KONGL. SV. VET AKAUEMIENS HAN1)I.INGAB. BAND. 20. N:0 5. 239 



with zoosporangia 9 and 16 January (richly), 2, 8, 14 February and 5 March. Having 

 called this alga by the name of L. digitata in ray notes, I am not sure as to what 

 species the plant which was then furnished with zoospores did really belong, but I 

 suppose it was L. nigripes of which I possess in my collections several specimens taken 

 in Musselbay, all of them appertaining to f. ohlonga. It is thus possible that the deve- 

 lopment of zoospores takes place at different seasons in the different forms on the coast 

 of Spitzbergen, during spring and the earlier part of summer in f. reniformis, during 

 autumn and winter in f. oblonga. From the north coast of Tshutsh-land I have one 

 specimen of f. reniformis taken in May, which is richly provided with zoosporangia, and 

 from the west coast of Novaya Zemlya one specimen of f. ohlonga taken in July with 

 mature zoosporangia. 



Geogr. Distrib. This species is probably circumpolar within the Arctic Sea proper. 

 I have found it most abundant and luxuriant on the north coast of Spitzbergen. The 

 most northern point where it has been taken is Treurenberg Bay on the north coast 

 of Spitzbergen Lat. N. 79° 56'. 



Localities: The Greenland Sea: the west and north coasts of Spitzbergen in Smee- 

 renberg Bay, Fairhaven, Musselbay, and Treurenberg Bay (f. reniformis and f. oblonga). 



The Murman Sea: the west coast of Novaya Zemlya at Karmakulbay (f. reiii- 

 formis). 



The Kara Sea: Uddebay (f. reniformis). 



The Siberian Sea: the north coast of Tshutshland — some miles east of the win- 

 tering-station of the Vega (f. reniformis). 



Baffin Bay: the west coast of Greenland according to J. G. Ag. Gronl. Lam. och 

 Fuc. p. 18 sub L. atrofulva. 



Laminaria Clustoni Edm. 



Fl. Shetl. p. 54, sec. Le Jol. Exam p. 577. 



f. typica FosLiE. 



Laminaria digitata f. typica Foslie, Digitata-Lam. p. 15. 

 Deser. Laminaria Clustoni Le Jol. 1. c. 

 Fig. Laminaria digitata Harv. Phyc. Brit. t. 223. 



f. longifolia Foslie. 

 1. c. p. 19. 

 Descr. Laminaria digitata f. longifolia Foslie. 1. c. 



Syn. Pucus digitatus Wg. F1. Lapp. p. 492; ex parte. 



» hyperboreus Gdnn. F1. Norv. 1, p. 34, t. 3; saltern ex parte sec. Foslie, 1. c. p. 11. 

 Laminaria digitata Foslie, 1. c. p. 14. 



Habitat. I have never myself met with this species in the Polar Sea. According 

 to Foslie who has devoted himself to the elucidating of the Scandinavian Laminaria^ 

 of the digitata group, it grows exceptionally within the literal zone, usually gregarious 

 within the sublitoral zone at places exposed to the sea or in such more sheltered 



