KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND. 20. N:0 5. 237 



f. reniformis nob. 



f. lamina reniforrai, in laciiiias niimerosas usque ad basira digitato-lissa; lacunis muciferis stipitis nurae- 

 rosissimis in orbem regularem infra stratum corticale dispositis. 



«. longipes nob. 



f. stipite longiore usque 1 — 2 pedali, infra apicem complanato; laciniis laminje iiumerosis, sat latis. 

 Porraa a J. G. Agardhio descripta. 



(i. brevipes nob. 



f. stipite brevi, 2 — 6 pollicari; laciniis nuraerosissimis, augustis. 

 f. oblonga nob. 



f. lamina late oblonga, basi ssepe obliqua, Integra vel in lacinias latas, pauciores plus minus profunde fissa. 



«. compressa nob. 



f. stipite longiore usque tripedali, superne compresso, ssepe infra apicem valde complanato; lacuiiis mu- 

 ciferis stipitis irregulariter infra stratum corticale dispositis, paucioribus, magnis. 



/?. subteres nob. 



f. stipite breviore, subterete; lacunis stipitis minoribus, numerosis infra stratum corticale in orbem fere 

 regularem dispositis. 



Syn. Laminaria digitata f. latifolia Kjellm. Spetsb. Thall. 2, p. 26. 

 » )> forma Kjellm. 1. c. p. 26 — 27. 



» » f. typica (vera) Kjellm. Algenv. Murm. Meer. p. 38 et Kariska hafvets algv 



p. 25; ex parte '). 

 » » Kjellm. Vinteralgv. p. 64; ex parte. 



Remark on the species. In the collections of arctic algse that I have had the 

 opportunity of examining, there is to be found a Laminaria of the digitata group taken 

 in different parts of the Arctic Sea, which I have formerly confounded with L. flexicaulis 

 Le Jol. and recorded under the name of L. digitata. J. G. Agaedh has separated it 

 from L. digitata and described it as L. nigripes. By a more anatomical investigation 

 of a greater number of Laminarice from different regions I have arrived lately at 

 the conclusion that the structure of the lamina and the presence or absence of muci- 

 ferous lacunas in the various parts of the frond ought to be accounted more important 

 in distinguishing the species of this group of algaa, than I supposed formerly, relying 

 on the authority of J. G. Agardh. Consequently I must acknowledge L. nigripes 

 as a well differentiated species. It resembles closely L. digitata {L. flexicaidis Le 

 Jol.) in habit and possesses a series of forms similar with this, but in structure it 

 accords more nearly with L. Clustoni Le Jol. As in this species, there are muci- 

 ferous lacunar in the stipe, the middle layer of the lamina is very dense, sharply de- 

 fined from the intermediate layer and the latter layer composed of large cells with 

 thin walls. By these marks it is plainly distinguished from L. digitata {L. flexicaulis 

 Le Jol.). On the other side it differs decidedly from L. Clustoni by no cork layer 



') J. G. Agardh supposes that the Laminaria from the west coast of Greenland mentioned by Buown in Fl. 

 Disc, under the name of L. digitata is to be referred to the present species or to L. atrofulva. Cp. J. G. 

 Ag. Gronl. Lam. och Fuc. p. 18. 



