507 



distinguish the single species or varieties or whatever they are to 

 be cailed, but, on the other hånd, I feel equally justified in saying 

 thai there is still rauch left lo he done with reference lo Ihis sub- 

 ject, and the reason why Kjellman has failed in arriving al ;i 

 satisfactory result is doubtless because, of a great many of his 

 species, he has had an insufficient nuniher of examples for ex- 

 aminalion. 



In order to he ahle to attain lo a satisfactory result, and as- 

 certain with certainty tlu 4 variability of the different speeies, e. g. 

 with regard lo their being furnished with hooked branches or not, 

 the structure of the chromatophore, ele , il is beyond douhl neces- 

 sary to have a very large nuniher ol" specimens for examination 

 and specially from as many localities as possible, as Ihis genus, at 

 any rate along the eoasls of Ihe Færoes grows in (seen from a 

 biologicai point of view) widely different habitats, e. g. sometimes 

 in exposed and sometimes in sheltered piaces; sometimes in water 

 perleeliv salt, sometimes in brackish water; sometimes near low-water 

 mark, sometimes near high, ele., conditions which undoubtedly al- 

 leet the different individuals greatly. I am therefore of opinion thai 

 unlil we have a monograph based on a considerable material, it is 

 hardly possible to arrive at any satisfactory result with regard to 

 the systematization of this genus, consequently, I have for the pre- 

 sent preferred to leave a part of my material undelermined. 



A few years ago Wil le 1 read a preliminary paper on the cell- 

 nuclei of the Acrosiphonia in the »Biologisk Selskab« in Kristiania, 

 and in what follows I agree with Wille in referring those species 

 to Acrosiphonia which have many nuclei in each cell, but, on the 

 other hånd, as proposed by Wille, I utilize Ki'itzing's old generic 

 name of Spongomorpha for those which have one nucleus only in 

 each cell. I may add that as early as in 1898 Ros en vinge 

 pointed out in Deux. Mém. (p. 103, footnote) Ihe occurrence of one 

 nucleus only in each cell in forms resembling Cladophora lanosa. 



185. A. albescens Kjellm. 



I think a great many specimens in my material may he referred 

 tothis species. Fig. 103 shows some portions of the plant. The species 

 is specially characterized by its spiny more or less unilateral bran- 

 ches (fig. 103 a, b and f). Hooked branches also occur, but often only 

 sparingly (fig. 103 a, c and d). According to Kjell mans description 



1 Cfr. Botaniska Notiser 1899, p. 281. 



