454 
Further, in some cases a feebly differentiated cortex may occur. Neither does the differ- 
ence in the season of fructification emphasised by KyLın seem to give a decisive 
mark, for both species were found with sex ofgans 
in January and were frequently found with ripe 
sporangia in April and May in the Danish Waters. 
In the inner waters, particularly the Baltic Sea, 
a fine form appears which in its extreme shape 
is very marked but which on the other hand is 
nearly related to the typical Rh. subfusca and to 
Rh. virgata as well. It is remarkable by its very 
thin and slender shoots and may be referred to 
f. tenuior Agardh, especially as it is characterised 
by SVEDELIUS (1. c.). In the ramification it usually 
resembles Rh. subfusca, the long branches bear- 
ing a considerable number of branchlets which 
Fig. 414. are not shed, whereas in the anatomical structure 
ln NOS ee DE it agrees better with Rh. virgata (comp. SVEDELIUS 
1901 p. 125). 
Another thin and slender form &, abyssicola nob. was gathered in the southern 
Little Belt south of Lyo in 22 meters’ depth. Some of the specimens resembled Rh. vir- 
gata in habit (Plate VI fig. 2), others had a very thin principal axis and very distant 
thin and slender branches which were only slightly branched, in particular towards the 
top (Plate VI fig. 4). The trichoblasts were kept at least 4 cm below the top. These plants 
were still fructiferous on June 20th and bore sporangia and cystocarps in elongated 
branchlets not different from the vegetative 
ones, thus behaving much as Rh. subfusca. 
A section of the main stem shows the 
same structure as in Rh. virgata, but the 
cells are smaller. The diameter of the stem 
was 320 w (fig. 414). The plants are red 
and keep the colour when drying. 
All the forms mentioned are thus 
here considered as forms of Rh. subfusca 
which may be divided in the following 
principal forms: 
&, genuina. 
8, lycopodioides (L.) Gobi. Fig. 415. 
> virgata (Kjellman) nob. Rhodomela subfusca growing on Portunus. Basal dise 
. . 2 : with primary and secondary shoots. 38:1. 
0, tenuior (C. Agardh) Svedelius. ep: 2 
e, abyssicola nob. F. axi primario distincto tenui, ramis remotis longis, parce 
præcipue apicem versus ramosis, trichoblastibus diu persistentibus. 
