THK frp:sh-wateh cyanophyceæ of iceland 



311 



N. Icel. Pond near Grimstaftir (Myvatn), on parts of ol(i piants 

 2^7 1914. - N. W. Icel. Botn in Geirl)j6fsfjor6iir (lake), temp. 10'^ ^Vv 

 1915 (H. J.)! 



The form foiind in these two samples bears an extremely close 

 resemblance to Fischera muscicola Thur. (Bornet et Thuret: Notes algo- 

 logiques p. 155, pi. 36) 

 { = Fischerella m. Gom.), 

 but is especiall}^ di- 

 stinguished from it by 

 its smaller dimensions 

 and shorter hormogo- 

 nes. The bearings of 

 chlor-zinc-iodine on the 

 sheath of F. muscicola 

 are up to Ihc present 

 unknown. On the other 

 hånd Gomont (1902 p. 

 299, pi. I) States with 

 regard to Fischerclla 

 major that its vaginæ 



do not assume a bluish tint with this reagent. By an examination of 

 the authcntic sample: Kryptogamae exsiccatae nr. 333, I have convinced 

 myself of the correctness of this statement. The habitat of the new 

 variety is also different to that of F. muscicola in that it grows on earth 

 whereas the other is found in water. 



Fig. 16. Fischerella muscicola (Thur.) Gom. var. 

 minor n. var. (X600). 



III. Stigonema Agardh. 



Stigonema ocellatum Thur. 



Bornet et Flahault, Revision III p. 69. 



N. W. Icel. Arnarfjor^ur, Hariot (1893 p. 316), Belloc (1894 p. 6). 

 Area: All continents, Lappland, Færoes, Alaska, Greenland. 



This species, which I have not seen in Iceland myself, is often 

 recorded as characteristic of sphagnum-moors, the water of which is 

 poor in mineral (Allorge 1921 p. 621). 



Stigonema panniforme (Ag.) Born. et Flab. 



Bornet et Flahault, Revision III p. 71. Hieronymus 1895 p. 164. 



S. tomentosum ibidem. p. 166. 



Sirosiphon compactus Rabenhorst Algen nr. 694. 



W. Icel. Kleppjårnsreykir, almost dry crusts Vs 1914 (2 samples). 

 Deildartungahver, not moistened by the water, ^/s 1914. — S. Icel. 

 Almannagja, on rocks over which water frequently was dripping ^V« 1914. 



Area: All continents. Færoes, Novaya Zemlyal 



Bornet et Flahault incorporate S. tomentosum with S. panniforme. 

 Hieronymus (1895), on the other band, attempts to separate S. tomen- 

 tosum from S. panniforme; but the position of the heterocysts is the 

 only important dillercnce which he is able to state, in that these in S. 



