— 100 — 



the Tightness of this opinion. If the true C. strictum is another species 

 different from my form, this should be named with a new name. 



It is not impossible that the form corticatulo-stricta of C. dia- 

 phanum described by Kylin is in reality a form of my C. strictum, 

 this species perhaps occasionally being able to form zones which 

 grow upwards. 



I cannot finish the mention of these two species without drawing 

 the attention to another possible difference between them. I have 

 namely observed the Phycomycete Pontisma lagenidioides (1905, 

 p. 482) as parasite only in the typical individuals of C. strictum, 

 not in the strictoid forms of the C. diaphanum. 



Ceram. Areschougii Kylin. 



In Kattegat near Frederikshavn I have found specimens of 

 Ceramium in morphological respect related at the same time to C. 

 rubrum and C. Areschougii. In my paper 1908 I have intimated 

 that these specimens probably should be regarded as belonging to 

 C. rubriforme Kylin. The author of this species who has examined 

 some of the specimens in question, still is of opinion that they do 

 not belong to this species, which is more related with C. arborescens. 

 Thus there is no alternative but to assume that they belong to C. 

 Areschougii in particular as they are in conformity with this species 

 in the presence of réfringent bark-cells containing proteid-matter. 

 Yet they seem to be furnished with these cells in greater extension 

 than the typical form. This new form differs from the typical one 

 in the ramification, which often is not dichotomous, in the stronger 

 development af bark with rather few hyaline interstices in the 

 upper parts, in the often incurved apices. It is conform with the 

 typical form in the colour (it differs in this point from C. fruticu- 

 losum which is more rusty red), in the structure of the zones and 

 the occurrence of réfringent cells in the bark. 



These cells (Fig. II) occur sparingly in the upper part but are 

 common in the middle and lower parts. They are differently 

 formed in shape of the ordinary barkcells or more or less reniform 

 and usually lie in the outermost layer. The contents are usually 

 slightly remote from the membrane of the cells and consist of a 

 sometimes homogenous more or less vacuolized sometimes finely 

 spumous, (by slightly magn. it appears granulated) sometimes lumped 

 always réfringent protoplasm with more or less conspicuous 

 nucleus usually without chromatophores and starch. So far I can 

 see these cells are formed of the ordinary cells by early loss of 



