441 
ASPEROCOCGUS Lamx. 
131. A. echinatus (Mert.) Grev. 
This species has hitherto been found only by Simmons in 
Kvalbofjord (Syd.), where it grew epiphytic on Corallina officinalis. 
Fructifying specimens were found in August. 
PHiEOSTROMA Kuck. 
132. Ph. parasiticum nov. spec. 
In preparing a large Laminaria fceroensis which had been pre¬ 
served in salt I observed on the lamina some small, dark brown 
patches which on closer examination proved to be an interesting 
brown alga which appears to me to be referable to the above- 
mentioned genus, and Dr. Kuckuck, to whom I showed my draw¬ 
ings while in Heligoland, was of the same opinion. Unfortunately, 
I can only give a very imperfect description of this plant, as having 
been preserved in salt the cell-contents were quite destroyed, and 
the material, moreover, proved to be unfit for dissecting purposes, 
so that, it has been impossible to obtain good, thin slices. But 
the plant is so characteristic that it will be easily recognized in 
spite of the imperfect description. 
As mentioned above, the alga forms dark brown patches on 
the lamina. On examining these patches more closely the margin 
will be found to consist of richly branching, free filaments (fig. 83, 
b and c) which towards the centre gradually grow together and the 
one above the other, forming a pseudo-parenchymatous tissue, 
frequently of considerable thickness (fig. 83 d). In a transverse 
section this tissue again will be seen to grow out in the middle of 
the plant and to extend into the lamina of the Laminaria through 
the epidermis of the latter, going further down between the large 
cells and finally spreading radiately in the hyphse-layer in the 
centre of the lamina. 
The margins of all the specimens I examined were invariably 
composed of free filaments, and usually they could be distinctly 
traced far towards the centre of the plant; but a disc with mar¬ 
ginal growth such as Kuckuck has figured under Ph. pustulosum I 
did not meet with on my plant. The cells in the main branches 
are generally 3 to 4 times as long as broad, and the main branches 
frequently bear opposite ones. I did not come across horizontal 
walls separating the filaments into two layers such as most fre- 
