4!) 



of these stations represent in a K^-neral way \hv sfHitliwestern 

 part of tlie island, but are at very considerable distances from 

 one another. One rather wonders that it has not been collected 

 there before. The related D.Julvellum has long been known from 

 Iceland, was indeed collected there by Morch before 1825, if the 

 Dicranum Moerkianum of Hornschuch* is correctly referred to 

 this species. t I also found what I take to be D. fulvellum in 

 the Almannagjd, but not growing with the other species. t The 

 two seemed to hold their characters entirely well in tlie places 

 where each was growing. They were fruiting abunrlantly, as 

 was D. Anderssonii also in the other two stations. My specimens 

 were all found growing upon post-glacial basaltic lava. 



Pleuridium alternijolium Brid. This plant was found in a 

 single spot growing on thin soil formed on the lava-field about 

 Hafnarfjordhur (July 23). Its case is quite the opposite of that 

 of the preceding Arctic plant, as this is so far as I know decidedly 

 its northernmost station, in fact the most northerly for any 

 species of Pleuridium. It was a surprise to find it so near the 

 Arctic Circle and I doubt that it will prove to be at all generally 

 distributed in Iceland. The impression most strongly made 

 upon me by my observations upon the Icelandic moss-flora w^as 

 that one has to do here not with a relict-flora, as in the familiar 

 case of our glacial relicts and perhaps also in the case of the so- 

 called "Atlantic species" on parts of the west coasts of Ireland, 

 Scotland, Norway and in the Faroes, but that it was rather 

 clearly a question of an immigrant flora, species of which had been 

 able to establish themselves there within relatively recent times. 

 The flora is on the whole a rich one, interesting no less in the 

 species lacking than in those actually found, and many questions 

 of distribution in their relation to wind and ocean-currents, 

 pre- and post-glacial lavas of different chemical constituency, etc., 

 represent interesting problems for investigation. 

 Ithaca, N. Y. 



* Flora. VIII, 78f. 1825. 



t The plate 2002 in Flora Danica, of which Mr. R. S. Williams has kindly 

 made me a tracing, is not identifiable as D. fulvellum; cf . Lindberg's note on this 

 plate in his Revisio critica iconum. 1871. 



J Gronlund also speaks of finding D. fulvellum in this place (Tidsskrift f. popu- 

 laere Fremstillinger af Natiirvidenskaben, 5 R., IV, 345. 1877). 



