441 



ASPEROCOCCUS Lamx. 



131. A. echinatus (Mert.) Grev. 



This species has hitherto been ibund only by S i ni mon s in 

 Kval 1)6 fjord (Syd.), where it grew epiphytic on Corallina officinalis. 

 Fructifying specimens were found in August. 



PHÆOSTROMA Kuck. 



132. Ph. parasiticum nov. spec. 



In preparing a large Laminaria færoensis 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 l)r. Kue kuck, 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 hyphæ-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 lavers such as most fre- 



