757 



Floridea\ It is the haptera and especially the stalk which are almost 

 densely covered by large or small algae (see tig. IGl). The lamina 

 liowever is mostly destitute of epiphytes, most likely because it is 

 changed every year. Various species, however, e. g. Rlwdijmenia 

 palmata, Edocarpiis tomentosoides, which would probably be very 

 common in spring, E. tomentosiis , E. fasciciilatus, and some others, 

 may be found growing on the lamina, especially in shallow water. 



Among the many epiphytes that grow^ on the stalk and the 

 roots, the following species may t)e pointed out: Polijaiphonid nr- 

 ceolata, Chantransia Daviesii, CallophijUis laciniata, Euthora crisUiht, 

 Rhodophijllis dichotoma, Lomentaria cUtvellosa, L. rosea, Plocamium 

 coccineum, Delesseria alata, D. siniiosa, D. sangiunea, Pohjsiphonid 

 elongata, Odoiithalia denkda, PtUota plumosa, Pt. pectinata, Aniitham- 

 nion floccosiim, Ceramium riibrum, Rhodochorton Rothii, Criioria pel- 

 lita, Lithophylliim Croiiani, Dermatolithon macrocarpiim f. Laminarkc, 

 Peyssonelia Diibyi, Sphacelaria furcigera, Desmarestia aculeata, D. vi- 

 ridis; that is to say, scarcely any but Floridece. Most of these epi- 

 phytes may be found even in rather shallow water in the semi- 

 darkness under the Laminarice which also afford some protection 

 from the violence of the waves. 



In describing the algae-vegetation of the Mediterranean Sea, Ber- 

 thold points out (5, p. 422) that the epiphytes on a Cystosira granii- 

 lata grow in a certain fixed order. Those that require more light 

 grow^ on the top of the Cystosira, those that want less grow under 

 the latter. The epiphytes on the stalks of the Laminaria hyperborea 

 likewise grow^ in a certain fixed order from the top downward, 

 according to the degree of light required by each alga; those that 

 want much light grow uppermost, the others low^er down. The 

 colour of the water can hardly be of any consequence where the 

 distance from the top to the bottom only means the length of the 

 stipes. At the top of the stipes we find Ceramium riibriim, Poly- 

 siphonia iirceolata, Delesseria alata, Polysiphonia elongata, and from 

 these algae downward, we find Odonthalia dentata, Delesseria siniiosa, 

 Plocamium coccineum, Ptilota plumosa, Lomentaria clavellosa, Sphace- 

 laria furcigera, Rhodochorton Rolhii, Criwria pellita, Dermatolithon 

 macrocarpiim f. Laminarice etc. On the lowest part of the slipes, 

 and especially on the haptera, Callophyllis laciniata, Rhodophijllis di- 

 chotoma and Euthora cristata are found. 



The Laminaria hyperborea-SLSSOc'iSLi'ion reaches its finest develop- 

 ment in the course of the summer. The lamina is changed in winter, 



