235 



218. S. Pseudosebaldi Wille. Plate VII, (ig. 17. 



Norges Ferskvaiidsalg. p. 45, tab. 2, lig. 80. 



Formå færoensis præcipue dilTert radiis Icnnioribus el longiori- 

 biis; bal)itu eelhilæ graciliore. 



Long. — 50 /<; lal. = 67 fi; lal. istlim. = 18 jM. 



Found in a colleclion of algæ from Svartaloselv near Thorshavn iSlr.). 



The Færoese form differs from the above-named as it seems 

 ralher schemalic figure given by Wille mainly in ils more slender 

 build; it resembles very much Wolle's figures 8 and 9 in Desm. 

 U.S. tab. 46. 



214. S. furcigerum Bréb. 

 Skopen (San do). 



215. S. brachiatum Ralfs. 

 Klakken by Klaksvig (Bor do). 



216. S. inconspicuum Nordst. 

 Norges Desm. p. 26, tab. 1, fig. 11. 



Of this species a few specimens were found which are distin- 

 guished by their forming short fdamenls; these showed a regular 

 twist as is commonly seen in the fdamentous Desmids. 



Long. = 20 jm; lal. cum brachiis = 24; lal. isthm. = 9,5 |W. 



Svartafoselv near Thorshavn (Str.). 



Order IX. ZYGNEMACEÆ. 



217. Zygnema stellinum (Vauch.) Ag. 



The form observed corresponded hest with the variety Vaiicherii 

 (Ag.) Kirchn.; it was on the whole smaller than the form mentioned 

 by me in »Ferskvandsalg. fra Østgrønl.« p. 83, lig. 1. The spores 

 are at first brownish and Iben blackish-blue (according to malerials 

 preserved in spirit). The scrobiculations in the spore-membrane 

 were tirst visible when the spores were crushed. This form has 

 furlher confirmed me in my opinion (cfr. 1. c. p. 33) that Z. pelio- 

 sporiim Wittr. can hardly be anything more than a variety belonging 

 to this species. 



Lal. cell. veget. — 21 fi; lat. sp. = 30 ;". 



In a gathering from Frodebo near Tværaa (Syd.). 



218. Z. lejospermum De Bary. 



I have only found this species with immature spores, so I am 

 nol quile sure as to the correctness of the determination. 



