THE frp:sii-\vatkr cyanophyceæ of icelaxd 307 



III. Desmonema Berkele}^ et Thwailes. 



Desmonema Wrangelii (Ag.) Bom. et Flah. 



Bornet et Flahault, Bevision III p. 127. Wittr. et Nordst. Alg. exsicc, 

 nr. 675. Lemmermann 1910 p. 201, p. 198, fig. 3. 



E. Icel. Vestdalur at Seyc)i.sfj6r6ur, slightly damp rocky wall, for- 

 ming dark patches */? 1914. Ekkjufell, drlpping rocks -/'? 1914. 

 Area: Eur., As., Am., Austr., Færoes, Alaska. 



The habitat most favourable to tliis species is said to be cold moun- 

 tain streams (Lauterborn 1910 p. 493, Lemmermann 1. c). In Iceland 

 I found it in piaces on which it undoubtedh' will desiccate completely 

 during the summer. At the time when I visitcd the localities, water 

 was trickling down in abundance over the rocks from the melting snow. 



IV. Hydrocoryne Schwabe. 



Hydrocoryne spongiosa Schwabe. 



Bornet et Flahault, Revision III p. 128. Lemmermann 1910 p. 222, 

 p. 198, fig. 4. 



E. Icel. Vallanes ^^5 1893; two samples, one of them from "Siki". 

 (H. J.)! — W. Icel. Glammasta5avatn at Geitaberg, on stones at the 

 shore, temp. 15'^ Vs 1914. 



Area: Eur., South-Patagonia. 



This species occurs almost always attached to piants or other solid 

 objects in fresh water. Its distribution is apparently but little known; 

 presumably it has often been overlooked. 



IV. SIROSIPHONACEÆ. 



I. Hapalosiphon Någeli. 



Hapalosiphon laminosus (Cohn) Hansg. 



Bornet et Flahault, Revision III p. 56. 



Aiilosira thermulis West 1902 p. 244, figs. 1—10. 



Mastigocladiis laminosus West 1. c. figs. 11—16. 



Sphærozyga Japeti Liebm. 



S. thermanim Liebm. 1840 p. 338; Fl. dan., tab. 2399. 



N. Icel. Namuskar(^. in hot stream, water alkaline, temp. 35^ 

 ^^li 1914 f. anabænoides and f. phormidioides. Ibid.. at the source of 

 the hot spring, temp. 45*^ f. typica. Uxahver, on silicious sinter at the 

 hot spring ^-/y 1914 f. typica. Ibid., in outlet from spring, temp. 35'^— 

 540 22 j^ \^\i f. anabænoides. Reykhus, S. of Akureyri, hot spring, 

 temp. 48° V? 1914 f. anabænoides. Akureyri, hot spring (O. P.)! ^^6 

 1903 f. anabænoides. — N. W. Icel. Reykholar, margin of hot spring, 

 in the surface of the algal layer 20'^ ^/t 1915 (H. J.i! f. tyi)ica. Reykjanes, 

 hot spring (58*^') (Th. Th.)! t; typica. — W. Icel. Hvcravellir (55°— 61*^) 



