KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 113 



In summer the plant always presents an aspect of this kind. J. E. Areschoug 

 in Alo'. Scand. Exsicc. Ser. 2. N:o 57 has distribnted such speciinens, collected in August. 

 Only exceptionally one finds some speciinens of tliis kind during Avinter. 



The plant in lointer habit. During winter and tlie earlier part of spring the plant 

 has the appearance shown by fig. 2 and produced by all the elements of ramification 

 being raore or less completely dissolved. The elements 1 and 2 are most strongly re- 

 sorbed. Specimens of this kind are very common on the coast af Bohuslän in winter 

 during the months of December and January. 



The plant in sprimj habit. Fig. 3. Cp. Aresch. Alg. Scand. exsicc. Ser. 1. N:o 54. From 

 the portions that have persisted through the winter, branch-systems, sometiuies scattered, 

 sometimes somewhat tufted, are developed, which produce sporocarpia and tetrasporangia. 

 These systems are decompound, with a corymbose development, and in this species attain 

 a more considerable size before the ripeness of the spores, than in the preceding one. 

 I do not know any antheridia in this species. I have taken specimens with ripe sporo- 

 carpia in May, with ripe tetraspores in April. 



The structure of the frond. The figures 4 and 5, both representing sections of the 

 lower part of the frond, shoAv that outside the siphons there begins a raighty layer of 

 large-celled parenchyma, sharply defined without against a small-celled layer of tissue, 

 that is also raighty and passes Avithout marked limit into the cortical layer. All cell- 

 walls are thick. The large-celled parenchyma is destitute of or poor in endochrome, 

 the small-celled is rich in endochrome. 



It is evident, that of these tAvo species Bh. virgata has nothing to do with Rh. 

 lycopodioides. Rh. siibfusca, on the contrary, presents so great a resemblance to certain 

 forms of this species, especially f. typica /t läxa, that it may be questioned Avhether 

 they are indeed specihcally distinct. Both have very often been confounded Avith each 

 other. All the specimens of the so-called Rh. subfusca, brought home by Kleen from 

 Nordlanden and come under my notice, are undoubtedly forms of Eli. lycopodioides; 

 and that plant from the coasts of Spitzbergen, Avhich I have mentioned under the narae 

 of Rh. siil>fuf!ca, I must now alloAV to be a form of Rh. li/eojjodioides. Many instances 

 of that kind might be quoted. On that account, one might be inclined, like Gobi, 

 to uiiite these tAvo Rhodomehe and to regard Rh. subfusca as a southern form of the 

 other. But, on the other hand, it is remarkable, that both the forms occur quite cha- 

 racteristical on the coasts of England, and that on the coast of Sweden Rhodomela 

 subfusca, in Avhatever localities it may groAV, Avhether near the surface or in deep 

 water, is constantly alike in form, and, above all, never appears here in any densely 

 branched comi^acta- or densa-iorm; whereas Rh. lycop)odioides on the coast of NorAvay, 

 Avhen growing betAveen tide-marks, exhibits regularly the form typica, compactn, but in 

 other cases assumes readily the aspect of f. typica />' läxa, Avhich proves that these tAvo 

 species or forms vary in a difterent manner. I must, moreover, call attention to a 

 difference betAveen them, Avhich, as far as my researches go, has shoAvn itself to be 

 universal and constant. Rh. lycopodioides, in Avhichever of its numerous and extremely 

 variable forms it maj' occur, always benrs on its more robust axes short, slightly boAV- 



15 



K. Vet. Akad. Handl. Band. 20. N:o 



