THE FRESH-WATER CYANOPHYCEÆ OF ICELAND 317 



to see whether it contained much chloride of sodium, but this did not 

 seem to be the case. I therefore conclude that the alga originated from 

 pure fresh water. 



R. Biasoletliana, in Lemmermann's emendation, occurs in salt water 

 as well as in brackish and pure fresh water. It may also grow on 

 earth, on dripping rocks etc. 



The folio wing species of Cijanoplujceæ are recorded by Lauder 

 Lindsay (1861). In the cases when the species has not retained the 

 same name, I add the name according to the nomenclature of our days. 



Coccochloris Grevillei Hass. var. botryoides Hass. = Aphanocapsa Gre- 

 villei (Hass.) Rab. 



Nostoc comnmne Vauch. 



Nostoc verrncosiim Vauch. 



Nostoc Uchenoides Vauch. = Collema sp. 



Riviilaria alra Roth (is a marine species). 



Raphidia angiilosa Hass. =^ Riviilaria natans (Hedw.) Welw. 



Oscillatoria tennis Ag. 



Oscillatoria antnmnalis Ag. — Phormidinni aiitnmnale (Ag.) Gom. 



Microcoleus repens Harv. — Microcoleiis vaginatus (Vauch.) Gom. 



Of these species I have not found Aphanocapsa Grevillei (Hass.) Rab. 

 and Riviilaria natans (Hedw.) V^'^elw. in the Icelandic material which has 

 been at my disposal. 



The same species are recorded again by Lindsay in 1867 (p. 200). 



I wish to express my best thanks to the trustees of the Carlsberg 

 Fund for having defrayed the expenses of my journey to Iceland and 

 for a grant to the production of my work. 



