520 A. HESSELBO 



indistincta, niargine leniter dentato. S eta 8 mm. longa, c. 14 mm. crassa, 

 purpurea , in dimidia parte superiori rugosa, inferne glabra. Capsula 

 fusca, obliqua. longe ovata, operculata 1.7 mm. longa, 0.5 mm. crassa, 

 deoperculata sub orilicio contracta. Operculum conicum 0.6 mm. altiim. 

 Dentes peristomii 0.46 mm. longi. 0.067 mm. lati, pallide lutei, 

 apicibus hyalinis, basi aurantiaci et leniter transverse striati. Sporæ 

 0.021— 0.024 mm., papillulosæ. 



S. Iceland: Flokastadagil, on stenes at the margin of the river. The 

 capsules were empty in the middle of July. 



249. Brachythecium populeum (Hedw.) Br. eur. 

 Hypnum populeum Hedw. 



S. Iceland: Vik (H.J.)!, fr.; Drangshlid!, fr. 



Grew in both the above localities on rather dry tuff rocks. 



25{). Brachythecium velutinum (L.), Br. eur. 



S. Iceland: Thingvellir (Grl.;!- Vik (H.J.)!; Holt!, in a cave at an 

 attitude of about 300 metres, fr. 



Near Thingvellir it grew in a lava-cleft, associated with Blepharo- 

 stoma trichophylhim, Plagiochila asplenioides and Plagiothecium silvaticum. 



251. Brachythecium glaciale Br. eur. 

 Hypiuim glaciale C. Hartm. 



N. Iceland: Akureyri!, at an altitude of 770 metres. NW. Iceland: 

 Sugandafjordur!, at an altitude of 450 metres. W. Iceland: Dalasysla, 

 Melår, on a cliff inhabited by sea-fowl (H.J.)!. 



On damp gravelly flåts. Near Sugandafjordur it grew abundantly, 

 intermixed with Hypnum stramineum, Miiiubryum albicans and Philonotis 

 fonlaiia, in cushions 3—4 crii. deep, on ground saturated by melting 

 snow, and on stones. The piants were about 5 cm. long and irregularly 

 branched with unequally long — mostly short — branches. The leaves 

 were erectly spreading, nol secund, and very longly decurrent with 

 numerous quadrate, thin-walled cells at the basal angles of the leaves. 



252. Brachythecium reflexum (Starcke) Br. eur. 



Commonly distributed. 



This species has its main distribution in gravelly spots on the 

 rocky flat, especially on slopes and dry snowless patches on the moun- 

 tain heights. It is especially abundant in NW. Iceland, where it is 

 everywhere the most frequently occurring species on stony slopes. Here 

 it is usually found associated with Hypnum uncinatum, Lescuræa spp., 

 Lophozia lycopodioides, L. Flærckei, etc, and is met with as high as about 

 500 metres aboVe .sea-level. In Esja, in SW. Iceland, it was common 

 from about 200 metres upwards. In the low land it is rarer and appears 



