

Isthmoplea rupincola, 



a new Alga. 



By 



M. F o sli e 



I collected last summer at Kjelvik in West-Finmarken 

 an alga, which is nearly related to the hitherto known sing- 

 le speeies of the genus Isthmoplea, but, as it in many re- 

 spects differs from that one, I sphærophora, I cannot but 

 hold it to belong to another speeies. It grew gregariously 

 in small number on rocks in the upper part of the litoral 

 region in a rather mach exposed locality. 



The plant forms small tufts 3—8 cm. in height of a 

 dark olive-brown colour, in dry ing getting a little lighter 

 and sometimes inclining to rusty brown. The tufts are com- 

 posed of numerous, especially in the lower part of the frond 

 narrow and more as less densely twisted bundles. Dried 

 specimens bear a striking resemblance to certain forms of 



Pylaietta compacta. 



The basal part of the frond agrees, as far as I have 

 seen 1 , with that of I. sphærophora as described by Kjell- 

 man in Handbok, p. 81. 



. The plant is described from dried specimens afterwards softened iia 



l 



water with addition of Eau de Javelle. 



