The calcareous alga in question has been described by Mr. 
A. Elenkin from specimens collected on the Murman coast.!) 
Mr. Elenkin states that the alga is most nearly approaching to 
- Lithothamnion nodulosum Fosl., and refers to specimens from 
arctic Norway coilected by Dr. Palibin and determined by me. 
In fact I have determined no such calcareous alga from the area 
quoted, but certainly from the southern part of the west coast of 
Norway (the neigbourhood of Bergen). This form corresponds, 
however, in all essentials with L. nodulosum whose typical form 
occurs in the Trondhjemfjord. Hoping to obtain by way of ex- 
change a specimen of L. murmanieum so as to be able to com- 
pare it directly with species nearly connected, I did not go more 
accurately over the description of the alga. But I thought it likely 
to be identical with Lithoth. vardöense, because forms of this spe- 
cies are in habit partly approaching to L. nodulosum in almost 
the same proportion as L. nodulosum and L. formicatum are 
sometimes approaching to one another. As typically developed, 
however, they are much diverging. 
In another paper?) Mr. Elenkin tries to prove that L. vardö- 
ense and L. murmamicum are identical, and that the latter name 
has a priority of claim. I will not here enter on the question of 
priority. But after going more accurately over the description, I 
make out — quite the contrary — that the two species mentioned 
1) Bull. Jard. Imp. Bot. St. Petersb. Vol. V. No. 5 & 6. 1905. (Russian with 
a summary in German). 
2) Trav. Soc. Imp. des Naturalistes de St. Peiersb. Vol. XXXVII. Livr. I, 
(Russian with åa Summary in German). 
