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substrata. Collected with cystocarps in May — Sept., with tetraspores in 

 April — June. 



Low specimens. 1.6 — 2.5 cm. high, with proportionally broad fronds, 

 the f. typica Kjellm., and higher specimens, 5 cm. high, with proportially 

 narrow fronds, the f. angustata Lyngb., seem to be equally common. 



Probably common round the Icelandic coasts. 



E. I c el. common. 



N. I c el. Asmundarstaöir (St.); Eyjafjöröur. 

 NW. I cel. and SW. lcel. common. 

 S. I c el. Vestmannaeyjar. 



Rhodophyllis dichotoma (Lepech.) Gobi., Strömf. Algveg. p. 26. 



Sublitoral in a depht of 2 — 20 (usually 5 — 10) fathoms. Collected 

 with cystocarps and tetraspores in May and July. 



All the Icelandic specimens belong to the f. typica, and I have only 

 met with few specimens that somewhat resembled the f. fusca Lyngb. 



Probably common round the Icelandic coasts. 



E. lcel. common. 



N. I cel. Asmundarstaöir (St.); Giimsey (O. D.) ; Eyjafjöröur. 

 NW. lcel. and SW. lcel. common. 



Fam. Rhodymeniaceæ. 



Rhodymenia pa I ma ta (L.) Grev., Kjellm. The Algæ of the Arctic Sea 

 p. 147. Strömf. Algveg. p. 27. R. pertusa Strömf. 1. c. p. 28. 



It grows in the lower part of the litoral zone, especially in rock- 

 pools, and in the upper part of the sublitoral region. Very common and 

 abundant round the Icelandic coasts. Collected with tetraspores in Febr., 

 April— May, July and October, with antheridia in January. 



F. typica Kjellm. 1. c. (Fig. Turn. Hist. Fuc. T. 115, f. a.) To the f. 

 typica of this many-shaped species, I refer all the Icelandic specimens, 

 which have „the majority of the secondary axes formed by repeatedly 

 subdichotomous branching". So taken the f. typica is a various forma 

 and connected with the f. proliféra by intermediate forms. It has 

 a height of 2 — 41 cm. and a breadth of 4 — 10 cm. The length and the 

 breadth of the divisions are very different. When the divisions are many 

 and become very narrow, the plant superficially resembles the 

 f. sarniensis, but differs from it by the broad, cuneate base. The length 

 of the divisions is varying from c. 1 /s to 4 /ö of the length of the frond. 

 Sometimes there occur specimens, the divisions of which are few, very 

 short and proportionally broad. The frond of these specimens is usually of a 



