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Desmarestia ligulata (Lightf.) Lam. 



I have seen in the herbarium of the Botanical museum at Copenhagen 

 one specimen belonging to this species, on the label of which is written: „Fucus 

 ex Islandia". As neither the collector nor the tinding place is known it must 

 be regarded as a doubtful Icelandic plant, but as it occurs in the Færoes it 

 may also possibly be found in S. Iceland. 



Fam. Chordariaceæ. 



€astagnea virescens (Garm.) Thür., Rosenv. Deux. Mém. p. 58 ; Eudesme 

 virescens Ström f. Algveg. p. 47. 



This species occurs in rock-pools in the litoral region, and in the 

 upper sublitoral region down to a depth of 5 fathoms. It had unilocular 

 sporangia in June — September and plurilocular sporangia in August. The 

 frond attains a length of 30 cm. 



E. I c el. Fossårvi'k in Berufjöröur. 



N. I c el. Arnarnes in Eyjafjöröur. 



NW. I c el. Kolbeinsâ, Broddanes. 



SW. I c el. Stykkishölmur, Olafs vi'k, Einarslön. 



Leathesia difformis (L.) Aresch., Kjellm. Arct. Alg. p. 252. 



Grows in rock-pools in the litoral region near low-water mark. It is 

 only known from two places, in the one of which, Reykjavik, it occurred 

 gregariously on Ahnfeltia plicata, Gorallina and rocks. It had plurilocular 

 sporangia in June and August (in Reykjavik). Specimens from NW. Icel. 

 gathered in September were sterile. 



NW. Icel. Kolbeinsâ. 



SW. Icel. Reykjavik (G. 0., B. Sæmundsson !). 



Chordaria flagelliformis (Müll.) Ag., Strömf. Algveg. p. 47 ; Rosenv. 

 Grl.Havalg. p. 854. 



All the Icelandic specimens belong to the typical form. They are up 

 to 55 cm. long and occur in the litoral region attached to rocks or other 

 algæ; the species is also found in the upper sublitoral region down to a 

 depth of 5 fathoms. Fructiferous specimens are met with in June-October. 



Common everywhere on the coasts. 



Fam. Chordaceæ. 



Chorda tomentosa Lyngb., Hydrophytologia Dan. p. 74; Rosenv. Grl. 

 Havalg. p. 854. 



This species occurs in the lower part of the litoral region and in 

 the sublitoral region down to a depth of more than 10 fathoms. The 



