252 'J^tlE BOTANICAL MAGAZINE. LVoi. xxx. No. 355. 



Dilophus flabellatus Collins. 



ill Pliyc. Bor.-Anicr., No. 8o4-.— Collins: New Species in Pliveo- 

 llicea, p. 108. 



= Dictyota marginata Okam.: Icon. Jaj), Alg., Vol. Ill, I'l. 108, 



^<y. 9, PI. 109. 

 = Dilophus marginata Okam. (noii J. Ac): Icon, Jap. Alg. \'ol. 

 Ill, PI. 154. 

 ? = Dictyota proli'/icans A. and E. S. Gurr: Some New Mar. Alg. N. 

 S. \Yales, p. 250, PI. 481, fig. 2. 



Okamuk.\ described a ])1 iiit from Japan with full illustration 

 as a new, callinu^ it Dictyota marginata. The plant showed the 

 very characters of Dilophus J. Ag. The establishcr seems to have 

 noticed it soon after the publishment as he transferred the 

 species to Dilophus in the "corrigenda" in No. 7. of his Icones. 

 He left the sjjecific name unaltered, noting that "of the differ- 

 ence c)f this ])lant and Dilophus niarginatus J. Ag. I can not 

 state anything unless I could study our plant by comparing 

 with that plant of the author." 



Okamura's plant agrees with D. Hahellatus Collins in all 

 respects so that there is no doubt left on the identity of the 

 two. lie describes his ])lant to have more or less stupose base 

 and also that there are given rise many filiform stolon-like 

 segments from both sides of stem. Collins points out the 

 difference between his plant cind D. marginatus J. Ag. as the 

 latter is not stupose biit is attached by a growth of rhizoids, 

 while the former has the base stupose for a short distance. 

 Consulting the descriptions given i)y the two authors and with 

 s])ecimens of Japanese Dilophus laid before mc, I am (juite certain 

 that Okamuka's ])lant may be a])])lied to the statement "fronde 

 ca;spitosa radiculus eniissis radicante" as given b\' J. Agardh 

 in defining D. marginatus. As far as I coidd observe in my 

 specimens, numerous young shoots start from ihc base of frond, 

 and some ones from the mrirgins of complanated ])art of stem 

 near the root. Hence, a young frond may l.'c well described as 

 either Ctes]Ditosc or midticipital In some specimens the basal 

 part of frond is stupose tor a short length and in others entirely 



