No. 2] REMARKS ON LITHOTHAMNION MURMANICUM. 5 
L. soriferum Kjellm. — L. tophiforme Ung. 
L. formicatum Fosl. — L. vardöense Fosl. 
The same is partly the case also with L. glaciale Kjellm. 
and L. mtermedium Kjellm. 
Of the species mentioned, peculiarly the four first ones form 
a group distinguished by mostly short and curved or flexuous 
branches. Cp. pl. I and Norw. Lithoth. pl. 6—8 and pl. 21, fig. 
1—6. In localities where L. Ungeri and L. soriferum are growing 
gregariously, it is in part rather difficult to draw the line between 
the two species, but they are no doubt specifically distinct. Be- 
sides, delicate forms of L. nodulosum are nearly connected with 
L. norvegicum, and L. tusterense bears partly a close resemblance 
"to certain forms of L. Granti. On the other hand L. fornicatum 
and L. vardöense 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. 
murmanieum 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 åa 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. Mr. Elenkin states p. 25 
that they are about 3 mm. thick. The branches of L. Ungeri 
and of L. breviaxe, 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. vardöense 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 L. no- 
dulosum with partly almost straight branches (f. congregata), but 
this is never the case in L. Ungeri or L. breviaxe. 
I, therefore, must consider it as a probability verging on the 
certain that L. murmanicum belongs to L. breviaxe. Cp. på. I. 
