48 



M. Foslie. 





that species, and this is not seldom the case. In my coUec- 

 tions I have specimens which, as far as I am able to judge, 

 may be referred to either of these two spedes. 



The plant is sublitoral, occnrring partly in the upper 

 part of the region, on a depth of 2—5 fathoms, partly on a 

 depth of about 15 fathoms. It prefers exposed localities and 

 has not been met with in the deeper bays, usually growing 

 scattered, attached to shells ofBalanidæ, Uthothamnia, Bho- 

 dophylUs dichotoma, Ptilota plumosa and pecUnata. Specimens 

 bearing tetrasporangia, but sparingly, have been coUected at 

 KjoUefjord in the middle of June; at Mehavn in the begin- 

 ning of July, also sparingly (f. coralUna); at Berlevaag in 



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the middle of July, rather ricWy; and at Kjelmo in Sydvar- 

 anger in the beginning of August, very sparingly. 



Some specimens collected at Kjelmo are densely over- 

 grown with small cysts with oily contents, probably Ohj/^ 



tridium plumulæ C o h n. 



Distribution: Scattered and in general very scarce along 

 the unsheltered coast; rather common on an iron buoy at 

 Berlevaag (f. typka). A few specimens of f. corallina found 

 at Mehavn, and at Kjelmo a transition between this form 



and f. typica. 



j 



I 

 \ 



I 





G-en. Rhodochorton Nag. 



Cerauu p. 121, 



Subgen. 1. Thamnidium Thm\ 

 in Le Jol. Liste Alg. Cherb* p. 110. 



Rhodochorton Rothii (Turt.) Nag. 



Ceram. p. 121; Conferva Rotlui Turt. Syst. 6, p. 1806, sec. Dillw 

 Btii tonf. t. tå. 



■Beser. Callithanmion Rothii J. G. Ag. Epicr. p. 13, 



'!Fig\ Thamnidihm Eothii Thur. in Le Jol. Liste Alg. Cheib. t. 5. 



'Exsicø» 



» 



Aresch. Alg. Scand, exsicc. No. 259. 



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