOTANICAL MAGAZINE. tvoi. xxix. No. sir. 



individual and shall never be put too much importance in the 

 specific distinction. Comparing the specimens under the section 

 Thamnocarpus J. Ag. in the Agardhian Herbarium, I can not 

 but come to the conclusion that all the species under the sec- 

 tion, except some doubtful ones, belong to one and the same 

 species. And also, the originals of P. angustum are not separ- 

 able from some of the specimens of P. rigidum Bory in the 

 Agardhian Herbarium. The latter are not uniform in the im- 

 portant characters and as there lacks any authentic specimen 

 from Bory, I am in no less hesitation to treat P. angustum J. 

 Ac. as an valid species. The specimens distributed by Harvey 

 under that name as No. 357 of the Australian Algae are noth- 

 ing but a narrow form of P. Telfairiae Harv. with the indefi- 

 nite branches not full}- developed. 



Specimens of P. brachiocarpum in the Agardhian Herbarium 

 have one definite (pinna primaria) and one indefinite branch 

 strictly alternate. But Kutzing's species is diagnosed to have 

 the pinnae " ternis— quinis " and the illustrations in Tab. Phyc. 

 XVI, Taf. 51, fig. a-b, agree with the definition. 



The specimens of P. nohile J. Ag. are also hard to draw 

 any sharp boundary to separate with J. Agardh's P. brachio- 

 carpum. Cottox reported a plant under the former name from 

 a material collected in Corea. His plant seems also to ap- 

 proach P. brachiocarpum J. Ag. 



Comparison of specimens of P. abnorme and P. Telfairiae in 

 the herbarium of the Trinity College, Dublin, proves the former 

 a narrow form with less developed indefinite branches of the 

 latter. 



Okamura proposed a new forma under this species in his 

 Icones of Japanese Algae, pi. CII. The recurved and uncinated 

 ramulets are mentioned to characterize the forma. This charac- 

 ter, however, is not at all specific or formic as we often meet 

 such a form which has an upper portion of a frond provided 

 with uncinate definite branches, while in the lower parts the 

 t\ r pical form of P. Telfairiae is shown. His new species P. re- 

 curvatum is simply a form with the said character much more 

 pronounced. I have several specimens which have the upper 



