564 A. HESSELBO 



3. Grunnavik near Jokulsfjordur. A deep layer of 

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

 were observed: Polytrichum alpinum, P. Swartzii, Mnium hornum, 

 Pohlia nutans, P. cuciillata (both common), Bryum purpurascens, 

 Ceratodon purpureus, Dicranella cerviculata, D. crispa, Lophozia quin- 

 qaedentata and a few tufts of Tetraplodon bryoides. Psilopilum Icevi- 

 gatum 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 Schreberi, 

 Aongstroemia longipes, Bryum lacustre, B. inclinatum , B. ceneum, Di- 

 chodontium pellucidum, Philonotis fontana, Meesea trichoides and 

 Aneura pinguis. 



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 Hepaticce are the most frequent: Scapania 

 subalpina, Alicularia scalaris, A. geoscypha, Lophozia quinquedentata 

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

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

 Intermixed with the above occur a very great number of species 

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

 Haplozia atrovirens, Cephalozia pleniceps, Dicranella crispa, Dichodon- 

 tium pellucidum, Aongstrcemia longipes, Didymodon rubellus, Disti- 

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

 inclinatum, B. affine, 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. Sometimes a moss-covering 

 of another composition is also met with, Hhacomitrium canescens 

 often forms extensive mats on wet sand} 7 ground. In North Ice- 

 land Timmia austriaca and Philonotis tomentella are found plenti- 

 fully in many places 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 



