200 



perfectly agree with the Greenland form. Further up in the streamlets where the water 

 is but little brackish, it assumes a different aspect, becoming dvvarfed, 2 — 3 inches high, 

 with only the lower segments elongated, the upper ones being, on the contrary, very 

 short and densely fasciculate; almost every segment of the last order bears a spherical 

 receptacle, 2— .3 mm. in diameter. 



Hahitat. This species is generally litorai, at least in the Norwegian Polar Sea 

 and the immediatelj' adjacent parts of the Arctic Sea. The form vadorum, however, is 

 sublitoral, preferring sheltered localities. The others are to be found at exposed as 

 well as sheltered places of the coast. I have already mentioned that I have found f. 

 spliwrocarpa at the mouths of streamlets on the coast of Finmarken. Some of the forms 

 grow in society, in large masses, contributing strongly to the character of the vegetation 

 for considerable stretches. This is especially the case with f. typica and f. tiirgida on 

 the north coast of Norway. All the forms mentioned have been taken in the Norwegian 

 Polar Sea with receptacles in summer, June — August. I have seen specimens from 

 Greenland with receptacles, collected in the month of July. Gobi reports f. angustifrons 

 with receptacles from the »Vhite Sea, probably taken in summer. 



Geogr- Distrib. In consequence of the present species having been confounded 

 with F. evanescens, it is impossible to decide its area of distribution by means of the 

 accessible literature. I believe that it does not grow in any other parts of the Arctic 

 Sea than the Norwegian Polar Sea, the western Murman Sea, the White Sea, and Baffin 

 Bay, and that all F. vesiculosus which has been reported from other arctic regions is 

 either F. evanescens or possibly some individuals of F. vesiculosus which have drifted 

 there from more southern parts. Such is probably the case with those fragments of 

 F. vesiculosus which were stated to J. G. Agaedh to have been collected at Spitzbergen. 

 Cp. J. G. Ag. Grönl. Lam. and Fuc. p. 30. The present species has no doubt its maxi- 

 mum of frequency in the Norwegian Polar Sea. Already in the White Sea F. vesicu- 

 losus is less plentiful than F. evanescens; see GoBi, 1. c. p. 54. The extension of the 

 species northwards is uncertain. 



Localities: The Norwegian Polar Sea: Nordlanden, f. vadorum common, f. typica 

 common, f. angustifrons scarce, f. sphcerocarpa scarce; Tromsö amt: f. typica common 

 and abundant at Tromsö, Renö, and Carlsö; Finmarken, f. typica common and abundant 

 at Maasö, Gjesvajr, the soiith coast of Magerö, öxfjord, and Talvik; f. angustifrons local 

 and scarce at Gjesvser; f. turgida local, bnt abundant, at Maasö and Gjesva^r; f. sjyhcero- 

 carpa scanty at Gjesva^r. 



The Murman Sea: the coast of Russian Lapland (f. sphcerocarpa). 



The White Sea: f. angustifrons and f. spha'rocarp>a less abundant. 



Baffin Bay: f. sphairocarpa with certainty on the west coast of Greenland, as at 

 Julianeshaab, Sukkertoppen, Godhavn, Rittenbenk, probably also at Egedesrainde and 

 in Ciimberland Sound. Other reported localities dubious. 



The hybrid form F. serratus + vesindosns has been found l)y Kleen at Nordlanden 

 in the Norweirian Polar Sea. 



