46 



entangled. These fragments doubtlessly give rise to new 

 plants. On the whole the upper part of the frond of these 

 specimens is frangible and consists of many loosely interwoven 

 fragments between the main branches. On account of the loose 

 condition of the frond the fragments probably have changed 

 their position in proportion to the direction of the light, and 

 thus branches have become rhizoids and rhizoids branches. 



Specimens collected by Rosenvinge at Godthaab in a 

 depth of 5 fathoms, entangled between Desmarestia aculeata are 

 analogous to the f. debilis of A. hystrix. These specimens 

 have certainly been removed from the coasts by the current, 

 and afterwards thrown down to the bottom of the sea and 

 entangled between the Desmarestia. 



The specimens determined by Rosenvinge as Cladophora 

 arcta f. pulvinata (1. c.) are rather young, gregariously growing 

 plants of A. incurva. 



The species is littoral, it has only seldom been collected 

 at low-water mark and occasionally in the upper part of the 

 sublittoral region. It was collected in February — March and 

 May — August, with sporangia in June — August. 



The species seems to be common in West Greenland. 



Gr. occ: Umanak (Sören Hansen) ; Atanikerdluk, Ujaragsugsak 

 (N. H.); Godhavn (L. К. R.); Orpigsuit near Ghristianshaab (N. H.); 

 Sukkertoppen, Ny Hernhut (L.K.R.); Godthaab (Vahl, L. К. R.) ; Island 

 near Frederikshaabs Glacier, Frederikshaab, Smallesund (L. K. R.) ; 

 Neriak (N. H.) ; Ivigtut (L. K. R.) ; Sermilik Fjord (A. Jessen) ; Ata- 

 neritsok (Igaliko) (L. K. R.) ; Kakortok (Vahl); Kagsimiut, Juliane- 

 haab (L. K. R.) ; Sardlok, Umanartut, the northern side of Sermersok 

 (A. Jessen) ; Tasermiut prope Korsoak, Nanortalik (Vahl). 



Gr. or.: Ikerasak, Angmagsivik, Smalsund, Nualik. 



Geogr. distribution: Iceland, The Færoes, Norway. 



84. A. hystrix (Strömf.), Jonsson Icel. Alg. p. 368; Spongo- 

 morpha hystrix Strömfeit, Om algvegetationen vid Islands Ruster 



