thp: fuesh-water cyanophyceæ of iceland 273 



II. HORMOGONEÆ. 



1. OSCILLATORIACEÆ. 

 /. LYNGBYEÆ GOMONT. 



I. Oscillatoria Vaucher. 



Oscillatoria ppoboscidea Gom. var. Westii De-Toni. 



De-Toni Sylloge Alg. vol. V p. 1 52. 



O. prohoscidca var. West 1902 p. 245, figs. 28-30. 



N. Icel. Akureyri, in hot springs, temp. 35 °— 40 *^ ^Vt 1914 (3 sam- 

 ples); ibid., in hot spring "Ve 1903 (O. P.)! — W. Icel. Hveravellir, in hot 

 springs, temp. 24 ^—38 '^ C. (West 1902 p. 245). Stora Kroppar, stream 

 below laug, temp. 15° ^s 1914 (typica?). Reykholt, outlet from Skrifla, 

 temp. 25 ° ^/s 1914. — S. I cel. In stream from Great Geysir, mean temp. 

 about 40° C. (West 1. c). Reykjafos; in hot stream, temp. 35° ^^/s 1914; 

 ibid., in hot spring, temp. 32 ° '^/s 1914. Laugarvatn, outlet from laug, 

 temp. 36° ^Vs 1914. Reykjavik, Laugarne, temp. 35° ^/s 1914; ibid, temp. 

 40° -/lo 1896 (H. J.)! 



This variety is only known from Icelatid where it, to begin with, 

 was found by West in samples from Hveravellir and Geysir. Later I 

 have myself found it at the majority of the hot springs I have visited 

 (frequently in temp. of 32 °— 40 ° C). At Stora Kroppar only I found 

 in a sample from the stream below a "laug" some few trichomes of 

 same, but one might well imagine that these originated from the hot 

 spring. The variety I chiefly distinguished from the species by the greater 

 thickness of the trichomes. On the dried material faint constrictions 

 can be seen between the cells, but it is not by any means certain that 

 these could be seen on living specimens. It is not quite improbable 

 that var. Weslii in reality may possess so many distinctive features that 

 it could be placed as an individual species. This, however, I could not 

 do as I lacked the necessary material for comparison. 



O. proboscidett does not belong to the common species, but its 

 habitats are to be found all over the world especially in Eur., Afr., As., 

 Antarctic, Alaska. Therefore it is probable that it will prove to be an 

 Ubiquist. It has not been found in hot springs at other piaces than Iceland. 



Oscillatoria sancta Kiitz. 



Goraont, Monogr. II p. 209, pi. VI fig. 12. 



E. Icel. Vallanes ^-/s 1893 (H. J.)! — N. Icel. Skutustat)ir, pool in 

 which a spring flows out, temp. 7° ^V? 1914. Myvatn near Geitey- 

 jarstrond, washed ashore ^^/7 1914; ibid., scpieezed out of Sphagnum 

 on the shore ^Vt 1914. 



Area: All continents, Antarctic, Fr. Josephs Land, Greenland. 



Has been found under highly varying external conditions: in water 

 (stagnant and running), on earth and rocks. In Iceland I have only 

 found it in the neighbourhood of Myvatn in a cold spring and on the 

 lake-margin. 



