109 



Relation to other species. The plant on the one side reminds 

 one of L. compactum and on the other side it rather approaches 

 L. incrustans f. clepressa in habit, and appears to be most nearly 

 related to this. It, however, distinguishes itself especially with re- 

 ference to the conceptacles of sporangia, which are smaller and 

 differ in several particulars. The structure also seems in general 

 to be coarser. 



Habitat. In the only locality hitherto known it appeared in 

 a shallow rock-pool at low- water mark of neap tide in a fjord, 

 but a rather exposed place. It bears mature sporangia in the later 

 half of August, partly also with such ones in development partly 

 emptied conceptacles. 



Occurrence. Only found in the neighbourhood of Bergsfjord 

 in West-Flnmarken, local and very scarce. 



Lithothamnion foecundum Kjellm. 

 N. Ish. Algfl. p. 131 (99). 

 Descr. et Fig. Lithothamnion foecundum Kjellm. 1. c. et t. 5, fig. 11 — 19. 



Syn. Lithothamnion polymorphum Kjellm. Kariska hafvets Algv. p. 15. 



Remark on the determination of the species. It scarcely ad- 

 mits of an}^ doubt, that some few specimens gathered in East- 

 Finmarken belong to this species, although I have not succeeded 

 to find the sporangia. One of them, however, bears conceptacles 

 of sporangia, which at least in part are almost fully developed 

 and exactly coincide with a couple in a fragment of an authentic 

 specimen from the Kara Sea. However, it appears as if they are 

 rather differing in the different states of development, and the 

 border is often to be seen only in a certain state, but I have not 

 been able to get any clear idea of their development in the scanty 

 materials at my disposal. Emptied conceptacles apparently not 

 seldom get filled by new local formations of tissue, judging from 

 such ones seen on a radial section together with overgrown con- 

 ceptacles. The specimens otherwise also agree well with the 

 description and the named fragment. The peripherical portion of 

 the crust is feebly concentric zonated, and the whitish brim rather 

 indistinct. 



