524 



As mentioned above it grows as an epiphyte on Polysiphonia 

 fastigiata, and like Dermocarpa prasina it occurs in small, roundish, 

 almost semi-globular growths, or when several such grow together, 

 in cushion-like expansions, irregularly shaped. In a Iransverse sec- 

 tion, or, better still, on separating the cells by means of a gentle 

 pressure, they prove to be (fig. 108) cylindrically club-shaped, nar- 

 row at the bottom and widening upwards to the lop, and with 

 homogeneous contents of a bluish-green colour. The cells are about 

 60 — 90 // long and about 30 /< broad. The entire contents of the 

 cells are transformed into a very considerable number of small 

 conidia ; the latter are about 2,5 // broad. As may be seen from 

 Ihis description the present plant differs essentially from D. prasina 

 in having larger cells and inuch smaller conidia. 



Conidiiferous specimens occurred in May. 



Found hitherto only on Syd.: Tværaa (!), 



205. D. violacea Crouan (?), Algues marines nouvelles de la rade 

 de Brest. (Anm. se. nat. IV Ser., Bot., IX. 1858, p. 70). 



Epiphytic on Ralfsia verrucosa which grew on exposed rocks 

 in the sea. I found a very small quantity of a Dermocarpa which 

 I refer very doubtfully to D. violacea. The cells are pear-shaped, 

 and the cell-contents of a yellowish-brown colour, sometimes faintly 

 blue-green. The entire contents of the cells are produced into co- 

 nidia, which are about 1,5 — 2 n in diameter. The cells are 24 — 30 (i 

 long and as much as 16 \i broad. It differs more particularly from 

 Crouan' s description by its different colour and by its conidia 

 appearing to be somewhat smaller. 



Found on rocks in the sea oli" the north-west point of Videro(!). 



PLEUROCAPSA Thur. 



206. P. amethystea Rosen v. var., Jobs. Schmidt 1 . 



Found epiphytic on Rhodochorton Rothii, consequently, in the 

 same habitals as the latter. It has been found on almost all the 

 material of Rhodochorton brought home and must therefore be re- 

 gn rded as common along the coasts of the Færoes. 



1 Tliis variety \v:is determined by Mr. Johs. Schmidt whose notes on it will 

 appear in Helgi Jonssons paper »The Marine Algæ of Iceland« in »Botanisk 

 Tidsskrift . 



