10 



really belongs to the Chordarleae, and, In Till algernes Systematik 

 p. ^6, Prof. J. G. Agardh, judging from the structure of the 

 frond, suggested that it probably belonged in Sporochnoidere near 

 Nereia. The uniform distribution of the sporangia over the 

 whole surface of the frond, not in verrucaeform spots, shows how- 

 ever, that it belongs in Chordarieae and not in Sporochnoideae. But 

 It is not so easy to decide upon the exact genus in which it should 

 be placed, for algologists differ widely as to the limitation of the 

 genera of Chordarieae. The axis is composed of filaments of 

 large cylindrical cells closely packed in the upper and younger 

 parts of the frond which, in the lower part, becomes hollow with 

 age. From, these larger, colorless filaments are given off smaller 

 filaments, which make their way to the surface of the frond where 

 they ramify irregularly and from them are given off at right an- 

 gles tufts of short, brownish filaments, which form the cortical 

 layer. The latter are moniliform, at first erect, later somewhat 



recurved over the unilocular sporangia which are formed at their 

 base. 



Although the genus cannot be absolutely settled until the 

 trichosporangia are better known, there being no indication of 

 the secund outgrowths of the cortical filaments which mark the 

 genus Castagnea, nor of the discoidal cells characteristic of Clad- 

 osiphojt as limited by Prof. Agardh, 1. c, p. 8, our plant must be 

 referred either to Mesogloia or Myriocladia. Writers difTer very 

 much as to the distinctions between the two genera. According 

 to Agardh, those species are placed in Myriocladia which have 

 filaments that project beyond the cortical layer, and in which the 

 cortical filaments in which the trichosporangia are formed, become 

 moniliform. tapering at both ends. As far as the cortical filaments 

 are concerned, MJ Andersonii does not agree in structure with 

 Myriocladia. The exigence of filaments which project beyond 

 the surface of the frond is the only mark which would lead one 

 to refer it to Myriocladia. They, however, are only found in 

 certain stages of growth, and in my specimens preserved in alco- 

 hol, are not to be seen, although they are to be found in a few 

 young, pressed specimens. 



Judging from published figfures. M. And^r^n,,;; U rU^^Ur r^. 



*Lunds Univers. Arsskrift, Vol. x.xvii. 



