— 110 — 



Iceland : 



Some specimens collected by H. Jonsson on Grötta (S. W. Iceland), 17 /e 

 1900, provided with antheridia seem to belong to this species. 



According to the here communicated informations (notes of 

 Dr. Børgesen) this species no doubt is confined to the littoral zone. 

 Several of the specimens are very regular, probably because they 

 are developed in quiet water. 



Ceram. septentrionale sp. nov. Pl. V, fig. 26. Fig. II, III and IV. 



Ramificatio dichotoma vel irregularis, non characteristica. For- 

 cipes sæpe asymmetricæ apicibus rectis. Numerus cellularum 

 axialium sæpe rnagnus usque ad 30. Cortex in partibus superiori- 

 bus confluens. In partibus intermediis zonæ, quarum aliæ struc- 

 tura earum in Ger. Rosenvingii, aliæ et vero plurimæ structura 

 earum in Cer. fruticulosi, occurrunt. In partibus inferioribus cortex 

 numquam confluens zonis semper distingvendis. Fructificatio ignota. 

 Color atropurpureus. In maribus apud oras Groenlandiæ occiden- 

 talis et Spetsbergenses. 



The ramification is dichoto- 

 mous or irregular with develop- 

 ment of main axes, not characte- 

 ristic. The forcipes are often un- 

 sym metrical with straight apices ; 

 the thickness of the axes very 

 slowly decreasing. Often a great 

 number of axial cells in each 

 internodium (up to 30). The 

 bark is in the uppermost parts 

 continuous. Below this part 

 we find firstly zones which are 

 sharply confined (cf. fig. II). In 

 the middlemost part the case 

 seems to be thus that some specimens are furnished with zones 

 which partly resemble those of the C. Rosenvingii-arborescens- 

 group (fig. Ill), while others 

 are furnished with such which 

 show signs of relationship to 

 the group of C. fruticulosum 

 (fig. IV). In the lower parts scar- 

 cely any distinct* confluence of 

 the zones takes place. In few 

 cases barrel-shaped axial cells m - 



_ _ xi i li • • & septentrionale; lower margin of an older zone 



are fOUnd SO that thlS Species character of C. Rosenvingii. x c. 385. 



Fig. II. 



C. septentrionale: a younger zone 



