— 99 — 



able because the typical forms in very little extension are suitable 

 to divisions of the bark-cells while the typical forms of C. dia- 

 phanum often in degree show a reduction of the bark 1 ). As to 

 the bark these two species are well defined. But in morphological 

 respect they can be much alike and probably these forms which 



Fig. I. 



1 : C. diaphanum with bark with character of C. strictum (zone from the lower parts) ; 2 and 3 : C. 

 strictum (2 from the middlemost, 3 from the lover parts); 4: C. diaphanum (zone from the lower parts). 

 1 and 2 x c. 425 ; 3 and 4 X c. 400. 



are intermediate have been included in the original C. strictum. 

 But probably forms as the Danish have also been included in this 

 species. The diagnosis of J. G. Agardh. in Spec, gen et ord. algarum 

 Vol. II of var a: zonis geniculorum angustissimis seems to indicate 



] ) At Hellebæk on the north-east-coast of Sealand both species occur, the 

 strictiform forms of C. diaphanum together with C. strictum. But no 

 transition was observed. 



7* 



