THE BRYOPHYTA OF ICELAND 



507 



flexuoso-linearibus, apicalibus brevloribus, angulorum multo majoribus, 

 rectangulis. Folia ratiiuloriim angustiora. Flores et fructus ignoti."' 



This species, which was first found by Feddersen in tlie Helga 

 in S. Iceland, grew very abundantly on stones in the Rcykirdalsa in SW. 

 Iceland. This river lias copious intlux from the liot springs, so that, in 

 the first days of June, the temperature of the water was about 12°, 

 wliicli was essentially higher than in the majority of the otlier rivers 

 where the temperature was, as a rule, only about 4°— 6°. 



Fig. 12. Fontinnlis longi folia C. Jens. (Reykir; somewhat reduced). 



Fontinalis longifolia agrees most closely witli F. hypnoides W. Hartm. 

 Tlie plant from the Reykirdalsa is rather robust, as much as 25 cm. 

 long. very strongly and irregularlj' branched, with rhizoid-cushions around 

 all the points whence the branches issue, and with plane or somewhat 

 concave, longly tapering, very soft leaves, which only exceptionalh' are 

 folded along the median line. The cT plant is more slender than is 

 the 5 plant, with very numerous, narrowly ovate (^ flowers, which often 

 occur in clusters of 2 — 4 on the main axis and branches and contain 

 each 2—4 antheridia. The fruit, which in the beginning of June was 

 developed to almost fuU size, but was as yet quite green, so that the 

 peristome and spores could not be investigated, was found scantily on 

 the lowermost part of the slem. As in F. hypnoides the capsule was 

 half-exserted. 



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