KONGL. SV. VET. AKADEMIENS HANDLINGAE. BAND. 20. N:0 5. 309 



Remark on the determination of this species. I hold it to be beyond a doubt that 

 the alga which I understand by the above name, is identical with that described and 

 figured by the authors quoted under the names of C. gracilis and C. vadorum. Though 

 approaching nearly to C. glaucescens, it differs from it by essential characteristics. Its 

 relation to the plant commonly called C. gracilis by Scandinavian algologists and dis- 

 tributed by me under N:o 119 in Wittr. et Nordst. Alg. exsicc, is a question I can- 

 not decide at present. That plant differs much in its habitat from the present species. 



Habitat. On the polar coasts I have always found this alga in hollows filled 

 with water on gravelly shores. It is attached at first and it then presents its typical 

 aspect. When older, it forms loose intricate masses, exhibiting very little resemblance 

 to a typical C. gracilis, as has been correctly pointed out by Farlow 1. c. In this 

 condition it rather agrees with C. crispata as delineated by Kutzing, Tab. Phyc. 4, pi. 

 40, fig. 1 A. Kleen says that he found it attached to other algsB in the upper part 

 of the sublitoral zone. This appears to be its mode of growth also on the coasts of 

 England (Cp. Hakv. Phyc. Brit. tab. 18). But on the coasts of France and New Eng- 

 land its habitat is the same as at Finmarken, and this seems to be the usual case. 

 Kutzing says that it grows »in stagnis marinis et submarinis» (Cp. Spec. Alg. p. 403). 

 The present species is gregarious. I have collected specimens with zoospores on the 

 coast of Finmarken at the beginning of September. 



Geogr. Distrib. It is known from the Norwegian Polar Sea and Baffin Bay. The 

 most northerly point Avhere it is certainly known to grow, is Gjesvser about Lat. N. 71°. 



Localities: The Norwegian Polar Sea; Nordlanden rather common; Finmarken, lo- 

 cal and not abundant at Gjesvasr and Talvik. 



Baffin Bay: Greenland according to specimens in the herbarium of the Copenha- 

 gen Museum. 



Cladophora Crispata (Roth) Rabenh. 

 Fl. Bur. Alg. p. 333 et 336. Conferva crispata Roth. 



With regard to this species found in the White Sea by K. von Baer, the reader 

 is referred to Gobi, Algenfl. Weiss. Meer. p. 85. 



Gen. Rhizoclonium Kutz. 



Phyc. gener. p. 261. 



Rhizoclonium Rigidum Gobi. 



Algenfl. Weiss. Meer. p. 85. 

 Descr. Ehizoclonium rigidum Gobi, 1. c. p. S6. 

 EiDsice. Conferva fracta f. longissima subsimplex Aresch. Alg. Scaud. exsicc. N:o 273. 



Syn. Cladophora fracta Klekn, Nordl. Alg. p. 45. 



Habitat. This species grows in lagoons or depressions in the litoral zone, and is 

 at first attached, afterwards floating on the surface as loose masses of indefinite shape. 

 It is gregarious. I do not know anything with regard to its propagation. 



