THE FRESH-WATER CYANOPHYCEÆ OF ICELAND 



287 



they were procumbent or not visible at all. In this sample the diameter 

 of the trichomes was still smaller, viz. 3.9—4.4 //; this being thus 

 considerably less than the minimum stated by Gomont (1. c.) , 



with regard to the diameter of the trichomes in this species; / ' 



but the rather solid sheaths and the length of the cells /// 



have, nevertheless, induced me to refer this form to S. mus- \ 



coram and not to S. miiralis the cells of which are sup- / ^ 



posed to be shorter than the length. (Fig. 7.) This sample is ' /' 



presumably the original specimen of Fl. dan. table 2517.2, J^^^ 

 Oscillaloria elcgans. On the label this name is distincth^ writ- 

 ten in Liebman's hånd, and the locality also agrees. How- 

 ever, several other samples from Iceland exist, collected by 

 Steenstrup (e. g. from Geisir), and on which Liebman has 

 written the same name. I have referred these samples to 

 Phormidium Coriiim as they, according to my investigations, 

 can be distinguished with certainty from the samples from 

 Laugarne at Reykjavik. Thus Liebman was evidently not able 

 to distinguish Symploca Miiscoriim from Phormidium Coriiim; 

 but, judging from the evidence to band, the probabilities are 

 that it happened to be a specimen of Symploca Miiscoriim 

 which was drawn for Flora danica under the name of Oscil- 

 latoria elegans. It must also be the same alga which Liebman 

 mentions 1840 p. 337 and 339. 



The species in question has previously been found at 

 hot springs; but it is undoubtedly but a chance guest here. (Ag.)Gom.var. 

 It has most frequently been found growing on and among (X1200). 

 mosses in moist piaces, but it also occurs on bare, moist FromLaugar- 

 earth as well as in water, even free-floating. It has not pre- "t^y^'i^^ w 

 viously been found in any arctic or antarctic region which steenstrup. 

 might suggest that it is not capable of withstanding extreme 

 cold and at the same explain its occurrence at the hot springs. 



Fig. 7. 

 Symploca 

 Miiscorum 



Symploca muralis Kiitz. 



Gomont, Monogr. II p. 112, pi. II, fig. 10. 



S. I c el. Laugarne (Reykjavik?), hot spring. (Stp.)! 

 Area: Eur., As., Afr., Am. 



This species is mainly living on moist earth, walls, trunks and the 

 like. Therefore it is under deviating conditions that it was collected by 

 Steenstrup in Iceland, viz. at a hot spring; the probabilities are, how- 

 ever, that it has grown on the earth at the side of the spring although 

 the label does not contain any information as to this. The sample was 

 originally determined by Jobs. Schmidt. 



Symploca thermalis (Kiitz.) Gom. 



Gomont, Monogr. II p. 114, pi. II, figs. 15—16. 



W. Icel. Stora-Kroppar, in small laug, temp. 33*^ ^/s 1914. 

 Area: Eur., As., Afr., Am. 



In the hot spring at the farm Stora-Kroppar in the Reykholts valley 

 this species grew^ together with Hapalosiphon laminosus. The diameter 



