512 
the apex; the top cell is short. The cells are about as long as 
broad, sometimes somewhat shorter, sometimes somewhat longer. 
In the fully developed plant the main branches grow thinner to¬ 
wards the apex (fig. 104 a and b). Lateral branches, and often even 
the main ones, terminate in thin prolongations resembling rhizoids 
(fig. 105 a); rhizoids growing downwards, occur frequently and most 
abundantly in the basal portion of the plant (fig. 104). The tips of 
the rhizoids are often palmately cleft and serve as holdfasts (fig. 
105 c). The hole through which the zoospores escape is fairly large 
(fig. 104 b). 
This plant grew between tide-marks on a rocky, exposed coast, 
where it occurred on the rock as a matted, dark-green growth, 
3 — 4—5 cm . in height. 
Fruiting specimens were found in June. 
The present plant appears to agree fairly well with Acrosiplionia 
ftagellata Kjellm., but it also comes near to Acrosiphonia cincinnata 
(Foslie) Kjellm. in many respects. 
It was gathered on Store Dimon (!). 
An Acrosiphonia which, in association with Enteromorplia- species, 
Chcctomorpha tortuosa , etc., formed large, felted growths near Klaksvig 
was somewhat similar to this plant. 
189. A. flaccida Kjellm. 
A single gathering appeared to agree fairly well with Kjell- 
man’s description of the plant he calls A. flaccida. . Both spiny 
and hooked branches were absent. The chromatophore was finely 
reticulate, with numerous pyrenoids. The cells were up to 200 
thick, i. e. somewhat thinner than recorded by Kjellm an. My 
specimens were unfortunately yet sterile. This species appears to 
come very near to Acrosiphonia hgstrix (Stromf.). 
The gathering was collected in shallow water near Thorshavn in 
the beginning of June (!). 
Acrosiphonia centralis Kjellm. is recorded from the Faeroes 
by Simmons, but a dried specimen of his plant gathered at Naes 
(Ostero) which I examined appeared to be identical with A. albescens. 
And the same appears to me to be the case with a plant gathered 
by Rostrup and called by him Conferva arcta f. centralis Lyngb. 
Nor have I found any specimens in my own material which I 
have felt justified in referring to A. centralis as it is described by 
Kjellm an, and I cannot help entertaining some doubt as to the 
