THE FRESH-WATER CYANOPHYCEÆ OF ICELAND 



269 



Kutz. Alg. III nr. 29 



Wittr. et Nordst. Alg. exsicc. 

 nr. 695 



— — — nr. 794 



— — — • nr. 1595 a 



— — — nr. 1596 a 



— — — nr. 1596 b 



— — — nr. 1597 a 



— — — nr. 1597 b 

 Phycotheca Bor.-Am nr. 251 



— — nr. 1302 



Hauck et Richter Phj'c. uni- 

 vers, nr. 91 



— — — — nr. 193 

 Rab. Alg. Eur. nr. 1572 



— Alg. Sachsens nr. 3 . . . 



Specimens from Iceland . . . 



O) 



C 

 es 



C 



o 



o 

 u 



s 



o 



bu 



4.4- 

 4.6- 

 4.8- 

 4.8- 

 4.6- 

 4.4- 

 4.6- 

 4.8- 

 4.0- 

 3.3- 



-5.5 

 -6.2 

 -6.4 

 -6.2 

 -5.5 

 -5.5 

 -6.1 

 -5.7 

 -5.5 

 -4.4 



4.6—6.2 



4.2- 

 4.4- 



-4.4 

 -6.2 



4.8-5.5 



3.3—6.2 



roundish 



somewhat 

 lobed 



lobed 



irreg. 

 form 



roundish 



somewhat 



lobed 

 somewhat 



lobed 

 somewhat 



lobed 

 somewhat 



lobed 



lobed 



roundish 

 lobed 



somewhat 

 lobed 



roundish 



/(326) 

 I 333 

 (332 

 \ 326 

 ((308 

 (326 

 ((309)? 

 \ 331 

 ((326) 

 \ 352 

 (308 

 i 326 

 (333 

 ( 326 

 ((312) 

 1326 



+ 



+ 

 + ? 



+ 



+ 



stagn. 



prås. 



stagn. 



prås. 



stagn. 



prås. 



stagn. 



stagn. 



Moo- 

 reana 



stagn. 

 stagn. 

 stagn. 

 stagn. 

 stagn. 

 stagn. 

 prås. 

 stagn. 



prås. 



stagn. 

 prås. Spec. orig. ! ! 



Aphanothece 

 stagn. coerulescens. 

 A. Br. 



The difference in colour is, liowever, not so wide as might be inia- 

 gined according to the Codex-numbers stated. There is, for instance, 

 in faet but a slight difference between nr. 308 and 326, and in the va- 

 rious specimens from the same sample several colour-tones are repre- 

 sented, e. g. in Phycotheca univers, nr. 91 \ve find the following: 330, 258, 

 280 of which nr. 330 probably represents the colour of specimens in 

 a young stage, the more brownish, i. e. 280 and 258, the older stages 

 where the colour is more or less faded. 



Consequently the exsiccata cannot be divided into two types with 

 different colour-tones. If anything, an even gradation of colour-tones 

 from the brown (258) to the bluish (351) is found. Between the 



