July, HM.i.] YJCNJW.—NOTKS ON AhGJE NEW TO JAPAN, V. 251 



Under what j^^enus should this interesting pL'int be placed is a 

 question still undecided among algologists. J. Agakdii brought 

 this species in a synouA'mous position luider his Elachista 

 adrmtica. De Toni enumerates the latter, though with hesita- 

 tion, as a second species of Alyriactis, l)ut entirely following J. 

 Agardh in synonymizing ])revious described other s]jccies under 

 it. I am but to accept Hauck's view to place the present plant 

 under Leathesia, reserving, however, a question on the generic 

 limitation for future. 



The specific arrangement as done by J. Agardh in Till Alg. 

 System., II, p. 21, appears to be inadequate. This is understood 

 from a highly interesting letter sent from Hauck to J. Agakdii 

 just after the publication of the mentioned work, now kept in 

 the Agardhian Herbarium with the type specimen of Elachista 



adriatica. In it Hauck says: — " Audi fand ich Cor. flaccida 



Kg. nur aui Chaetomorpha, Cladophora, Zostera, nie auf Cysto- 

 seira. Auf dieser kommen hier nur Elachista pulvinata (selten) 

 und Corynophlxa umheUata Kg. (sehr haufig) vor. Die peri- 

 pherischen Faden von Cor. umheUata Kg. sind abcr immcr 

 keulfcirmig nie beiderends verdiinnt. 1st diese Alge nun auch 



identiseh mit Hirer E. adriatica'^ " Hauck referred to Till 



Alg. System., II, p. 21, in describing the present species in his 

 Meeresalgen, though without mentioning the name E. adriatica. 

 It is very probable that he has done so as he had received an 

 answer from J. Agardh for the letter. The view held b}- Hauck, 

 who, as an eminent algologist, sat in a more favourable position 

 than any other to study KIjtzing's originals, and to examine the 

 plant in living state, of the present species, is to be esteemed 

 wath greater value. 



Our ])lant is found copiously on the vesicles of Sargassuni 

 Kjellmanianum and is hitherto know^n with unilocular sporangia 

 only. Apparently similar plant, with assimilators nearly homo- 

 geneous in diameter for the whole length, and closely resembling 

 to Myriactis pulvinata but not identical to it, is always found 

 associated with the present species. 



Locality. Oshoro (!). 



Distribution. Adriatic Sea. 



