244 KJELLMAN, THE ALG OF THE ARCTIC SEA. 
one, while this has never been observed in the Tangle» (= LZ. stenophylla). I think no 
one is entitled to doubt that this statement of Ciusron is founded on complete re- 
searches continued through the whole year. Nevertheless it proceeds from J. E. Arn- 
SCHOUG'S investigations — according to oral communications kindly given — that the 
Scandinavian L. digitata changes its lamina periodically in the same manner as ZL. 
Clustoni and that at the fall of the lamina the limit between the young and the old 
one is quite as distinctly marked as in the last-named species. The same observation 
has been made by Fosuiz and set forth in his work Digit. Lam. p. 6. He mentions 
also that there are quite as distinct yearly rings to be seen in L. digitata as in L. 
Clustoni, which confirms my observations in respect to ZL. digitata f. complanata. Cp. 
Kyetum. Kariska hafvets Algv. tab. 1, fig. 14. Such rings, according to Lr Jomts, are 
not to be found in L. fleaicaulis, which I have taken to be identical with ZL. digitata 
var. stenophylla Harv. — For these reasons I am opinion that, even after L. Clustoni 
has been segregated from L. digitata, there still remains in the last-named old collective 
species not one but two species, the one perennial, annually throwing off its lamina 
regularly as L. Clustont and possessing in its stipe thickening-layers of the same kind 
as in this species, and the other possibly biennial, as Lr Joxis supposes, fast increasing 
in size, with a stipe that »ne présente pas d’anneaux concentriques» and a lamina that 
»se développe d’une maniére continue et indéfinie; et pour ce motif peut atteimdre de 
grandes dimensions». The former species is L. digitata of J. G. AGarpu and J. E. 
ArescnoueG, the latter is Z. digitata Epm., L. digitata var. stenophylla Harv., L. steno- 
phylla J. G. Ac. It possibly is the former of these species, L. digitata J. G. AG., 
Arescu., that Le Jonts refers to 1. c. p. 553, when he says: »Cependant on trouve 
quelquefois dans le Lam. flexicaulis un état de végétation qui le rapproche du Lam. 
Clustoni. Alors un certain arrét a lieu dans la croissance de la plante et un léger 
rétrécissement s'est manifesté dans une partie de la fronde.... c’est dans ce cas encore 
qu’on remarque dans le stipe du Lam. flexicaulis de traces d’anneaux colores...» In 
such a case L. flexicaulis Le Jou. would include not only L. stenophylla J. G. AG., but. 
also L. digitata J. G. Aa., Aruscn. 
It is another question whether this Z. stenophylla is really to be found within the 
Polar Sea. I have never myself seen any specimen taken here. My recording it among 
the arctic algw is founded only on Kuesy’s statement that he has collected it at Nord- 
landen. I had so much the less reason to doubt its occurrence here, because the species 
is apparently northern and moreover is stated by J. G. Acarpu to have been collected 
by himself at Throndhjem. Neverthless I am not quite sure whether Krsen has not 
mistaken also young individuals of L. digitata with cuneate base growing in rock-pools 
for L. digitata var. stenophylla. 1 have myself met with specimens at Nordlanden which 
resemble Harvey's figure of ZL. stenophylla in the form of the lamina, but are un- 
doubtedly young specimens of L. digitata. 
Habitat. It is said by Kienn to live at low-water mark as well as in rock-pools 
within the litoral zone. 
Geogr. Distrib. Reported from the Norwegian Polar Sea. 
Locality: Nordlanden: common and abundant according to KLEEN. 
