564 A. HESSELBO 



8. Grunnavik near Jokulsfjordur. A deep layer of 

 peat, here and there intersected with ditches. The following mosses 

 were observed: Pohjtrkhum alpinum, P. Swartzii, Mnium hormim, 

 Pohlia mitans, P. ciiciiUata (both common), Bryum purpurascens, 

 Ceratodon purpureiis, Dicranella cerviculata, D. crispa, Lophozia qiiin- 

 qiiedentata and a few tufts of Tetraplodon bryoides. Psilopilum lævi- 

 gatiim was found only scantily and after a long search. 



4. Lundur in W. Iceland. On a damp peat-flat, the upper- 

 most layer of which was pared off, grew Dicranella Schreheri, 

 Aongstræmia longipes, Bryum lacustre, B. inclinatiim , B. æneiim, Di- 

 chodontiiim pelhicidiim , Philonotis fontana, Meesea trichoides and 

 Aneura pingnis. 



The Bryophyte Vegetation of Damp Sandy Soil. 



The damp sandy or gravelly ground along streams, inundated 

 only in the case of especially high water-levels , is often covered 

 with a moss carpet of a very mixed composition. Here liverworts 

 play an especially important part, and very frequently pure liver- 

 wort associations are met with, or other associations in which the 

 liverworts are almost dominant. They are almost everywhere the 

 same species which are the most abundant constituents of the moss 

 carpet. The following Hepaticæ are the most frequent: Scapania 

 sabalpina, Alicularia scalaris, A. geoscypha, Lophozia quinquedentata 

 Cephalozia bicnspidata var. Lammersiana, Anthelia julacea, A. Ju- 

 ratzkana, and, especially in NW. Iceland, Harpanthns Flotowianus. 

 Intermixed with the above occur a very great number of species 

 of which the most frequent are Pellia Neesiana, Aneura pinguis, 

 Haplozid atrovirens, Cephalozia pleniceps, Dicranella crispa, Dichodon- 

 tium pellucidum , Aongstræmia longipes, Didymodon rubellus, Disti- 

 chium montanum, Pohlia commutata , P. gracilis, Bryum pallens, B. 

 inclinatum, B. af fine, Philonotis tomentella , P. fontana, Pogonatum 

 urnigerum and Timmia austriaca. A few less common species, 

 such as Blasia pusilla, Eucalyx subellipticus and Distichium inclina- 

 tum, also belong to this community. Somelimes a moss-covering 

 of another composition is also met with, Bhacomitrium canescens 

 often forms extensive mats on wet sandy ground. In North Ice- 

 land Timmia austriaca and Philonotis tomentella are found plenti- 

 fully in many piaces on the damp ground above the Philonotis- 

 belt, as a rule abundantly mixed with other species. Dicranella 

 crispa is also very often found in great quantities on damp sandy 



