507 
distinguish the single species or varieties or whatever they are to 
be called, but, on the other hand, I feel equally justified in saying 
that there is still much left to be done with reference to this sub¬ 
ject, and the reason why Kjellman has failed in arriving at a 
satisfactory result is doubtless because, of a great many of his 
species, he has had an insufficient number of examples for ex¬ 
amination. 
In order to be able to attain to a satisfactory result, and as¬ 
certain with certainty the variability of the different species, e. g. 
with regard to their being furnished with hooked branches or not, 
the structure of the chromatophore, etc., it is beyond doubt neces¬ 
sary to have a very large number of specimens for examination 
and specially from as many localities as possible, as this genus, at 
any rate along the coasts of the Faeroes grows in (seen from a 
biological point of view) widely different habitats, e. g. sometimes 
in exposed and sometimes in sheltered places; sometimes in water 
perfectly salt, sometimes in brackish water; sometimes near low-water 
mark, sometimes near high, etc., conditions which undoubtedly af¬ 
fect the different individuals greatly. I am therefore of opinion that 
until 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 undetermined. 
A few years ago Wille 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 hand, as proposed by Wille, I utilize Kutzing’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 Rosenvinge 
pointed out in Deux. Mem. (p. 103, footnote) the 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 be referred 
to this species. Fig. 103 shows some portions of the plant. The species 
is specially characterized by ils 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 Kj ell man’s description 
1 Cfr. Botaniska Notiser 1899, p. 281. 
