KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 61- NtR Ii. 31 



has not been possible to identify the Chordaria, the alga here is left under the old 

 name Ccepidium.» But, under Colpomenia sp. Cotton remarks 1. c. p. 179: »The forked 

 basal branches described by Skottsberg would appear to be part of the Colpomenia 

 plant (and not of the Chordaria), and these are unlike anything found in the ordinary 

 Colpomenia of Europé >. Further: »Pending further investigation of preserved ma- 

 terial I have left the plant as Colpomenia sp. » Thus, Cotton here seems to accept 

 my view that the solid branches and the vesicles belong together, but thinks that 

 they represent a species of Colpomenia. I hope that I have made it clear this time 

 that it is not Colpomenia sinuosa, nor an allied species. Colpomenia belongs to the 

 Encoeliacese, and the anatomical structure is essentially the same as in Scytosiphon, 

 Punctaria, etc. Unfortunately, no young stages of Colpomenia are known, but Prof. 

 Kuckuck was of the opinion that it is polysiphonous, i. e. that tangential divisions 

 occur, which is not the case in the Chordariacese. I have examined C. sinuosairom 

 Juan Fernandez, Puget Sound and Ceylon; all have the same structure, well illustrated 

 by Börgesen in Mar. Alg. Dan. West Ind. Pt 2, p. 176. There is a much sharper 

 limit between the cortex and the inner layers of very large cells than in Ccepidium. 

 The latter has no distinct sori, and the formation of gametangia stånds in no 

 relation to the hairs, which are solitary in Ccepidium and not grouped together in 

 cryptostomata. Finally, the sterile cells in Ccepidium are rather unlike the paraphyses 

 (or assimilators of Oltmanns, Biol. u. Morph, Meeresalg. Il p. 375). Taking all the 

 differences into consideration, the likeness between the two plants appears quite 

 superficial, and it is evident that the bladder-bearing Ccepidium is not a species of 

 Colpomenia, nor a member of the same order. I admit that this is no proof of its 

 belonging to the Chordaria-bearing Ccepidium. But the two plants are so absolutely 

 alike as to the appearance and structure of the horizontal thallus that I refuse to 

 regard them as belonging to two distinct genera. 



Distribution: Fuegia, Falkl., S. Georgia, Kerg. 



Stereocladon Hook. fil. et Harv. 



S. rugulosus (Bory) Hariot. — Fig. 13 c— g. 



Falkland Islands: Port Louis, frequent on Mytilus in the lower litoral 

 region (St. 11, 7. 2. 08, sp.). — The expanded crusts carry numerous stumps of old 

 erect shoots in the centre and younger ones nearer to the margin, new ones devel- 

 oping during the summer months. 



Hariot, Miss. sci. Cap Horn p. 41 places Stereocladon among the Chordariacese 

 without further discussion. Most authors have referred it to Scytothamnus. In the 

 externat appearance of the erect fronds there is no great difference, but a closer 

 examination clearly justfies the reestablishment of the genus Stereocladon. It pos- 

 sesses a large horizontal thallus, from which spring the erect fronds, a dimorphism 



