236 



Lat. cell. veget. = 22 jw; lat. sp. = 25 ^^. 



In collections from Traiigisvaag (Syd.); and Bosdalafos (Vaago). 



In Hydrophyt. pp. 174 — 5 Lyngbye nientions having met with 

 Zygnema bipiinctatiim and Z. pectinatiiin in the Færoes. Of the former 

 only one specimen is to be found in Lyngbye's Herbarinm in the 

 Botanical Museum, Copenhagen, and it is gathered »in rivulo ad 

 Thorshavn« and named by Lyngbye var. compactiim. The material 

 is sterile. The cells have very thick walls (crass. parietis = 1 u; 

 lat. fil. = 48 f(). They possess rather numerous rhizoids. This has 

 also been noticed by Lyngbye as he has labelled it as follows: ~ 

 »Fila fragilia, albida, omnino ad modum ejus exemplaris, quod ad 

 Græsmarken prope HoITmannsgave lectum, delineavi. Hoctamen 

 interduni parvos curvosque emittet ramulos, qui tamen sine dubio 

 sunt exemplaria copulata.« Rostrup (Fær. Fl. p. 89) thinks that il 

 resembles Z. criiciatiim and I am also inclined to think so. Wille 

 (1. c. pp. 29 — 30), on the other band, is of opinion that it agrees 

 with Z. stellimim; and he is so confident of the faet, that on the 

 faith of it, and on that of sonie sterile fdaments found in Mr. Pa- 

 tursson's collection, he does not hesilate to include it in his list. 

 I, for one, am of opinion that it is impossible to determine sterile 

 Zygnemaceæ with certainty, which is also pointed out by De Bary 

 (Conj. p. 78). 



The material of Lyngbye's Z. pectinatiim is also sterile and 

 therefore indeterminable; Wille thinks that it is identical with 

 Z. criiciatnm. 



219. Zygogonium ericetorum Kiitz. 



This species I have found in gatherings from Gliversrejn near 

 Thorshavn (Str.); Nolso; and Midvaag (Vaago). 



Lyngbye's Con fer va ericetorum (Hydrophyt. p. 140) is probably 

 identical with this species, but this cannot be proved for cerlain 

 as the material in Lyngbye's Herbarium in Copenhagen is sterile. 

 Wille (1. c. p. 30) also mentions having found this species. 



220. Spirogyra catenæformis (Hass.) Kiitz. 

 Petit, Spirog. p. 17, tab. HI, hg. 9—12. 

 Lat. cell. veget. — 23 fi, lat. sp. — 30 fj. 



— — fruct. — 36 /< ; long. sp. = 70 — 80 //. 

 F'rodebo near Trangisvaag (Syd.). 



221. S. affinis (Hass.) Petit. 

 Spirog. p. 18, fig. 13—14. 



