No. 2] REMARKS ON LITHOTHAMNION MURMANICUM. 5 



L. soriferum Kjell m. — L. tophiforme Ung. 



L. fornicatum Fosl. — L. vardoense Fosl. 



The same is partly the case also with L. glaciale Kjellm. 

 and L. intermedium Kjellm. 



Of the species mentioned, peculiarly the four first ones form 

 a group distinguished by mostly short and curved or flexuous 

 branches. Cp. pi. I and Norw. Lithoth. pi. 6—8 and pi. 21, fig. 

 1—6. In localities where -L. Ungeri s^nå L. soriferum are growing 

 gregariously, it is in part rather difficult to draw the line belween 

 the two species, but they are no doubt specifically distinct. Re- 

 sides, delicate forms of L. nodulosum are nearly connected with 

 L. 7iorvegicum, and L. tusterense bears partly a close resemblance 

 to certain forms of L. Granii. On the other hånd L. fornicatum 

 and L. vardoense are characterized by straight — or almost straight 

 — branches. Both L. soriferum and L. tophiforme are much 

 varying species, approaching partly to one group, partly to 

 the other. 



It is not clear from Mr. Elenkin's description whether L. 

 murmanicum bears short and curved branches, nor does it appear 

 with certainty from the plate, in which, by the bye, the specimens 

 seem to have been reproduced on a scale rather considerably 

 reduced, though I cannot find the reduction stated. However, in 

 fig. 1, p. 13, and particularly in fig. 1, p. 26, it is quite distinctly 

 seen that the branches are flexuous. Air. Elenkin states p. 25 

 that they are about 3 mm. thick. The branches of L. Ungeri 

 and o{ L.hreviaxe, according to my measures, are 1.5 — 2.5 mm., 

 and those of L. nodulosum and of L. tusterense are only 1 — 1.5 

 (1.8) mm. thick. This proportion may be somewhat more varying, 

 but at any rate it shows that L. murmanicum is frequently much 

 coarser than L. nodulosum. In L. vardoense the branches are 

 1.5 — 2 (2.5) mm. thick, but they are — as above mentioned — 

 straight or almost straight. There are certainly forms of i>. no- 

 dulosum with partly almost straight branches (f. congregata), but 

 this is never the case in L. Ungeri or L. hreviaxe. 



I, therefore, must consider it as a probability verging on the 

 certain that L. murmanicum belongs to L. hreviaxe. Cp. pi. 1. 



